Alessandro MARIANI

Pubblicazioni

Alessandro MARIANI

 

44 pubblicazioni classificate nel seguente modo:

Nr. doc. Classificazioni
43 1 Contributo su Rivista
1 2 Contributo in Volume
Anno
Risorse
2022
Tuning Polybenzimidazole Membrane by Immobilizing a Novel Ionic Liquid with Superior Oxygen Reduction Reaction Kinetics
CHEMISTRY OF MATERIALS
Autore/i: Hou, Hui; Mariani, Alessandro; Suo, Yanpeng; Gao, Xinpei; Giffin, Jürgen; Rodenbücher, Christian; Passerini, Stefano; Korte, Carsten
Classificazione: 1 Contributo su Rivista
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300112 Collegamento a IRIS

2022
Implications of Anion Structure on Physicochemical Properties of DBU-Based Protic Ionic Liquids
JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL
Autore/i: de Araujo Lima E Souza, Giselle; Di Pietro, Maria Enrica; Castiglione, Franca; Marques Mezencio, Pedro Henrique; Fazzio Martins Martinez, Patricia; Mariani, Alessandro; Schütz, Hanno Maria; Passerini, Stefano; Middendorf, Maleen; Schönhoff, Monika; Triolo, Alessandro; Appetecchi, Giovanni Battista; Mele, Andrea
Classificazione: 1 Contributo su Rivista
Abstract: Protic ionic liquids (PILs) are potential candidates as electrolyte components in energy storage devices. When replacing flammable and volatile organic solvents, PILs are expected to improve the safety and performance of electrochemical devices. Considering their technical application, a challenging task is the understanding of the key factors governing their intermolecular interactions and physicochemical properties. The present work intends to investigate the effects of the structural features on the properties of a promising PIL based on the 1,8-diazabicyclo[5.4.0]undec-7-ene (DBUH+) cation and the (trifluoromethanesulfonyl)(nonafluorobutanesulfonyl)imide (IM14-) anion, the latter being a remarkably large anion with an uneven distribution of the C-F pool between the two sides of the sulfonylimide moieties. For comparison purposes, the experimental investigations were extended to PILs composed of the same DBU-based cation and the trifluoromethanesulfonate (TFO-) or bis(trifluoromethanesulfonyl)imide (TFSI-) anion. The combined use of multiple NMR methods, thermal analyses, density, viscosity, and conductivity measurements provides a deep characterization of the PILs, unveiling peculiar behaviors in DBUH-IM14, which cannot be predicted solely on the basis of differences between aqueous pKa values of the protonated base and the acid (& UDelta;pKa). Interestingly, the thermal and electrochemical properties of DBUH-IM14 turn out to be markedly governed by the size and asymmetric nature of the anion. This observation highlights that the structural features of the precursors are an important tool to tailor the PIL's properties according to the specific application.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/306382 Collegamento a IRIS

2022
Concentrated Electrolytes Enabling Stable Aqueous Ammonium-Ion Batteries
ADVANCED MATERIALS
Autore/i: Han, Jin; Zarrabeitia, Maider; Mariani, Alessandro; Kuenzel, Matthias; Mullaliu, Angelo; Varzi, Alberto; Passerini, Stefano
Classificazione: 1 Contributo su Rivista
Abstract: Rechargeable aqueous batteries are promising devices for large-scale energy-storage applications because of their low-cost, inherent safety, and environmental friendliness. Among them, aqueous ammonium-ion (NH4+) batteries (AAIB) are currently emerging owing to the fast diffusion kinetics of NH4+. Nevertheless, it is still a challenge to obtain stable AAIB with relatively high output potential, considering the instability of many electrode materials in an aqueous environment. Herein, a cell based on a concentrated (5.8 m) aqueous (NH4)(2)SO4 electrolyte, ammonium copper hexacyanoferrate (N-CuHCF) as the positive electrode (cathode), and 3,4,9,10-perylene-bis(dicarboximide) (PTCDI) as the negative electrode (anode) is reported. The solvation structure, electrochemical properties, as well as the electrode-electrolyte interface and interphase are systematically investigated by the combination of theoretical and experimental methods. The results indicate a remarkable cycling performance of the low-cost rocking-chair AAIB, which offers a capacity retention of approximate to 72% after 1000 cycles and an average output potential of approximate to 1.0 V.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/306379 Collegamento a IRIS

2022
Difluorobenzene-Based Locally Concentrated Ionic Liquid Electrolyte Enabling Stable Cycling of Lithium Metal Batteries with Nickel-Rich Cathode
ADVANCED ENERGY MATERIALS
Autore/i: Liu, X; Mariani, A; Diemant, T; Di Pietro, Me; Dong, X; Kuenzel, M; Mele, A; Passerini, S
Classificazione: 1 Contributo su Rivista
Abstract: Lithium metal batteries (LMBs) with nickel-rich cathodes are promising candidates for next-generation, high-energy batteries. However, the highly reactive electrodes usually exhibit poor interfacial compatibility with conventional electrolytes, leading to limited cyclability. Herein, a locally concentrated ionic liquid electrolyte (LCILE) consisting of lithium bis(fluorosulfonyl)imide (LiFSI), 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide (EmimFSI), and 1,2-difluorobenzene (dFBn) is designed to overcome this challenge. As a cosolvent, dFBn not only promotes the Li+ transport with respect to the electrolyte based on the ionic liquid only, but also has beneficial effects on the electrode/electrolyte interphases (EEIs) on lithium metal anodes (LMAs) and LiNi0.8Mn0.1Co0.1O2 (NMC811) cathodes. As a result, the developed LCILE enables dendrite-free cycling of LMAs with a coulombic efficiency (CE) up to 99.57% at 0.5 mA cm(-2) and highly stable cycling of Li/NMC811 cells (4.4 V) at C/3 charge and 1 C discharge (1 C = 2 mA cm(-2)) for 500 cycles with a capacity retention of 93%. In contrast, the dFBn-free electrolyte achieves lithium stripping/plating CE, and the Li/NMC811 cells' capacity retention of only 98.22% and 16%, respectively under the same conditions. The insight into the coordination structure, promoted Li+ transport, and EEI characteristics gives fundamental information essential for further developing (IL-based) electrolytes for long-life, high-energy LMBs.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/306378 Collegamento a IRIS

2022
Stepping away from serendipity in Deep Eutectic Solvent formation: Prediction from precursors ratio
JOURNAL OF MOLECULAR LIQUIDS
Autore/i: Cappelluti, Francesco; Mariani, Alessandro; Bonomo, Matteo; Damin, Alessandro; Bencivenni, Luigi; Passerini, Stefano; Carbone, Marilena; Gontrani, Lorenzo
Classificazione: 1 Contributo su Rivista
Abstract: Deep Eutectic Solvents (DESs) are a class of environment friendly and cheap solvents that are effectively employed in many different fields; nevertheless, a thorough elucidation of their structure is still lacking and the unambiguous categorization of a mixture as a DES is challenging. Throughout this paper, we develop a procedure based on computational tools (supported by experimental data) that could help in making a priori predictions of DESs formation. After validating the approach with X-ray scattering data, a series of aromatic molecules (as Hydrogen Bond Donor, HBD) was investigated to corroborate the method that could be potentially extended to other DESs. The computational findings evidenced a remarkable and unprecedented predictive power. Furthermore, as a bridge between computed and experimental data, a linear correlation between the calculated chloride-HBD coordination number and the decrease of the freezing temperature of the mixtures is found, being 0.7 a threshold value to obtain a liquid eutectic mixture at room temperature as further validated by experimental Raman spectra. This approach has been preliminary tested also with DESs based on alternative HBDs (i.e., aliphatic alcohols, amines, and carboxylic acids), confirming the flexibility and the generality of the method.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/306384 Collegamento a IRIS

2022
Zinc-Ion Hybrid Supercapacitors Employing Acetate-Based Water-in-Salt Electrolytes
SMALL
Autore/i: Han, Jin; Mariani, Alessandro; Zarrabeitia, Maider; Jusys, Zenonas; Behm, R Jürgen; Varzi, Alberto; Passerini, Stefano
Classificazione: 1 Contributo su Rivista
Abstract: Halide-free, water-in-salt electrolytes (WiSEs) composed of potassium acetate (KAc) and zinc acetate (ZnAc2) are investigated as electrolytes in zinc-ion hybrid supercapacitors (ZHSs). Molecular dynamics simulations demonstrate that water molecules are mostly non-interacting with each other in the highly concentrated WiSEs, while "bulk-like water" regions are present in the dilute electrolyte. Among the various concentrated electrolytes investigated, the 30 m KAc and 1 m ZnAc2 electrolyte (30K1Zn) grants the best performance in terms of reversibility and stability of Zn plating/stripping while the less concentrated electrolyte cannot suppress corrosion of Zn and hydrogen evolution. The ZHSs utilizing 30K1Zn, in combination with a commercial activated carbon (AC) positive electrode and Zn as the negative electrode, deliver a capacity of 65 mAh g(-1) (based on the AC weight) at a current density of 5 A g(-1). They also offer an excellent capacity retention over 10 000 cycles and an impressive coulombic efficiency (approximate to 100%).
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/306380 Collegamento a IRIS

2022
Influence of Polymer Backbone Fluorination on the Electrochemical Behavior of Single-Ion Conducting Multiblock Copolymer Electrolytes
ACS MACRO LETTERS
Autore/i: Mayer, Alexander; Nguyen, Huu-Dat; Mariani, Alessandro; Diemant, Thomas; Lyonnard, Sandrine; Iojoiu, Cristina; Passerini, Stefano; Bresser, Dominic
Classificazione: 1 Contributo su Rivista
Abstract: The presence of fluorine, especially in the electrolyte, frequently has a beneficial effect on the performance of lithium batteries owing to, for instance, the stabilization of the interfaces and interphases with the positive and negative electrodes. However, the presence of fluorine is also associated with reduced recyclability and low biodegradability. Herein, we present a single-ion conducting multiblock copolymer electrolyte comprising a fluorine-free backbone and compare it with the fluorinated analogue reported earlier. Following a comprehensive physicochemical and electrochemical characterization of the copolymer with the fluorine-free backbone, the focus of the comparison with the fluorinated analogue was particularly on the electrochemical stability toward oxidation and reduction as well as the reactions occurring at the interface with the lithium-metal electrode. To deconvolute the impact of the fluorine in the ionic side chain and the copolymer backbone, suitable model compounds were identified and studied experimentally and theoretically. The results show that the absence of fluorine in the backbone has little impact on the basic electrochemical properties, such as the ionic conductivity, but severely affects the electrochemical stability and interfacial stability. The results highlight the need for a very careful design of the whole polymer for each desired application, essentially, just like for liquid electrolytes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/306381 Collegamento a IRIS

2022
Effect of organic cations in locally concentrated ionic liquid electrolytes on the electrochemical performance of lithium metal batteries
ENERGY STORAGE MATERIALS
Autore/i: Liu, X.; Mariani, A.; Zarrabeitia, M.; Di Pietro, M. E.; Dong, X.; Elia, G. A.; Mele, A.; Passerini, S.
Classificazione: 1 Contributo su Rivista
Abstract: Organic cations are essential components of locally concentrated ionic liquid electrolytes (LCILEs), but receive little attention. Herein, we demonstrate their significant influence on the electrochemical performance of lithium metal batteries via a comparison study of two LCILEs employing either 1‑butyl‑1-methylpyrrolidinium cation (Pyr14+) or 1-ethyl-3-methylimidazolium cation (Emim+). It is demonstrated that the structure of the organic cation in LCILEs has only a limited effect on the Li+- bis(fluorosulfonyl)imide anion (FSI−) coordination. Nonetheless, the coordination of FSI− with the organic cations is different. The less coordination of FSI− to Emim+ than to Pyr14+ results in the lower viscosity and faster Li+ transport in the Emim+-based electrolyte (EmiBE) than the Pyr14+-based electrolyte (PyrBE). Additionally, the chemical composition of the solid-electrolyte interphase (SEI) formed on lithium metal is affected by the organic cations. A more stable SEI growing in the presence of Emim+ leads to a higher lithium plating/stripping Coulombic efficiency (99.2%). As a result, Li/EmiBE/LiNi0.8Mn0.1Co0.1O2 cells exhibit a capacity of 185 mAh g−1 at 1C discharge (2 mA cm−2) and capacity retention of 96% after 200 cycles. Under the same conditions, PyrBE-based cells show only 34 mAh g−1 capacity with 39.6% retention.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300159 Collegamento a IRIS

2022
Molecular Insight into Microstructural and Dynamical Heterogeneities in Magnesium Ionic Liquid Electrolytes
THE JOURNAL OF PHYSICAL CHEMISTRY LETTERS
Autore/i: Su, L.; Gao, X.; Mariani, A.; Liu, X.; Passerini, S.; Gao, Y.; Zheng, L.
Classificazione: 1 Contributo su Rivista
Abstract: Ionic liquids (ILs) are promising designer solvents for multivalent electrolytes, enabling the modulation of molecular-level interactions of solvate species. The molecular mechanism of multivalent-ion clustering and its impact on electrolytes properties is far less studied than that of ion pairs. Herein, we explore the effect of ion clusters on the transport and electrochemical behavior of IL-based electrolytes for Mg batteries. Simulation and small-angle X-ray scattering results indicate that ILs with higher denticity effectively suppress ion agglomeration and parasitic reactions of the Mg electrolytes. Although ion clustering reduces the diffusivity of Mg2+, the Coulombic efficiency for the reversible Mg deposition/stripping process is improved, highlighting the importance of microstructural and dynamical heterogeneities in the rational design of enhanced multivalent electrolytes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300167 Collegamento a IRIS

2021
The unseen evidence of Reduced Ionicity: The elephant in (the) room temperature ionic liquids
JOURNAL OF MOLECULAR LIQUIDS
Autore/i: Mariani, A.; Bonomo, M.; Gao, X.; Centrella, B.; Nucara, A.; Buscaino, R.; Barge, A.; Barbero, N.; Gontrani, L.; Passerini, S.
Classificazione: 1 Contributo su Rivista
Abstract: The unambiguous quantification of the proton transfer in Protic Ionic Liquids (PILs) and its differentiation from the concept of ionicity are still unsolved questions. Albeit researchers awfully quickly treat them as synonyms, the two concepts are intrinsically different and imply a dramatic modification in the expected chemical and physical properties of a PIL. Some attempts have been made to shed light on this discrimination, but single-technique-based approaches fail in giving a clear answer. Aiming at definitively figuring out the differentiation between proton transfer and ionicity, we performed a multi-technique analysis (NMR, Raman, IR, thermal and electrochemical analyses, among others). Indeed, thermal and spectroscopic analyses are employed to determine the acid strength's role in ions' complete formation. To overcome the ambiguity between ionicity and formation degree, we introduce a new paradigm where Reduced Ionicity accounts for both the quantities mentioned above. The reduced ionicity directly affects the thermal stability, the phase behavior, and the spectroscopic observations, resulting in particular features in NMR and vibrational spectra. The combination of physical-chemical analyses and Pulsed-Gradient Spin-Echo (PGSE) NMR allows determining the reduced ionicity (and not the ionicity, as reported so far) of the investigated systems. In this context, being the proton transfer not quantitatively accessible directly, the reduced ionicity of a reference series of triethylamine-based PILs is investigated through transport properties as a function of temperature. Our findings point towards a substantial dependence of the reduced ionicity by the acid strength and the anion's coordination power. Furthermore, some interesting insights about the proton transfer are obtained, combining all the findings collected.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300172 Collegamento a IRIS

2021
Enhanced Li+ Transport in Ionic Liquid-Based Electrolytes Aided by Fluorinated Ethers for Highly Efficient Lithium Metal Batteries with Improved Rate Capability
SMALL METHODS
Autore/i: Liu, X.; Zarrabeitia, M.; Mariani, A.; Gao, X.; Schutz, H. M.; Fang, S.; Bizien, T.; Elia, G. A.; Passerini, S.
Classificazione: 1 Contributo su Rivista
Abstract: FSI−-based ionic liquids (ILs) are promising electrolyte candidates for long-life and safe lithium metal batteries (LMBs). However, their practical application is hindered by sluggish Li+ transport at room temperature. Herein, it is shown that additions of bis(2,2,2-trifluoroethyl) ether (BTFE) to LiFSI-Pyr14FSI ILs can effectively mitigate this shortcoming, while maintaining ILs′ high compatibility with lithium metal. Raman spectroscopy and small-angle X-ray scattering indicate that the promoted Li+ transport in the optimized electrolyte, [LiFSI]3[Pyr14FSI]4[BTFE]4 (Li3Py4BT4), originates from the reduced solution viscosity and increased formation of Li+-FSI− complexes, which are associated with the low viscosity and non-coordinating character of BTFE. As a result, Li/LiFePO4 (LFP) cells using Li3Py4BT4 electrolyte reach 150 mAh g−1 at 1 C rate (1 mA cm−2) and a capacity retention of 94.6% after 400 cycles, revealing better characteristics with respect to the cells employing the LiFSI-Pyr14FSI (operate only a few cycles) and commercial carbonate (80% retention after only 218 cycles) electrolytes. A wide operating temperature (from −10 to 40 °C) of the Li/Li3Py4BT4/LFP cells and a good compatibility of Li3Py4BT4 with LiNi0.5Mn0.3Co0.2O2 (NMC532) are demonstrated also. The insight into the enhanced Li+ transport and solid electrolyte interphase characteristics suggests valuable information to develop IL-based electrolytes for LMBs.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300174 Collegamento a IRIS

2021
Green and low-cost acetate-based electrolytes for the highly reversible zinc anode
JOURNAL OF POWER SOURCES
Autore/i: Han, J.; Mariani, A.; Varzi, A.; Passerini, S.
Classificazione: 1 Contributo su Rivista
Abstract: A highly concentrated solution of potassium, lithium and zinc acetate is proposed as green “Water-in-Salt” electrolyte (WiSE). In this halide-free electrolyte, investigated by classical Molecular Dynamics simulations, differential scanning calorimetry (DSC) and Raman spectroscopy, the water molecules are coordinated by the acetate anion as well as the various cations. As a result of the strong coordination of water molecules, the WiSE enables outstanding zinc (Zn) plating/stripping average Coulombic efficiency (CE) (99.6%) and long-term cycling stability. Dual ion cells using this electrolyte and featuring the Zn metal anode and either LiFePO4 (LFP) or spinel LiMn2O4 (LMO)-based cathodes deliver discharge capacity of 155 mA h g−1 and 121 mA h g−1 at 0.05C, respectively. The Zn/LFP cells demonstrate better cycling stability compared to Zn/LMO, which is attributed to the more stable crystal structure of LFP.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300118 Collegamento a IRIS

2021
Assessing the structure of protic ionic liquids based on triethylammonium and organic acid anions
JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL
Autore/i: Bodo, E.; Bonomo, M.; Mariani, A.
Classificazione: 1 Contributo su Rivista
Abstract: We present a computational analysis of the short-range structure of three protic ionic liquids based on strong organic acids: trifluoracetate, methanesulfonate, and triflate of triethylammonium. Accurate ab initio computations carried out on the gas-phase dimers show that the protonation of triethylamine is spontaneous. We have identified the anion-cation binding motif that is due to the presence of a strong hydrogen bond and to electrostatic interactions. The strength of the hydrogen bond and the magnitude of the binding energy decrease in the order trifluoroacetate ≳ methanesulfonate > triflate. The corresponding simulations of the bulk phases, obtained using a semiempirical evaluation of the interatomic forces, reveal that on short timescales, the state of the three liquids remains highly ionized and that the gas-phase cation-/anion-binding motif is preserved while no other peculiar structural features seem to emerge.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300163 Collegamento a IRIS

2021
Erratum: Acidic Ionic Liquids Enabling Intermediate Temperature Operation Fuel Cells (ACS Appl. Mater. Interfaces (2021) 13: 7 (8370-8382) DOI: 10.1021/acsami.0c20679)
ACS APPLIED MATERIALS & INTERFACES
Autore/i: Hou, H.; Schutz, H. M.; Giffin, J.; Wippermann, K.; Gao, X.; Mariani, A.; Passerini, S.; Korte, C.
Classificazione: 1 Contributo su Rivista
Abstract: Page 8372 in section 2.3. ORR Kinetics. There is an error in the sentence "The effective surface of the WE is 0.011 cm2". The actual electrode surface of the WE is 0.301 cm2. Thus, the corresponding current densities in Figures 5, 7, and S6, the Table of Contents (TOC) graphic, and Table 3 are recalculated and corrected here. (Figure presented).
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300153 Collegamento a IRIS

2021
Acidic ionic liquids enabling intermediate temperature operation fuel cells
ACS APPLIED MATERIALS & INTERFACES
Autore/i: Hou, H.; Schutz, H. M.; Giffin, J.; Wippermann, K.; Gao, X.; Mariani, A.; Passerini, S.; Korte, C.
Classificazione: 1 Contributo su Rivista
Abstract: Herein we show that protic ionic liquids (PILs) are promising electrolytes for fuel cells operating in the temperature range 100−120 °C. N,N-Diethyl-N-methyl-3-sulfopropan-1-ammonium hydrogen sulfate ([DEMSPA][HSA]), N,N-diethyl-N-methyl-3-sulfopropan-1-ammonium triflate ([DEMSPA][TfO]), N,N-diethyl-3-sulfopropan-1-ammonium hydrogen sulfate ([DESPA][HSA]), and N,N-diethyl-3-sulfopropan-1-ammonium triflate ([DESPA][TfO]) are investigated in this study with regard to their specific conductivity, thermal stability, viscosity, and electrochemical properties. The [DEMSPA][TfO] and [DESPA][TfO] electrolytes offer high limiting current densities for the oxygen reduction reaction (ORR) on platinum electrodes, that is, about 1 order of magnitude larger than 98% H3PO4. This is explained by the minor poisoning of the Pt catalyst and the significantly larger product of the oxygen self-diffusion coefficient and concentration in these two PILs.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300124 Collegamento a IRIS

2021
Redox-Mediated Red-Phosphorous Semi-Liquid Anode Enabling Metal-Free Rechargeable Na-Seawater Batteries with High Energy Density
ADVANCED ENERGY MATERIALS
Autore/i: Kim, Y.; Varzi, A.; Mariani, A.; Kim, G. -T.; Kim, Y.; Passerini, S.
Classificazione: 1 Contributo su Rivista
Abstract: Sodium-seawater batteries (Na-SWB) are considered among the most promising electrochemical devices for large-scale energy storage and the marine sector. In fact, by employing an open-structured cathode, they benefit from the unlimited supply of sodium from seawater. This means, that the energy of such systems is intrinsically limited by the capacity of the anode. In order to increase the energy of Na-SWB, it is therefore necessary to introduce a high-capacity anode such as, e.g., red phosphorus. However, due to its large volume changes upon charge/discharge processes, obtaining thick electrodes and large areal capacity is extremely challenging. Herein, the areal/absolute capacity of the red phosphorus anode is increased by employing a semi-liquid electrode, which includes two redox mediators, i.e., sodium-biphenyl and sodium-pyrene, as reducing and oxidizing species for the exploitation of the full red phosphorus capacity. As a result, the red phosphorus semi-liquid anode in Na-SWB provides a high-capacity of 15 mAh cm–2 in a static anode, showing great energy storage potential for operation in flow-mode when storing the semi-liquid negative electrode in a storage tank.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300175 Collegamento a IRIS

2021
Nonfluorinated Ionic Liquid Electrolytes for Lithium Metal Batteries: Ionic Conduction, Electrochemistry, and Interphase Formation
ADVANCED ENERGY MATERIALS
Autore/i: Karimi, N.; Zarrabeitia, M.; Mariani, A.; Gatti, D.; Varzi, A.; Passerini, S.
Classificazione: 1 Contributo su Rivista
Abstract: Cyano-based ionic liquids (ILs) are prime candidates for the manufacturing of cheaper and safer batteries due to their inherently low-volatility and absence of expensive fluorinated species. In this work, N-methyl-N-butylpyrrolidinium (Pyr14)-based ILs featuring two different cyano-based anions, i.e., dicyanamide (DCA) and tricyanomethanide (TCM), and their mixture with the respective Li salts (1:9 salt:IL mole ratio), alongside their combination (DCA–TCM), are evaluated as potential electrolytes for lithium metal batteries (LMBs). The electrolytes display significant ionic conductivity at room temperature (5 mS cm−1) alongside an electrochemical stability window up to 4 V, suitable for low-voltage LMBs such as Li–sulfur, as well as promising cycling stability. In addition to the detailed physicochemical (viscosity, conductivity) and electrochemical (electrochemical stability window, stripping/plating, and impedance test in symmetrical Li cells) characterization, the solid electrolyte interphase (SEI) formed in this class of ionic liquids is studied for the first time. X-ray photoelectron spectroscopy (XPS) provides evidence for an SEI dominated by a polymer-rich layer including carbon–nitrogen single, double, and triple bonds, which provides high ionic conductivity and mechanical stability, leading to the aforementioned cycling stability. Finally, a molecular insight is achieved by density functional theory (DFT) and classic molecular dynamics simulations both supporting the experimental evidence.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300173 Collegamento a IRIS

2021
On the nanoscopic structural heterogeneity of liquidn-alkyl carboxylic acids
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Autore/i: Mariani, A.; Innocenti, A.; Varzi, A.; Passerini, S.
Classificazione: 1 Contributo su Rivista
Abstract: Herein we report the first in-depth structural characterisation of simple linear carboxylic acids with alkyl tail length ranging from one to six carbon atoms. By means of the SWAXS technique, a pronounced nanoscopic heterogeneity evolving along the aliphatic portion of the molecule is highlighted.Viaclassical molecular dynamics, the origin of such heterogeneity is unambiguously assigned to the existence of aliphatic domains resulting from the self-segregation of the polar and apolar portions of the molecules. Furthermore, the structural correlation of aliphatic-separated polar domains is responsible for observing the so-called “pre-peak” in the SAXS region.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300138 Collegamento a IRIS

2020
Packing and dynamics of a protein solution approaching the jammed state
SOFT MATTER
Autore/i: Begam, N.; Da Vela, S.; Matsarskaia, O.; Braun, M. K.; Mariani, A.; Zhang, F.; Schreiber, F.
Classificazione: 1 Contributo su Rivista
Abstract: The packing of proteins and their collective behavior in crowded media is crucial for the understanding of biological processes. Here we study the structural and dynamical evolution of solutions of the globular protein bovine serum albumin with increasing concentration via drying using small angle X-ray scattering and dynamic light scattering. We probe an evolving correlation peak on the scattering profile, corresponding to the inter-protein distance, ξ, which decreases following a power law of the protein volume fraction, ϕ. The rate of decrease in ξ becomes faster above a protein concentration of ∼200 mg ml-1 (ϕ = 0.15). The power law exponent changes from 0.33, which is typical of colloidal or protein solutions, to 0.41. During the entire drying process, we observe the development and the growth of two-step relaxation dynamics with increasing ϕ as revealed by dynamic light scattering. We find three different regimes of the dependence of ξ as a function of ϕ. In the dilute regime (ϕ < 0.22), protein molecules are far apart from each other compared to their size. In this case, the dynamics mainly corresponds to Brownian motion. At an intermediate concentration (0.22 < ϕ < 0.47), inter-protein distances become comparable to the size of protein molecules, leading to a preferential orientation of the ellipsoidal protein molecules along with a possible deformation. In this regime, the dynamics shows two distinct relaxation times. At a very high concentration (ϕ > 0.47), the system reaches a jammed state. Subsequently, the secondary relaxation time in this state becomes extremely slow. In this state, the protein molecules have approximately one hydration layer. This study contributes to the understanding of protein molecular packing in crowded environments and the phenomenon of density-driven jamming for soft matter systems. This journal is
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300161 Collegamento a IRIS

2020
Interplay between Glass Formation and Liquid-Liquid Phase Separation Revealed by the Scattering Invariant
THE JOURNAL OF PHYSICAL CHEMISTRY LETTERS
Autore/i: Da Vela, S.; Begam, N.; Dyachok, D.; Schaufele, R. S.; Matsarskaia, O.; Braun, M. K.; Girelli, A.; Ragulskaya, A.; Mariani, A.; Zhang, F.; Schreiber, F.
Classificazione: 1 Contributo su Rivista
Abstract: The interplay of the glass transition with liquid-liquid phase separation (LLPS) is a subject of intense debate. We use the scattering invariant Q to probe how approaching the glass transition affects the shape of LLPS boundaries in the temperature/volume fraction plane. Two protein systems featuring kinetic arrest with a lower and an upper critical solution temperature phase behavior, respectively, are studied varying the quench depth. Using Q we noninvasively identify system-dependent differences for the effect of glass formation on the LLPS boundary. The glassy dense phase appears to enter the coexistence region for the albumin-YCl3 system, whereas it follows the equilibrium binodal for the γ-globulin-PEG system.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300162 Collegamento a IRIS

2020
Alkoxy-functionalized ionic liquid electrolytes: Understanding ionic coordination of calcium ion speciation for the rational design of calcium electrolytes
ENERGY & ENVIRONMENTAL SCIENCE
Autore/i: Gao, X.; Liu, X.; Mariani, A.; Elia, G. A.; Lechner, M.; Streb, C.; Passerini, S.
Classificazione: 1 Contributo su Rivista
Abstract: There is growing interest in the rational design of electrolytes for multivalent-ion batteries by tuning the molecular-level interactions of solvate species present in the electrolytes. Herein, we report our effort to control Ca-ion speciation in ionic liquid (IL) based electrolytes through the design of alkoxy-functionalized cations. Quantitative analysis reveals that the alkoxy-functionalized ammonium cation (N07+), bearing seven ether oxygen atoms, can effectively displace the bis(trifluoromethanesulfonyl)imide anion (TFSI-) from the Ca2+ ion coordination sphere, facilitating the reversible Ca deposition/stripping process. More importantly, post-analysis of Ca deposits surface chemistry and density functional theory calculations of Ca-ion speciation indicate the formation of an organic-rich, but inorganic-poor solid electrolyte interphase layer, which enables Ca2+ ion diffusion rather than passivating the Ca metal electrode. Finally, as a proof-of-concept, a prototype Ca/V2O5 cell using the optimized IL-based electrolyte ([Ca(BH4)2]0.05[N07TFSI]0.95) is demonstrated for the first time, exhibiting a remarkable initial discharge capacity of 332 mA h g-1 and reversible capacity of 244 mA h g-1.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300154 Collegamento a IRIS

2020
Highly Reversible Sodiation of Tin in Glyme Electrolytes: The Critical Role of the Solid Electrolyte Interphase and Its Formation Mechanism
ACS APPLIED MATERIALS & INTERFACES
Autore/i: Qin, B.; Schiele, A.; Jusys, Z.; Mariani, A.; Diemant, T.; Liu, X.; Brezesinski, T.; Behm, R. J.; Varzi, A.; Passerini, S.
Classificazione: 1 Contributo su Rivista
Abstract: Utilization of high-capacity alloying anodes is a promising yet extremely challenging strategy in building high energy density alkali-ion batteries (AIBs). Excitingly, it was very recently found that the (de-)sodiation of tin (Sn) can be a highly reversible process in specific glyme electrolytes, enabling high specific capacities close to the theoretical value of 847 mA h g-1. The unique solid electrolyte interphase (SEI) formed on Sn electrodes, which allows highly reversible sodiation regardless of the huge volume expansion, is herein demonstrated according to a series of in situ and ex situ characterization techniques. The SEI formation process mainly involves NaPF6 decomposition and the polymerization/oligomerization of the glyme solvent, which is induced by the catalytic effect of tin, specifically. This work provides a paradigm showing how solvent, salt, and electrode materials synergistically mediate the SEI formation process and obtains new insights into the unique interfacial chemistry between Na-alloying electrodes and glyme electrolytes, which is highly enlightening in building high energy density AIBs.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300126 Collegamento a IRIS

2020
Disclosing the hierarchical structure of ionic liquid mixtures by multiscale computational methods
Theoretical and Computational Approaches to Predicting Ionic Liquid Properties
Autore/i: Mariani, A.; Engelbrecht, L.; Le Donne, A.; Mocci, F.; Bodo, E.; Passerini, S.
Editore: Elsevier
Classificazione: 2 Contributo in Volume
Abstract: This chapter deals with the structural analysis of ionic liquid-containing mixtures through multiscale computational methods. The chapter is divided into two sections, dealing with a basic introduction to the topic, and a more in-depth presentation of four different computational methods typically used to simulate the structural and dynamical properties of complex liquid systems. Initially, the concept of the structure of a liquid is discussed, providing definitions and some examples. Subsequently, the main features of the experimental technique based on X-ray scattering are presented, which allow accessing structural information of amorphous systems. A short introduction of the laws governing the scattering phenomenon, and how scattered photons can provide information about the structure of a system is also presented. A significant part of this chapter is devoted to introducing four of the most used state-of-the-art computational methods, namely density functional theory “static” optimization, semiempirical molecular dynamics, classical molecular dynamics, and coarse-grained molecular dynamics. The starting point is the quantastic treatment of the system, in which only minimal approximations are used. The reader is then guided toward successive approximations enabling to explore different system sizes and timescales. The intricate system ethylammonium nitrate:acetonitrile 1:9 binary mixture is taken as a case study to show what the four obtained models can return in terms of characterization. The final picture describes how the various methods are fundamentally complementary to each other, meaning that there is nothing as a “best” method.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300176 Collegamento a IRIS

2020
Anion exchange membrane electrolyte preserving inverse Ia3‾d bicontinuous cubic phase: Effect of microdomain morphology on selective ion transport
JOURNAL OF MEMBRANE SCIENCE
Autore/i: Sun, N.; Lu, F.; Mariani, A.; Passerini, S.; Gao, X.; Zheng, L.
Classificazione: 1 Contributo su Rivista
Abstract: The understanding of structure-morphology-property relationships is pivotal in the rational design of ion-exchange membranes with well-balanced properties. Prior observations have led to the general perception that well-defined hydrophilic/hydrophobic phase-segregated morphologies are relevant for efficient ion transport. On this basis, herein, the membrane microdomain morphology, along with its ion transport mechanisms, are discussed with respect to permselectivity. We propose and demonstrate a simple approach to construct liquid-crystalline anion-exchange membrane preserving inverse bicontinuous cubic structure. The resulting membrane exhibits improved hydroxide conductivity, superior water management ability, and enhanced alkaline stability. More importantly, the preserved 3D-interconnected ion channels selectively transport hydroxide via a reduced migration barrier, while inhibiting crossover of hydrated ions and organic solutes. These results highlight the outstanding potential of cubic liquid crystal mesophases as an attractive material for designing membranes with well-defined ion channels, while offering mechanistic insights into the structure-morphology-property relationships of membrane electrolytes for advanced energy applications.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300127 Collegamento a IRIS

2020
Gelified acetate-based water-in-salt electrolyte stabilizing hexacyanoferrate cathode for aqueous potassium-ion batteries
ENERGY STORAGE MATERIALS
Autore/i: Han, J.; Mariani, A.; Zhang, H.; Zarrabeitia, M.; Gao, X.; Carvalho, D. V.; Varzi, A.; Passerini, S.
Classificazione: 1 Contributo su Rivista
Abstract: Potassium acetate (KAc)-based “Water-in-salt” electrolytes (WiSE) are herein studied by Raman and classical Molecular Dynamics (MD), evidencing the notably suppressed water activity of these WiSEs since water can be effectively coordinated by both the acetate anion and the potassium cation. The overall molecular arrangement is found to approach the “sponge-like” structure observed in certain ionic liquids. With properly tuned composition, such WiSE can also be compatible with Al current collectors, as demonstrated by extensive electrochemical, scanning electronic microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) analysis. The use of low-cost potassium manganese hexacyanoferrate (KMHCF) in conjunction with these electrolytes, however, is affected by poor cycling performance due to the limited stability of the cathode material in the alkaline environment. Promisingly though, the stability of KMHCF is found to improve substantially when the electrolyte is gelified by adding a small amount (2 ​wt%) of carboxymethyl cellulose (CMC), as testified by the enhanced capacity retention as well as the higher Coulombic efficiency (>99.3%). In particular, Mn and Fe dissolution are suppressed and, as suggested by MD simulations, K cations diffusion may be promoted in the gel electrolyte compared to the liquid system.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300123 Collegamento a IRIS

2020
Halide-free water-in-salt electrolytes for stable aqueous sodium-ion batteries
NANO ENERGY
Autore/i: Han, J.; Zarrabeitia, M.; Mariani, A.; Jusys, Z.; Hekmatfar, M.; Zhang, H.; Geiger, D.; Kaiser, U.; Behm, R. J.; Varzi, A.; Passerini, S.
Classificazione: 1 Contributo su Rivista
Abstract: The extensive investigation via classical Molecular Dynamics (MD) simulations of the halide-free “water-in-salt” electrolyte (WiSE) consisting of sodium acetate (8 m) and potassium acetate (32 m), unveils the interactions between cations, anions and water molecules. The WiSE's application as electrolyte in symmetric aqueous sodium-ion batteries, featuring NASICON-type Na2VTi(PO4)3/C (NVTP/C) as active material at both the positive and the negative electrode, is also reported. In situ X-ray diffraction (XRD) measurements resolve the structural evolution of NVTP/C during the highly reversible sodium de/intercalation. Differential Electrochemical Mass Spectrometry (DEMS) confirms the remarkable stability of the highly concentrated electrolyte. Symmetric cells employing two NVTP/C electrodes and a green 32K8N electrolyte show an average discharge voltage of 1.13 V with stable cycling performance and a coulombic efficiency above 99.1% at 1C and 99.9% at 10C over 500 cycles. Compared to the fluorinated 9.2 m NaOTF, the 32K8N electrolyte has substantially lower cost, environmental impact and superior coulombic efficiency in symmetric cells.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300156 Collegamento a IRIS

2019
Concentrated Ionic-Liquid-Based Electrolytes for High-Voltage Lithium Batteries with Improved Performance at Room Temperature
CHEMSUSCHEM
Autore/i: Gao, X.; Wu, F.; Mariani, A.; Passerini, S.
Classificazione: 1 Contributo su Rivista
Abstract: Ionic liquids (ILs) have been widely explored as alternative electrolytes to combat the safety issues associated with conventional organic electrolytes. However, hindered by their relatively high viscosity, the electrochemical performances of IL-based cells are generally assessed at medium-to-high temperature and limited cycling rate. A suitable combination of alkoxy-functionalized cations with asymmetric imide anions can effectively lower the lattice energy and improve the fluidity of the IL material. The Li/Li1.2Ni0.2Mn0.6O2 cell employing N-N-diethyl-N-methyl-N-(2-methoxyethyl)ammonium (fluorosulfonyl)(trifluoromethanesulfonyl)imide (DEMEFTFSI)-based electrolyte delivered an initial capacity of 153 mAh g−1 within the voltage range of 2.5–4.6 V, with a capacity retention of 65.5 % after 500 cycles and stable coulombic efficiencies exceeding 99.5 %. Moreover, preliminary battery tests demonstrated that the drawbacks in terms of rate capability could be improved by using Li-concentrated IL-based electrolytes. The improved room-temperature rate performance of these electrolytes was likely owing to the formation of Li+-containing aggregate species, changing the concentration-dependent Li-ion transport mechanism.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300160 Collegamento a IRIS

2019
Statistic-driven proton transfer affecting nanoscopic organization in an ethylammonium nitrate ionic liquid and 1,4-diaminobutane binary mixture: A steamy pizza model
SYMMETRY
Autore/i: Mariani, A.; Bonomo, M.; Passerini, S.
Classificazione: 1 Contributo su Rivista
Abstract: Herein, we report on the theoretical and experimental investigation of the chemical equilibrium in a Ethylammonium Nitrate (EAN)/1,4-Diaminobutane (DAB) binary mixture displaying a significant excess of the latter component (namely, a 1:9 mole ratio). Both the neutral compounds, i.e., ethylamine (EtNH2) and DAB, present very similar chemical properties, especially concerning their basic strength, resulting in a continuous jump of the proton from the ethylammonium to the diamine (and vice-versa). Due to the significant excess of DAB, the proton is (statistically) expected to be bound to one of its nitrogen atoms, leading to the formation of a new (ternary) mixture containing DAB (ca. 80%), ethylamine (ca. 10%) and 4-amino-1-butylammonium nitrate (ABAN, ca. 10%). This is probed by means of SAXS measurements, showing LqE (low q excess) that increases over time. This feature tends to stabilize after approximately one day. When the measurement is repeated after one year, the LqE feature shows an increased intensity. Based on the results of our simulations, we suggest that this phenomenon is likely due to partial ethylamine evaporation, pushing the equilibrium toward the formation of ABAN.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300121 Collegamento a IRIS

2019
Evolution of Structure in a Comb Copolymer-Surfactant Coacervate
MACROMOLECULES
Autore/i: Fanova, A.; Janata, M.; Filippov, S. K.; Slouf, M.; Netopilik, M.; Mariani, A.; Stepanek, M.
Classificazione: 1 Contributo su Rivista
Abstract: The interaction between a double-hydrophilic comb copolymer with the polyanionic backbone poly[methacrylic acid-stat-poly(ethylene glycol) methyl ether methacrylate] (PMAA-PEGMA) and the cationic surfactant N-dodecylpyridinium chloride (DPCl) was studied in alkaline aqueous solutions by using a combination of light and X-ray scattering techniques, covering 5 orders of magnitude in space (the q vector range from 10-5 to 5 nm-1) and time (from milliseconds to several hours). The results showed that the polyelectrolyte-surfactant (PE-S) complex of PMAA-PEGMA and DPCl forms micrometer-sized coacervate particles containing collapsed PMAA-PEGMA chains with attached and densely packed DPCl micelles. Time-resolved SAXS measurements coupled with a stopped-flow apparatus revealed that the phase separation of the PE-S complex into a coacervate phase occurred in <25 ms after mixing the polyelectrolyte and the surfactant. Thus, microphase separation was faster than the self-assembly of DPCl into densely packed micelles. The terminal stages of polyelectrolyte-surfactant coacervation were dictated by the Ostwald ripening of the droplets in the time range of hours.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300115 Collegamento a IRIS

2019
Prototype rechargeable magnesium batteries using ionic liquid electrolytes
JOURNAL OF POWER SOURCES
Autore/i: Gao, X.; Mariani, A.; Jeong, S.; Liu, X.; Dou, X.; Ding, M.; Moretti, A.; Passerini, S.
Classificazione: 1 Contributo su Rivista
Abstract: Understanding Mg-ion speciation is of utmost importance to the rational design of electrolytes for rechargeable magnesium batteries. Herein, we report an effort to better understand Mg-ion speciation in ionic liquid (IL) electrolytes through the design of alkoxy-functionalized cations with different alkoxy substituent. In contrast with previous studies focusing on the coordination sphere of Mg2+, the comparison of Raman spectroscopy, electrochemical and DFT calculation results of various IL-based electrolytes suggests that the coordination sphere of transient Mg+ plays a key role in Mg reversible deposition/dissolution process. Finally, a prototype Mg/V2O5 cell using the noncorrosive IL-based electrolyte is demonstrated for the first time, exhibiting a remarkable initial discharge capacity of 140 mAh g−1 and reversible capacity of 100 mAh g−1.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300139 Collegamento a IRIS

2019
Phase-Separation Kinetics in Protein-Salt Mixtures with Compositionally Tuned Interactions
JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL
Autore/i: Matsarskaia, O.; Da Vela, S.; Mariani, A.; Fu, Z.; Zhang, F.; Schreiber, F.
Classificazione: 1 Contributo su Rivista
Abstract: Liquid-liquid phase separation (LLPS) in protein systems is relevant for many phenomena, from protein condensation diseases to subcellular organization to possible pathways toward protein crystallization. Understanding and controlling LLPS in proteins is therefore highly relevant for various areas of (biological) soft matter research. Solutions of the protein bovine serum albumin (BSA) have been shown to have a lower critical solution temperature-LLPS (LCST-LLPS) induceable by multivalent salts. Importantly, the nature of the multivalent cation used influences the LCST-LLPS in such systems. Here, we present a systematic ultrasmall-angle X-ray scattering investigation of the kinetics of LCST-LLPS of BSA in the presence of different mixtures of HoCl 3 and LaCl 3 , resulting in different effective interprotein attraction strengths. We monitor the characteristic length scales ξ(t, T fin ) after inducing LLPS by subjecting the respective systems to temperature jumps in their liquid-liquid coexistence regions. With increasing interprotein attraction and increasing T fin , we observe an increasing deviation from the growth law of ξ ∼ t 1/3 and an increased trend toward arrest. We thus establish a multidimensional method to tune phase transitions in our systems. Our findings help shed light on general questions regarding LLPS and the tunability of its kinetics in both proteins and colloidal systems.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300125 Collegamento a IRIS

2019
Protein Short-Time Diffusion in a Naturally Crowded Environment
THE JOURNAL OF PHYSICAL CHEMISTRY LETTERS
Autore/i: Grimaldo, M.; Lopez, H.; Beck, C.; Roosen-Runge, F.; Moulin, M.; Devos, J. M.; Laux, V.; Hartlein, M.; Da Vela, S.; Schweins, R.; Mariani, A.; Zhang, F.; Barrat, J. -L.; Oettel, M.; Forsyth, V. T.; Seydel, T.; Schreiber, F.
Classificazione: 1 Contributo su Rivista
Abstract: The interior of living cells is a dense and polydisperse suspension of macromolecules. Such a complex system challenges an understanding in terms of colloidal suspensions. As a fundamental test we employ neutron spectroscopy to measure the diffusion of tracer proteins (immunoglobulins) in a cell-like environment (cell lysate) with explicit control over crowding conditions. In combination with Stokesian dynamics simulation, we address protein diffusion on nanosecond time scales where hydrodynamic interactions dominate over negligible protein collisions. We successfully link the experimental results on these complex, flexible molecules with coarse-grained simulations providing a consistent understanding by colloid theories. Both experiments and simulations show that tracers in polydisperse solutions close to the effective particle radius R eff = R i31/3 diffuse approximately as if the suspension was monodisperse. The simulations further show that macromolecules of sizes R > R eff (R < R eff ) are slowed more (less) effectively even at nanosecond time scales, which is highly relevant for a quantitative understanding of cellular processes.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300147 Collegamento a IRIS

2018
Tuning phase transitions of aqueous protein solutions by multivalent cations
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Autore/i: Matsarskaia, O.; Roosen-Runge, F.; Lotze, G.; Moller, J.; Mariani, A.; Zhang, F.; Schreiber, F.
Classificazione: 1 Contributo su Rivista
Abstract: In the presence of trivalent cations, negatively charged globular proteins show a rich phase behaviour including reentrant condensation, crystallisation, clustering and lower critical solution temperature metastable liquid-liquid phase separation (LCST-LLPS). Here, we present a systematic study on how different multivalent cations can be employed to tune the interactions and the associated phase behaviour of proteins. We focus our investigations on the protein bovine serum albumin (BSA) in the presence of HoCl3, LaCl3 and YCl3. Using UV-Vis spectroscopy and small-angle X-ray scattering (SAXS), we find that the interprotein attraction induced by Ho3+ is very strong, while the one induced by La3+ is comparatively weak when comparing the data to BSA-Y3+ systems based on our previous work. Using zeta potential and isothermal titration calorimetry (ITC) measurements, we establish different binding affinities of cations to BSA with Ho3+ having the highest one. We propose that a combination of different cation features such as radius, polarisability and in particular hydration effects determine the protein-protein interaction induced by these cations. Our findings imply that subtle differences in cation properties can be a sensitive tool to fine-tune protein-protein interactions and phase behaviour in solution.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300164 Collegamento a IRIS

2018
Structure and dynamics of propylammonium nitrate-acetonitrile mixtures: An intricate multi-scale system probed with experimental and theoretical techniques
THE JOURNAL OF CHEMICAL PHYSICS
Autore/i: Campetella, M.; Mariani, A.; Sadun, C.; Wu, B.; Castner, E. W.; Gontrani, L.
Classificazione: 1 Contributo su Rivista
Abstract: In this article, we report the study of structural and dynamical properties for a series of acetonitrile/propylammonium nitrate mixtures as a function of their composition. These systems display an unusual increase in intensity in their X-ray diffraction patterns in the low-q regime, and their 1H-NMR diffusion-ordered NMR spectroscopy (DOSY) spectra display unusual diffusivities. However, the magnitude of both phenomena for mixtures of propylammonium nitrate is smaller than those observed for ethylammonium nitrate mixtures with the same cosolvent, suggesting that the cation alkyl tail plays an important role in these observations. The experimental X-ray scattering data are compared with the results of molecular dynamics simulations, including both ab initio studies used to interpret short-range interactions and classical simulations to describe longer range interactions. The higher level calculations highlight the presence of a strong hydrogen bond network within the ionic liquid, only slightly perturbed even at high acetonitrile concentration. These strong interactions lead to the symmetry breaking of the NO3- vibrations, with a splitting of about 88 cm-1 in the ν3 antisymmetric stretch. The classical force field simulations use a greater number of ion pairs, but are not capable of fully describing the longest range interactions, although they do successfully account for the observed concentration trend, and the analysis of the models confirms the nano-inhomogeneity of these kinds of samples.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300168 Collegamento a IRIS

2017
A joint experimental and computational study on ethylammonium nitrate-ethylene glycol 1:1 mixture. Structural, kinetic, dynamic and spectroscopic properties
JOURNAL OF MOLECULAR LIQUIDS
Autore/i: Mariani, A.; Bencivenni, L.; Caminiti, R.; Gontrani, L.; Campetella, M.; Fasolato, C.; Capitani, F.; Postorino, P.; Fasolato, C.; Daniele, M.; Lupi, S.; Caminiti, R.
Classificazione: 1 Contributo su Rivista
Abstract: The intrinsic molecular polarity of a molecule, i.e. its dipole moment, seems to have an important role in the mixing process of an Ionic Liquid and a Molecular Liquid. In this work we report a complete study on the overall organization of a 1:1 binary mixture of Ethylammonium Nitrate and Ethylene Glycol by means of Wide Angle X-Ray Scattering, Raman Spectroscopy and Far Infrared Spectroscopy. The interpretation of all the experimental data was aided by a variety of computational models obtained via Classical Molecular Dynamics, ab initio Molecular Dynamics and DFT calculations. We observe that in the samples examined the Nitrate anion is strongly solvated by glycol molecules. This interaction has notable consequences on experimental observations.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300117 Collegamento a IRIS

2017
Water and hexane in an ionic liquid: Computational evidence of association under high pressure
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Autore/i: Mariani, A.; Caminiti, R.; Gontrani, L.
Classificazione: 1 Contributo su Rivista
Abstract: High pressures may strongly affect the mesoscopic structure of some ionic liquids. In particular, the so called sponge-like structure is gradually destroyed when an increasing pressure is applied. Here we show how a polar solute, an apolar solute or a mixture thereof behave in the ionic liquid trihexyl, tetradecylphosphonium bis (trifluoromethyl-sulfonyl) imide when the pressure is raised up to 10 kbar. Our calculations clearly show an association between molecules that would not interact in ordinary conditions.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300166 Collegamento a IRIS

2017
Inhomogeneity in Ethylammonium Nitrate-Acetonitrile Binary Mixtures: The Highest "low q Excess" Reported to Date
THE JOURNAL OF PHYSICAL CHEMISTRY LETTERS
Autore/i: Mariani, A.; Caminiti, R.; Ramondo, F.; Salvitti, G.; Mocci, F.; Gontrani, L.
Classificazione: 1 Contributo su Rivista
Abstract: The binary mixtures of the ionic liquid ethylammonium nitrate with acetonitrile have been studied by means of wide- and small-angle X-ray scattering and via two different computational methods, namely, classical molecular dynamics and DFT. The recently debated odd feature in the extreme low q region of some ionic liquid-based binary mixtures is linked to density fluctuations within the system. We show how the "low q excess" is due to some nanoscopic objects which are formed at certain compositions. These structures have different density with respect to the surrounding, thus generating the feature observed. Our results also show how the local arrangement is directly linked to the long-range structure. Moreover, we found once again a similarity in the physicochemical behavior of ethylammonium nitrate and water.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300157 Collegamento a IRIS

2017
Intriguing transport dynamics of ethylammonium nitrate-acetonitrile binary mixtures arising from nano-inhomogeneity
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Autore/i: Mariani, A.; Bonomo, M.; Wu, B.; Centrella, B.; Dini, D.; Castner, E. W.; Gontrani, L.
Classificazione: 1 Contributo su Rivista
Abstract: Binary mixtures of ethylammonium nitrate and acetonitrile show interesting properties that originate from the structural and dynamical nano-heterogeneity present in ionic liquids. These effects are most pronounced when the ionic liquid is the minority compound. In this study the transport properties of such mixtures are studied, including viscosity, self-diffusion and conductivity. The results strongly support the presence of structural inhomogeneity and show an interesting composition-dependent behaviour in the mixtures.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300155 Collegamento a IRIS

2016
Pressure-induced mesoscopic disorder in protic ionic liquids: First computational study
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
Autore/i: Mariani, A.; Caminiti, R.; Campetella, M.; Gontrani, L.
Classificazione: 1 Contributo su Rivista
Abstract: It has been recently shown that pressure may affect the mesoscopic heterogeneity in aprotic ionic liquids, owing to the long alkyl chain folding on itself. Here we explore protic ionic liquids, using classical molecular dynamics. These compounds have shorter and stiffer alkyl chains, harder to fold. We observed that high pressure affects the mesoscopic structure of the studied chemicals and, indeed, the effect may be ascribed to chain folding.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300152 Collegamento a IRIS

2016
Does High Pressure Induce Structural Reorganization in Linear Alcohols? A Computational Answer
CHEMPHYSCHEM
Autore/i: Mariani, A.; Ballirano, P.; Angiolari, F.; Caminiti, R.; Gontrani, L.
Classificazione: 1 Contributo su Rivista
Abstract: We present an exhaustive computational study on the effect of high pressure on normal alcohols with alkyl chains with lengths of three-to-eight carbon atoms. 1-Propanol, 1-butanol, 1-pentanol, 1-hexanol, 1-heptanol, and 1-octanol were studied by using classical molecular dynamics simulations and applying pressures in the range of 1 to 104 bar. The results of our calculations show that high-pressure values affect the structure significantly. In particular, we have observed a marked difference in behavior for alcohols with chain lengths below six and those with more than six or seven carbon atoms, with hexanol and heptanol being boundary cases. We have named the model with the most shrunk alkyl chains as the Asclepius form inspired by the Rod of Asclepius, the universally known symbol of medicine, in which a snake is coiled around a rod.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300165 Collegamento a IRIS

2016
Nanoscale Density Fluctuations in Ionic Liquid Binary Mixtures with Nonamphiphilic Compounds: First Experimental Evidence
JOURNAL OF PHYSICAL CHEMISTRY. B, CONDENSED MATTER, MATERIALS, SURFACES, INTERFACES & BIOPHYSICAL
Autore/i: Mariani, A.; Dattani, R.; Caminiti, R.; Gontrani, L.
Classificazione: 1 Contributo su Rivista
Abstract: A complex mesoscopic organization is observed in systems containing ethylammonium nitrate (EAN) and two nonamphiphilic compounds, using wide and small angle X-ray scattering and molecular dynamics simulations. The macroscopically homogeneous mixtures exhibit a separation where an ionic liquid-rich region is percolating a molecular liquid-rich one, but no unmixing is observed. This effect was already reported in EAN-alcohol mixtures, but the models proposed so far cannot explain this behavior for a nonamphiphilic compound.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300158 Collegamento a IRIS

2015
Structure of a binary mixture of ethylammonium nitrate and methanol
JOURNAL OF SOLUTION CHEMISTRY
Autore/i: Russina, O.; Mariani, A.; Caminiti, R.; Triolo, A.
Classificazione: 1 Contributo su Rivista
Abstract: Abstract We report a joint experimental (X-ray and neutron diffraction) and computational study on a binary mixture of ethylammonium nitrate (EAN), a protic ionic liquid, and methanol, the shortest alcohol. These two amphiphilic compounds are also characterized by the existence of an extended hydrogen bonding network in their neat states. We explore how these similar compounds structurally organize at the micro- and mesoscopic levels when mixed in a homogeneous state. The study demonstrates that the mixture is organized similarly to neat EAN, where the polar versus apolar dualism of the ionic liquid determines the segregation of alkyl tails into domains embedded into the ionic, percolating matrix. Methanol, due to the strong hydrogen bond with the nitrate anion, tends to intrude into this polar network, merging at EAN's polar-apolar interface. Further studies are proposed to rationalize the emerging mesoscopic density fluctuations that develop when approaching methanol-rich conditions.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300170 Collegamento a IRIS

2015
Structural organization in a methanol:ethylammonium nitrate (1:4) mixture: A joint X-ray/Neutron diffraction and computational study
JOURNAL OF MOLECULAR LIQUIDS
Autore/i: Mariani, A.; Russina, O.; Caminiti, R.; Triolo, A.
Classificazione: 1 Contributo su Rivista
Abstract: The molecular organization and dynamics of a binary mixture of a Protic Ionic Liquid (PIL), Ethylammonium Nitrate (EAN), and methanol (χEAN = 0.8) have been investigated by means of X-ray/Neutron Scattering with the support of classical Molecular Dynamics simulations. While at low EAN concentration, as some of us previously have reported (Russina, O. et al., 2014) [1], mesoscopic segregation occurs, in the present study the two components are fully miscible at mesoscopic level and no clustering is observed. The low alcohol's concentration does not lead to strong effects on the PIL's structure; on the other hand methanol's environment is substantially different than in the neat state. Enhanced interactions of EAN with alcohol lead to a loss of methanol-methanol correlations. Structural, dynamical and thermodynamical analysis on the computational model shows that the strongest and most probable hydrogen bond interactions of methanol occur with the nitrate anion, while its methyl group has an aliphatic interaction with EAN's terminal carbon and behaves like a pseudo hydrogen bond donor.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300169 Collegamento a IRIS

2015
Association in ethylammonium nitrate-dimethyl sulfoxide mixtures: First structural and dynamical evidences
JOURNAL OF NON-CRYSTALLINE SOLIDS
Autore/i: Russina, O.; Macchiagodena, M.; Kirchner, B.; Mariani, A.; Aoun, B.; Russina, M.; Caminiti, R.; Triolo, A.
Classificazione: 1 Contributo su Rivista
Abstract: Here we report the first structural and dynamic investigation on ethylammonium nitrate, a representative protic Ionic liquid, and dimethylsulfoxide. By using joined x/ray and neutron diffraction, we exploit the EPSR approach to extract structural information at atomistic level. EAN/DMSO turns out to be homogeneous at microscopic scales and indications for the existence of a structural leit motiv with stoichiometric composition 2DMSO:1EAN are found. Dielectric spectroscopy is used to access the relaxation map of the DMSO:EAN = 60:40 mixture. No crystallisation is detected and three relaxation processes could be characterised. Overall this study provides new indications of strict analogies between water and ethylammonium nitrate. (c) 2014 Elsevier B.V. All rights reserved.
Scheda della pubblicazione: https://iris.univpm.it/handle/11566/300171 Collegamento a IRIS




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