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Sharma A, Kumar V, Chakraborty S. Micro-Solvation of Propofol in Propylene Glycol-Water Binary Mixtures: Molecular Dynamics Simulation Studies. J Phys Chem B 2023; 127:11011-11022. [PMID: 37972382 DOI: 10.1021/acs.jpcb.3c04932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2023]
Abstract
The water microstructure around propofol plays a crucial role in controlling their solubility in the binary mixture. The unusual nature of such a water microstructure can influence both translational and reorientational dynamics, as well as the water hydrogen bond network near propofol. We have carried out all-atom molecular dynamics simulations of five different compositions of the propylene glycol (PG)/water binary mixture containing propofol (PFL) molecules to investigate the differential behavior of water microsolvation shells around propofol, which is likely to control the propofol solubility. It is evident from the simulation snapshots for various compositions that the PG at high molecular ratio favors the water cluster and extended chainlike network that percolates within the PG matrix, where the propofol is in the dispersed state. We estimated that the radial distribution function indicates higher ordered water microstructure around propofol for high PG content, as compared to the lower PG content in the PG/water mixture. So, the hydrophilic PG regulates the stability of the water micronetwork around propofol and its solubility in the binary mixture. We observed that the translational and rotational mobility of water belonging to the propofol microsolvation shell is hindered for high PG content and relaxed toward the low PG molecular ratio in the PG/water mixture. It has been noticed that the structural relaxation of the hydrogen bond formed between the propofol and the water molecules present in the propofol microsolvation shell for all five compositions is found to be slower for high PG content and becomes faster on the way to low PG content in the mixture. Simultaneously, we calculated the intermittent residence time correlation function of the water molecules belonging to the microsolvation shell around the propofol for five different compositions and found a faster short time decay followed up with long time components. Again, the origin of such long time decay is primarily from the structural relaxation of the microsolvation shell around the propofol, where the high PG content shows the slower structural relaxation that turns faster as the PG content approaches to the other end of the compositions. So, our studies showed that the slower structural relaxation of the microsolvation shell around propofol for a high PG molecular ratio in the PG/water mixture correlate well with the extensive ordering of the water microstructure and restricted water mobility and facilitates the dissolution process of propofol in the binary mixture.
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Affiliation(s)
- Anupama Sharma
- Department of Computational Sciences, School of Basic Sciences, Central University of Punjab, Bathinda 151401, India
| | - Vishal Kumar
- Department of Computational Sciences, School of Basic Sciences, Central University of Punjab, Bathinda 151401, India
| | - Sudip Chakraborty
- Department of Computational Sciences, School of Basic Sciences, Central University of Punjab, Bathinda 151401, India
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Zhang J, Wang F, Cao Z, Wang Q. New State-Diagram of Aqueous Solutions Unveiling Ionic Hydration, Antiplasticization, and Structural Heterogeneities in LiTFSI-H 2O. J Phys Chem B 2021; 125:13041-13048. [PMID: 34788045 DOI: 10.1021/acs.jpcb.1c08431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Here, we report a new state-diagram for aqueous solutions based on concentration-dependent glass-transition temperatures of concentrated and ice freeze-concentrated solutions. Different from the equilibrium phase diagram, this new state-diagram can provide comprehensive information about the hydration numbers of solutes, nonequilibrium vitrification/cold-crystallization, and vitrification/devitrification processes of aqueous solutions in three distinct concentration zones separated by two critical water-content points of only functions of the hydration number. Based on this new state-diagram, we observe the comparable hydration ability of LiTFSI to LiCl and an atypical concentration-dependent cold-crystallization behavior of the LiTFSI-H2O system. These results unveil the negligible hydration ability of TFSI- in a water-rich solution, characterize the antiplasticizing effect of water induced by the strengthened Li+-TFSI--H2O interaction when only hydration water and confined water are present, and confirm the increasing fraction of water-rich domains with the decrease in water content when the cation and anion become incompletely hydrated on average. These results highlight the novel water-content-mediated interactions among the anion, cation, and H2O for LiTFSI-H2O.
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Affiliation(s)
- Jinbing Zhang
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China.,Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Fengping Wang
- School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China
| | - Zexian Cao
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China.,Songshan Lake Materials Laboratory, Dongguan 523808, China
| | - Qiang Wang
- Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
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Cerveny S, Mallamace F, Swenson J, Vogel M, Xu L. Confined Water as Model of Supercooled Water. Chem Rev 2016; 116:7608-25. [PMID: 26940794 DOI: 10.1021/acs.chemrev.5b00609] [Citation(s) in RCA: 171] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Water in confined geometries has obvious relevance in biology, geology, and other areas where the material properties are strongly dependent on the amount and behavior of water in these types of materials. Another reason to restrict the size of water domains by different types of geometrical confinements has been the possibility to study the structural and dynamical behavior of water in the deeply supercooled regime (e.g., 150-230 K at ambient pressure), where bulk water immediately crystallizes to ice. In this paper we give a short review of studies with this particular goal. However, from these studies it is also clear that the interpretations of the experimental data are far from evident. Therefore, we present three main interpretations to explain the experimental data, and we discuss their advantages and disadvantages. Unfortunately, none of the proposed scenarios is able to predict all the observations for supercooled and glassy bulk water, indicating that either the structural and dynamical alterations of confined water are too severe to make predictions for bulk water or the differences in how the studied water has been prepared (applied cooling rate, resulting density of the water, etc.) are too large for direct and quantitative comparisons.
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Affiliation(s)
- Silvina Cerveny
- Centro de Física de Materiales (CFM CSIC/EHU) - Material Physics Centre (MPC) , Paseo Manuel de Lardizabal 5, 20018 San Sebastian, Spain.,Donostia International Physics Center , Paseo Manuel de Lardizabal 4, 20018 San Sebastián, Spain
| | - Francesco Mallamace
- Dipartimento di Fisica, Università di Messina , Vill. S. Agata, CP 55, I-98166 Messina, Italy
| | - Jan Swenson
- Department of Physics, Chalmers University of Technology , SE-412 96 Göteborg, Sweden
| | - Michael Vogel
- Institut für Festkörperphysik, Technische Universität Darmstadt , Hochschulstraße 6, 64289 Darmstadt, Germany
| | - Limei Xu
- International Centre for Quantum Materials and School of Physics, Peking University , , Beijing 100871, China.,Collaborative Innovation Center of Quantum Matter , Beijing 100871, China
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Elamin K, Jansson H, Swenson J. Dynamics of aqueous binary glass-formers confined in MCM-41. Phys Chem Chem Phys 2015; 17:12978-87. [PMID: 25913915 DOI: 10.1039/c5cp00751h] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Dielectric permittivity measurements were performed on water solutions of propylene glycol (PG) and propylene glycol monomethyl ether (PGME) confined in 21 Å pores of the silica matrix MCM-41 C10 in wide frequency (10(-2)-10(6) Hz) and temperature (130-250 K) ranges. The aim was to elucidate how the formation of large hydrogen bonded structural entities, found in bulk solutions of PGME, was affected by the confined geometry, and to make comparisons with the dynamic behavior of the PG-water system. For all solutions the measurements revealed four almost concentration independent relaxation processes. The intensity of the fastest process is low compared to the other relaxation processes and might be caused by both hydroxyl groups of the pore surfaces and by local motions of water and solute molecules. The second fastest process contains contributions from both the main water relaxation as well as the intrinsic β-relaxation of the solute molecules. The third fastest process is the viscosity related α-relaxation. Its concentration independency is very different compared to the findings for the corresponding bulk systems, particularly for the PGME-water system. The experimental data suggests that the surface interactions induce a micro-phase separation of the two liquids, resulting in a full molecular layer of water molecules coordinating to the hydrophilic hydroxyl groups on the surfaces of the silica pores. This, in turn, increases the geometrical confinement effect for the remaining solution even more and prevents the building up of the same type of larger structural entities in the PGME-water system as in the corresponding bulk solutions. The slowest process is mainly hidden in the high conductivity contribution at low frequencies, but its temperature dependence can be extracted for the PGME-water system. However, its origin is not fully clear, as will be discussed.
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Affiliation(s)
- Khalid Elamin
- Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden.
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Tu W, Wang Y, Li X, Zhang P, Tian Y, Jin S, Wang LM. Unveiling the dependence of glass transitions on mixing thermodynamics in miscible systems. Sci Rep 2015; 5:8500. [PMID: 25686751 PMCID: PMC4330544 DOI: 10.1038/srep08500] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Accepted: 01/22/2015] [Indexed: 11/18/2022] Open
Abstract
The dependence of the glass transition in mixtures on mixing thermodynamics is examined by focusing on enthalpy of mixing, ΔHmix with the change in sign (positive vs. negative) and magnitude (small vs. large). The effects of positive and negative ΔHmix are demonstrated based on two isomeric systems of o- vs. m- methoxymethylbenzene (MMB) and o- vs. m- dibromobenzene (DBB) with comparably small absolute ΔHmix. Two opposite composition dependences of the glass transition temperature, Tg, are observed with the MMB mixtures showing a distinct negative deviation from the ideal mixing rule and the DBB mixtures having a marginally positive deviation. The system of 1, 2- propanediamine (12PDA) vs. propylene glycol (PG) with large and negative ΔHmix is compared with the systems of small ΔHmix, and a considerably positive Tg shift is seen. Models involving the properties of pure components such as Tg, glass transition heat capacity increment, ΔCp, and density, ρ, do not interpret the observed Tg shifts in the systems. In contrast, a linear correlation is revealed between ΔHmix and maximum Tg shifts.
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Affiliation(s)
- Wenkang Tu
- State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China
| | - Yunxi Wang
- State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China
| | - Xin Li
- School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081 China
| | - Peng Zhang
- State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China
| | - Yongjun Tian
- State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China
| | - Shaohua Jin
- School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081 China
| | - Li-Min Wang
- State Key Lab of Metastable Materials Science and Technology, and College of Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China
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Swenson J, Elamin K, Chen G, Lohstroh W, Garcia Sakai V. Anomalous dynamics of aqueous solutions of di-propylene glycol methylether confined in MCM-41 by quasielastic neutron scattering. J Chem Phys 2014; 141:214501. [PMID: 25481146 DOI: 10.1063/1.4902250] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The molecular dynamics of solutions of di-propylene glycol methylether (2PGME) and H2O (or D2O) confined in 28 Å pores of MCM-41 have been studied by quasielastic neutron scattering and differential scanning calorimetry over the concentration range 0-90 wt.% water. This system is of particular interest due to its pronounced non-monotonic concentration dependent dynamics of 2PGME in the corresponding bulk system, showing the important role of hydrogen bonding for the dynamics. In this study we have elucidated how this non-monotonic concentration dependence is affected by the confined geometry. The results show that this behaviour is maintained in the confinement, but the slowest diffusive dynamics of 2PGME is now observed at a considerably higher water concentration; at 75 wt.% water in MCM-41 compared to 30 wt.% water in the corresponding bulk system. This difference can be explained by an improper mixing of the two confined liquids. The results suggest that water up to a concentration of about 20 wt.% is used to hydrate the hydrophilic hydroxyl surface groups of the silica pores, and that it is only at higher water contents the water becomes partly mixed with 2PGME. Hence, due to this partial micro-phase separation of the two liquids larger, and thereby slower relaxing, structural entities of hydrogen bonded water and 2PGME molecules can only be formed at higher water contents than in the bulk system. However, the Q-dependence is unchanged with confinement, showing that the nature of the molecular motions is preserved. Thus, there is no indication of localization of the dynamics at length scales of less than 20 Å. The dynamics of both water and 2PGME is strongly dominated by translational diffusion at a temperature of 280 K.
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Affiliation(s)
- Jan Swenson
- Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - Khalid Elamin
- Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - Guo Chen
- Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden
| | - Wiebke Lohstroh
- Heinz Maier-Leibnitz Zentrum (MLZ), Technische Universität München, Lichtenbergstr. 1, 85748 Garching, Germany
| | - Victoria Garcia Sakai
- ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX Oxfordshire, United Kingdom
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Elamin K, Björklund J, Nyhlén F, Yttergren M, Mårtensson L, Swenson J. Glass transition and relaxation dynamics of propylene glycol–water solutions confined in clay. J Chem Phys 2014; 141:034505. [DOI: 10.1063/1.4889742] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Tu W, Chen Z, Gao Y, Li Z, Zhang Y, Liu R, Tian Y, Wang LM. Glass transition and mixing thermodynamics of a binary eutectic system. Phys Chem Chem Phys 2014; 16:3586-92. [DOI: 10.1039/c3cp52868e] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Gong H, Chen Z, Bi D, Sun M, Tian Y, Wang LM. Unusual Dielectric Strength of Debye Relaxation in Monohydroxy Alcohols upon Mixing. J Phys Chem B 2012; 116:11482-7. [DOI: 10.1021/jp304110t] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hongxiang Gong
- State Key
Lab of Metastable Materials Science and Technology, and College of
Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China
| | - Zeming Chen
- State Key
Lab of Metastable Materials Science and Technology, and College of
Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China
| | - Dongyang Bi
- State Key
Lab of Metastable Materials Science and Technology, and College of
Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China
| | - Mingdao Sun
- State Key
Lab of Metastable Materials Science and Technology, and College of
Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China
| | - Yongjun Tian
- State Key
Lab of Metastable Materials Science and Technology, and College of
Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China
| | - Li-Min Wang
- State Key
Lab of Metastable Materials Science and Technology, and College of
Materials Science and Engineering, Yanshan University, Qinhuangdao, Hebei, 066004 China
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Elamin K, Sjöström J, Jansson H, Swenson J. Calorimetric and relaxation properties of xylitol-water mixtures. J Chem Phys 2012; 136:104508. [DOI: 10.1063/1.3692609] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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