Biomimetic design of protic lipidic ionic liquids with enhanced fluidity

Polyhedral oligomeric silsesquioxanes (POSSs), Am-POSS(x,y), prepared by hydrolytic condensation, contains two types of ammonium side-chain groups, where the numbering of x and y represents the type of ammonium ions in the POSS structure, corresponding to primary (1), secondary (2), tertiary (3), and quaternary (4) ammonium ions. Mixtures of the two starting materials selected from organotrialkoxysilanes containing primary, secondary, and tertiary amines and a quaternary ammonium salt [(RO)3Si(CH2)3R′, R = CH3 or CH2CH3, R′ = NH2, NHCH3, N(CH3)2, and N(CH3)3Cl] were dissolved in dimethyl sulfoxide (DMSO). The hydrolytic condensation was performed in the presence of bis(trifluoromethansulfonyl)imide (HNTf2) and water. All Am-POSS(x,y) structures consisted of a cage-type octamer (T8-POSS), as confirmed by 29Si NMR spectrometry and matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) analyses indicated that Am-POSS(1,3), Am-POSS(1,4), and Am-POSS(2,4) had amorphous structures. These POSSs have two or three differences in the number of methyl groups between the two types of ammonium side-chains. Conversely, Am-POSS(1,2), Am-POSS(2,3), and Am-POSS(3,4) had crystalline structures. The difference in the number of methyl groups between the two types of ammonium side-chains in these POSSs is only one. Therefore, the crystalline-amorphous structure of Am-POSS(x,y) is controlled by the side-chain group combinations. Furthermore, Am-POSS(1,3), Am-POSS(1,4), and Am-POSS(2,4) are protic ionic liquids with relatively low flow temperatures.

Download Full-text

Ion conformation and orientational order in a dicationic ionic liquid crystal studied by solid-state nuclear magnetic resonance spectroscopy

Scientific Reports ◽

10.1038/s41598-021-85021-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Debashis Majhi ◽

Sergey V. Dvinskikh

Keyword(s):

Ionic Liquid ◽

Ionic Liquids ◽

Liquid Crystals ◽

Bond Order ◽

Van Der Waals ◽

Orientational Order ◽

Smectic Phase ◽

Side Chains ◽

Dicationic Ionic Liquid ◽

Ionic Liquid Crystals

AbstractIonic liquids crystals belong to a special class of ionic liquids that exhibit thermotropic liquid-crystalline behavior. Recently, dicationic ionic liquid crystals have been reported with a cation containing two single-charged ions covalently linked by a spacer. In ionic liquid crystals, electrostatic and hydrogen bonding interactions in ionic sublayer and van der Waals interaction in hydrophobic domains are the main forces contributing to the mesophase stabilization and determining the molecular orientational order and conformation. How these properties in dicationic materials are compared to those in conventional monocationic analogs? We address this question using a combination of advanced NMR methods and DFT analysis. Dicationic salt 3,3′-(1,6-hexanediyl)bis(1-dodecylimidazolium)dibromide was studied. Local bond order parameters of flexible alkyl side chains, linker chain, and alignment of rigid polar groups were analyzed. The dynamic spacer effectively “decouples” the motion of two ionic moieties. Hence, local order and alignment in dicationic mesophase were similar to those in analogous single-chain monocationic salts. Bond order parameters in the side chains in the dicationic smectic phase were found consistently lower compared to double-chain monocationic analogs, suggesting decreasing contribution of van der Waals forces. Overall dication reorientation in the smectic phase was characterized by low values of orientational order parameter S. With increased interaction energy in the polar domain the layered structure is stabilized despite less ordered dications. The results emphasized the trends in the orientational order in ionic liquid crystals and contributed to a better understanding of interparticle interactions driving smectic assembly in this and analogous ionic mesogens.

Download Full-text

DFT Study on the Chemical Absorption Mechanism of CO2 in Diamino Protic Ionic Liquids

The Journal of Physical Chemistry B ◽

10.1021/acs.jpcb.0c08500 ◽

2021 ◽

Vol 125 (5) ◽

pp. 1416-1428

Author(s):

Jing Ma ◽

Yutong Wang ◽

Xueqing Yang ◽

Mingxuan Zhu ◽

Baohe Wang

Keyword(s):

Ionic Liquids ◽

Dft Study ◽

Protic Ionic Liquids ◽

Absorption Mechanism ◽

Chemical Absorption

Download Full-text

The Synthesis of Poly(Vinyl Alcohol) Grafted with Fluorinated Protic Ionic Liquids Containing Sulfo Functional Groups

Molecules ◽

10.3390/molecules26144158 ◽

2021 ◽

Vol 26 (14) ◽

pp. 4158

Author(s):

Patrycja Glińska ◽

Andrzej Wolan ◽

Wojciech Kujawski ◽

Edyta Rynkowska ◽

Joanna Kujawa

Keyword(s):

Ionic Liquids ◽

Vinyl Alcohol ◽

Proton Exchange ◽

Polymer Materials ◽

Polymerization Reaction ◽

Poly Vinyl Alcohol ◽

Hydroxyl Groups ◽

Protic Ionic Liquids ◽

Synthesis Route ◽

Sulfo Groups

There has been an ongoing need to develop polymer materials with increased performance as proton exchange membranes (PEMs) for middle- and high-temperature fuel cells. Poly(vinyl alcohol) (PVA) is a highly hydrophilic and chemically stable polymer bearing hydroxyl groups, which can be further altered. Protic ionic liquids (proticILs) have been found to be an effective modifying polymer agent used as a proton carrier providing PEMs’ desirable proton conductivity at high temperatures and under anhydrous conditions. In this study, the novel synthesis route of PVA grafted with fluorinated protic ionic liquids bearing sulfo groups (–SO3H) was elaborated. The polymer functionalization with fluorinated proticILs was achieved by the following approaches: (i) the PVA acylation and subsequent reaction with fluorinated sultones and (ii) free-radical polymerization reaction of vinyl acetate derivatives modified with 1-methylimidazole and sultones. These modifications resulted in the PVA being chemically modified with ionic liquids of protic character. The successfully grafted PVA has been characterized using 1H, 19F, and 13C-NMR and FTIR-ATR. The presented synthesis route is a novel approach to PVA functionalization with imidazole-based fluorinated ionic liquids with sulfo groups.

Download Full-text

Development of a robust soft-SAFT model for protic ionic liquids using new high-pressure density data

Fluid Phase Equilibria ◽

10.1016/j.fluid.2021.113036 ◽

2021 ◽

pp. 113036

Author(s):

Emanuel A. Crespo ◽

Liliana P. Silva ◽

Cristina I.P. Correia ◽

Mónia A.R. Martins ◽

Ramesh L. Gardas ◽

...

Keyword(s):

High Pressure ◽

Ionic Liquids ◽

Protic Ionic Liquids ◽

Density Data

Download Full-text

Insights into the translational and rotational dynamics of cations and anions in protic ionic liquids by means of NMR fast-field-cycling relaxometry

Physical Chemistry Chemical Physics ◽

10.1039/d0cp05440b ◽

2021 ◽

Vol 23 (4) ◽

pp. 2663-2675

Author(s):

Viviane Overbeck ◽

Henning Schröder ◽

Anne-Marie Bonsa ◽

Klaus Neymeyr ◽

Ralf Ludwig

Keyword(s):

Ionic Liquids ◽

Rotational Dynamics ◽

Protic Ionic Liquids ◽

Field Cycling ◽

Fast Field ◽

Hydrogen Bonded

NMR Fast-Field-Cycling (FFC) relaxometry provides important information about translational and rotational dynamics of hydrogen bonded protic ionic liquids (PILs).

Download Full-text