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Zhu Y, Hou J, Gray DM, McDonald TO, Dumanli AG. Cation-induced morphological transitions and aggregation of thermoresponsive PNIPAM nanogels. Heliyon 2024; 10:e32184. [PMID: 39021897 PMCID: PMC11252870 DOI: 10.1016/j.heliyon.2024.e32184] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 05/09/2024] [Accepted: 05/29/2024] [Indexed: 07/20/2024] Open
Abstract
Poly(N-isopropylacrylamide) (PNIPAM) nanogels are promising responsive colloidal particles that can be used in pharmaceutical applications as drug carriers. This work investigates the temperature-dependent morphological changes and agglomeration of PNIPAM nanogels in the presence of mono- and multi-valent cationic electrolytes. We described the deswelling, flocculation, thermal reversibility behaviour and aggregated morphology of PNIPAM nanogels over a range of electrolyte concentrations and temperatures revealing the critical transition points from stable suspension to spontaneous agglomeration. We demonstrated that the flocculating ability and the rate of aggregate formation follow the order of deswelling behaviour. Transmission electron microscopy and atomic force microscopy analysis revealed the presence of a shell-like layer with varying density in the multivalent electrolyte solutions when compared to those in aqueous medium. We identified a concentration threshold of the thermally induced reversible aggregation/dispersion for the PNIPAM nanogels in the presence of Na+ and K+ ions at 10 mM, for Mg2+ and Ca2+ ions at 1 mM and for Al3+ ions at 0.1 mM concentrations. Such concentration thresholds indicated the effective destabilization of the electrolyte system with multivalency following the Schulze-Hardy rule. Our findings were supported by applying a Debye screening model that accounts for the shielding effect of multivalent cationic electrolytes on these nanogel systems. Our experiments and the models confirmed the compression of the electric double layer as the valency and ionic strength increased, except for Al3+ at higher concentrations which seemed to disrupt the electrical double layer and cause reversal of zeta potential. Our work highlights the significant impact the presence of multivalent cations can impose on the stability and morphology of nanogels, and this understanding will help in designing responsive nanogel systems based on PNIPAM nanogels.
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Affiliation(s)
- Yuchen Zhu
- Department of Materials, The University of Manchester, Oxford Rd, Manchester, M13 9PL, UK
- Henry Royce Institute, The University of Manchester, Oxford Rd, Manchester, M13 9PL, UK
| | - Jiaxin Hou
- Department of Materials, The University of Manchester, Oxford Rd, Manchester, M13 9PL, UK
- Henry Royce Institute, The University of Manchester, Oxford Rd, Manchester, M13 9PL, UK
| | - Dominic M. Gray
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, UK
| | - Tom O. McDonald
- Department of Materials, The University of Manchester, Oxford Rd, Manchester, M13 9PL, UK
- Henry Royce Institute, The University of Manchester, Oxford Rd, Manchester, M13 9PL, UK
- Department of Chemistry, University of Liverpool, Crown Street, Liverpool, L69 7ZD, UK
| | - Ahu Gümrah Dumanli
- Department of Materials, The University of Manchester, Oxford Rd, Manchester, M13 9PL, UK
- Henry Royce Institute, The University of Manchester, Oxford Rd, Manchester, M13 9PL, UK
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2
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Anomalous dielectric behaviors of electrolyte solutions confined in graphene oxide nanochannels. Sci Rep 2021; 11:18689. [PMID: 34548592 PMCID: PMC8455572 DOI: 10.1038/s41598-021-98326-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2021] [Accepted: 09/07/2021] [Indexed: 11/08/2022] Open
Abstract
Dielectric behavior of salt aqueous solutions with various concentration in pristine and oxide graphene nanochannels has been investigated by means of molecular dynamic simulations. The motivation in performing this integrated set of simulations was to provide deep insight into the interaction between the size of the enclosure and the oxidation degree of the membrane sheets on the dielectric properties. It was shown that the dielectric permittivity of both aqueous and NaCl solution in confined phase exhibits an anisotropic behavior. The in-plane component decreases with the increase of the concentration of NaCl solution while an increase of the out-of-plane dielectric is observed and these out-of-plane components exhibit a non-monotonous trend and thus exist a critical concentration of NaCl solution with 0.2 mol/L and 0.4 mol/L for both pristine and oxide graphene nanochannels, respectively. This peculiar dielectric behavior results from the addition of ions that significantly perturb the hydrogen bonding network of the confined system, and hence leading to a fluctuation of dipolar of water molecules and dielectric permittivity.
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3
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Tian J, Mao J, Zhang W, Yang X, Lin C, Cun M. Salinity‐ and Heat‐Tolerant VES (Viscoelastic Surfactant) Clean Fracturing Fluids Strengthened by a Hydrophobic Copolymer with Extremely Low Damage. ChemistrySelect 2021. [DOI: 10.1002/slct.202004274] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Jizhen Tian
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Chengdu 610500 P. R. China
| | - Jincheng Mao
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Chengdu 610500 P. R. China
| | - Wenlong Zhang
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Chengdu 610500 P. R. China
| | - Xiaojiang Yang
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Chengdu 610500 P. R. China
| | - Chong Lin
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Chengdu 610500 P. R. China
| | - Meng Cun
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University Chengdu 610500 P. R. China
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4
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Application of gemini viscoelastic surfactant with high salt in brine-based fracturing fluid. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2020.125838] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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5
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Zhu H, Hu B, Hu H, He W, Huang J, Li G. Tunable dielectric constant of water confined in graphene oxide nanochannels. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2020.115139] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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6
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Zhu H, Hu B, Hu H, Zhu Y, He W, Huang J, Li G. Influence of the oxidation rate on the dielectric properties of water confined in graphene bilayers. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2020.113995] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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7
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Application of a Zwitterionic Hydrophobic Associating Polymer with High Salt and Heat Tolerance in Brine-Based Fracturing Fluid. Polymers (Basel) 2019; 11:polym11122005. [PMID: 31817036 PMCID: PMC6960765 DOI: 10.3390/polym11122005] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Revised: 11/22/2019] [Accepted: 11/29/2019] [Indexed: 11/30/2022] Open
Abstract
ZID16PM, a zwitterionic hydrophobic associating polymer, has equivalent positive and negative charges and some hydrophobic monomers with twin-tailed long hydrophobic chains. It exhibits a great heat resistance and salt tolerance to the common salt in formation brine (MgCl2, CaCl2, NaCl, and KCl), which is attributed to its anti-polyelectrolyte effect and strong association force. High-salinity water (seawater or formation water) can be prepared as a fracturing fluid directly. In this paper, the formation water of the West Sichuan Gas Field is directly prepared into fracturing fluid with a concentration of 0.3% ZID16PM (Fluid-1), and the seawater of the Gulf of Mexico is directly prepared into fracturing fluid with a concentration of 0.3% ZID16PM (Fluid-2). Finally, rheological measurements, proppant suspension tests, and core matrix permeability damage rate tests for the Fluid-1 and Fluid-2 are conducted. Results show that after 120 min of shearing at 140 and 160 °C, respectively, the viscosity of Fluid-1 remains in the range of 50–85 mPa·s, and the viscosity of Fluid-2 remains in the range of 60–95 mPa·s. And the wastewater produced by an oilfield in Shaanxi, Xinjiang, and Jiangsu are also prepared into fracturing fluids with a concentration of 0.3% ZID16PM, the viscosity of these fracturing fluids can remain 32, 42, and 45 mPa·s, respectively, after 120 min of shearing at 160 °C. All results demonstrate that the polymer ZID16PM displays prominent performance in fracturing fluids.
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8
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Kumar P, Yashonath S. Ionic conductivity in aqueous electrolyte solutions: Insights from computer simulations. J Mol Liq 2019. [DOI: 10.1016/j.molliq.2018.12.090] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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9
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Chand A, Chettiyankandy P, Chowdhuri S. Behaviour of cis- and trans-N-methylformamide in liquid mixture: Dynamical properties at varying pressure and temperature, and ion solvation scenario. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.08.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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10
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Mao J, Tan H, Yang B, Zhang W, Yang X, Zhang Y, Zhang H. Novel Hydrophobic Associating Polymer with Good Salt Tolerance. Polymers (Basel) 2018; 10:E849. [PMID: 30960774 PMCID: PMC6403944 DOI: 10.3390/polym10080849] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 07/30/2018] [Indexed: 12/03/2022] Open
Abstract
A hydrophobic associating polymer named DiPHAM (acrylamide/sodium acrylamide-2-methylpropanesulfonic/sodium acrylate/N,N-di-n-dodecylacrylamide) with good salt tolerance was synthesized via photo-initiation polymerization. The critical association concentration (CAC) of DiPHAM was determined by viscosity changes to be 490 mg/L with different DiPHAM concentrations and particle sizes varied under such dynamic conditions. The influences of aqueous metal ions with different charges on its aqueous solution were investigated by measuring apparent viscosity, viscoelasticity, thixotropy, rheology, and particle size, and by SEM observation. The apparent viscosity of the DiPHAM solution was affected by metal ions to some extent, but the viscosity of the polymer can be still maintained at 55 mPa·s under 20 × 10⁴ mg/L NaCl. Divalent metal ions show greater impact on DiPHAM aqueous solutions, but the polymer solutions showed resistance to the changes caused in viscosity, structure, and viscoelasticity by Ca2+ and Mg2+ ions. The salt tolerance of DiPHAM is due to the combination of hydrophobic association, the electrostatic shield, and double layer compression of the hydration shell. Increasing the ion concentration enhances the dehydration and further compresses the hydration shell, making the non-structural viscosity decrease, even "salting out". Measurements of rheological properties showed that DiPHAM solutions could maintain a relatively high viscosity (0.6%-71 mPa·s/0.3%-50 mPa·s) after 120 min of continuous shearing (170 s-1) at 140 °C. Under high-salinity (5000 mg/L Ca2+/3000 mg/L Mg2+) conditions, the solution with 0.6 wt% DiPHAM still maintained a high viscosity (50 mPa·s/70 mPa·s) after continuously shearing for 120 min at 120 °C and 170 s-1. The good salt tolerance of DiPHAM can lead to a variety of applications, including in fracturing fluids for enhanced oil recovery (EOR) and in sewage treatment.
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Affiliation(s)
- Jincheng Mao
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China.
| | - Hongzhong Tan
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China.
| | - Bo Yang
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China.
| | - Wenlong Zhang
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China.
| | - Xiaojiang Yang
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China.
| | - Yang Zhang
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China.
| | - Heng Zhang
- State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, China.
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11
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Chand A, Chowdhuri S. A comparative study of hydrogen bonding structure and dynamics in aqueous urea solution of amides with varying hydrophobicity: Effect of addition of trimethylamine N -oxide (TMAO). J Mol Liq 2017. [DOI: 10.1016/j.molliq.2017.06.121] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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12
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Prasad S, Chakravarty C. Solvation of LiCl in model liquids with high to low hydrogen bond strengths. J Chem Phys 2017. [DOI: 10.1063/1.4982828] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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13
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Turk M, Walters M, Roy D. Experimental considerations for using electrochemical impedance spectroscopy to study chemical mechanical planarization systems. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2016.12.062] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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14
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Chand A, Chowdhuri S. Behaviour of aqueous N-methylacetamide solution in presence of ethanol and 2,2,2 tri-fluoroethanol: Hydrogen bonding structure and dynamics. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2016.10.129] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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15
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CHAND APRAMITA, CHOWDHURI SNEHASIS. Effects of dimethyl sulfoxide on the hydrogen bonding structure and dynamics of aqueous N-methylacetamide solution. J CHEM SCI 2016. [DOI: 10.1007/s12039-016-1092-2] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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16
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Effects of methanol on the hydrogen bonding structure and dynamics in aqueous N-methylacetamide solution. J Mol Liq 2014. [DOI: 10.1016/j.molliq.2014.01.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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17
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Pattanayak SK, Chettiyankandy P, Chowdhuri S. Effects of co-solutes on the hydrogen bonding structure and dynamics in aqueous N-methylacetamide solution: a molecular dynamics simulations study. Mol Phys 2014. [DOI: 10.1080/00268976.2014.916822] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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18
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Garbacz P, Price WS. 1H NMR Diffusion Studies of Water Self-Diffusion in Supercooled Aqueous Sodium Chloride Solutions. J Phys Chem A 2014; 118:3307-12. [DOI: 10.1021/jp501472s] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Piotr Garbacz
- Faculty
of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
- Nanoscale
Organisation and Dynamics Group, University of Western Sydney, Penrith, NSW 2751, Australia
| | - William S. Price
- Nanoscale
Organisation and Dynamics Group, University of Western Sydney, Penrith, NSW 2751, Australia
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19
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Pressure and temperature dependence on the hydrogen bonding and dynamics of ammonium ion in liquid water: A molecular dynamics simulations study. J Mol Liq 2013. [DOI: 10.1016/j.molliq.2013.05.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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20
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Pressure effects on the dynamics of ions and solvent molecules in liquid methanol under ambient and cold conditions: Importance of solvent's H-bonding network. J Mol Liq 2013. [DOI: 10.1016/j.molliq.2013.01.014] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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21
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Galamba N. On the Effects of Temperature, Pressure, and Dissolved Salts on the Hydrogen-Bond Network of Water. J Phys Chem B 2013; 117:589-601. [DOI: 10.1021/jp309312q] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- N. Galamba
- Grupo de Física-Matemática
da Universidade de Lisboa, Av. Prof. Gama
Pinto 2, 1649-003
Lisboa, Portugal
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22
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Das D, Dey J, Chandra AK, Thapa U, Ismail K. Aggregation behavior of sodium dioctylsulfosuccinate in aqueous ethylene glycol medium. A case of hydrogen bonding between surfactant and solvent and its manifestation in the surface tension isotherm. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2012; 28:15762-15769. [PMID: 23072621 DOI: 10.1021/la302876z] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The dependence of critical micelle concentration (cmc) of sodium dioctylsulfosuccinate (AOT) on the amount of ethylene glycol (EG) in water + EG medium was reported to be unusual and different from that of other surfactants to the extent that the cmc of AOT in EG is lower than in water. It is yet to be understood why AOT behaves so in water + EG medium, although AOT is known to have some special properties. Hence in the present study cmc of AOT in water + EG medium in the range from 0 to 100% (by weight) EG is measured by using surface tension and fluorescence emission methods. In contrast to what was reported, this study revealed that with respect to EG amount the cmc of AOT follows the general trend and AOT has higher cmc in EG than in water. On the other hand, it was surprisingly found that a break in the surface tension isotherm occurs in the premicellar region when the amount of EG exceeds 50% rendering a bisigmoidal shape to the surface tension isotherm. UV spectral study showed that AOT and EG undergo hydrogen bonding in the premicellar region when the EG amount is ≥50% and this hydrogen bonding becomes less on adding NaCl. The density functional theory calculations also showed formation of hydrogen bonds between EG and AOT through the sulfonate group of AOT providing thereby support to the experimental findings. The calculations predicted a highly stable AOT-EG-H(2)O trimer complex with a binding energy of -37.93 kcal mol(-1). The present system is an example, which is first of its kind, of a case where hydrogen bonding with surfactant and solvent molecules results in a surface tension break.
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Affiliation(s)
- D Das
- Department of Chemistry, North-Eastern Hill University, Shillong, India
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23
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Varanasi SR, Kumar P, Subramanian Y. Effect of pressure on the ionic conductivity of Li+ and Cl− ions in water. J Chem Phys 2012; 137:144506. [DOI: 10.1063/1.4756909] [Citation(s) in RCA: 5] [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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24
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Rana MK, Chandra A. Solvation of fullerene and fulleride ion in liquid ammonia: Structure and dynamics of the solvation shells. J Chem Phys 2012; 137:134501. [DOI: 10.1063/1.4754852] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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25
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26
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Pattanayak SK, Chowdhuri S. A molecular dynamics simulations study on the behavior of liquid N-methylacetamide in presence of NaCl: Structure, dynamics and H-bond properties. J Mol Liq 2012. [DOI: 10.1016/j.molliq.2012.05.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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27
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Chowdhuri S, Pattanayak SK. Pressure dependence on the single-particle dynamics and hydrogen-bond structural relaxation of water–DMSO mixtures under ambient and cold conditions. Mol Phys 2012. [DOI: 10.1080/00268976.2012.707692] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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28
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MALLIK BHABANIS, CHANDRA AMALENDU. Hydrogen bond dynamics and vibrational spectral diffusion in aqueous solution of acetone: A first principles molecular dynamics study#. J CHEM SCI 2012. [DOI: 10.1007/s12039-012-0219-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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29
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Pattanayak SK, Chowdhuri S. Effect of Water on Solvation Structure and Dynamics of Ions in the Peptide Bond Environment: Importance of Hydrogen Bonding and Dynamics of the Solvents. J Phys Chem B 2011; 115:13241-52. [DOI: 10.1021/jp206027e] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Snehasis Chowdhuri
- School of Basic Sciences, Indian Institute of Technology, Bhubaneswar 751013, India
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30
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31
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Bouazizi S, Nasr S. Self-diffusion coefficients and orientational correlation times in aqueous NaCl solutions. J Mol Liq 2011. [DOI: 10.1016/j.molliq.2011.06.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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32
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Chakraborty D, Chandra A. Diffusion of ions in supercritical water: Dependence on ion size and solvent density and roles of voids and necks. J Mol Liq 2011. [DOI: 10.1016/j.molliq.2011.05.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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33
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Varanasi SR, Kumar P, Masia M, Demontis P, Suffritti GB, Yashonath S. A molecular dynamics study and molecular level explanation of pressure dependence of ionic conductivity of potassium chloride in water. Phys Chem Chem Phys 2011; 13:10877-84. [PMID: 21589981 DOI: 10.1039/c1cp00026h] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Experimental ionic conductivity of different alkali ions in water shows markedly different dependences on pressure. Existing theories such as that of Hubbard-Onsager are unable to explain these dependences on pressure of the ionic conductivity for all ions. We report molecular dynamics investigation of potassium chloride solution at low dilution in water at several pressures between 1 bar and 2 kbar. Two different potential models have been employed. One of the models successfully reproduces the experimentally observed trend in ionic conductivity of K(+) ions in water over the 0.001-2 kbar range. We also propose a theoretical explanation, albeit at a qualitative level, to account for the dependence of ionic conductivity on pressure in terms of the previously studied Levitation Effect. It also provides a microscopic picture in terms of the pore network in liquid water.
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Affiliation(s)
- Srinivasa R Varanasi
- Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, India
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34
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Gupta R, Chandra A. Nonideality in diffusion of ionic and neutral solutes and hydrogen bond dynamics in dimethyl sulfoxide-chloroform mixtures of varying composition. J Comput Chem 2011; 32:2679-89. [DOI: 10.1002/jcc.21849] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2010] [Revised: 04/14/2011] [Accepted: 05/10/2011] [Indexed: 12/11/2022]
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35
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Pattanayak SK, Prashar N, Chowdhuri S. Effect of temperature and pressure on the structure, dynamics, and hydrogen bond properties of liquid N-methylacetamide: A molecular dynamics study. J Chem Phys 2011; 134:154506. [DOI: 10.1063/1.3578467] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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36
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Gebauer JS, Treuel L. Influence of individual ionic components on the agglomeration kinetics of silver nanoparticles. J Colloid Interface Sci 2010; 354:546-54. [PMID: 21146829 DOI: 10.1016/j.jcis.2010.11.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 10/25/2010] [Accepted: 11/09/2010] [Indexed: 10/18/2022]
Abstract
The precise characteristic of the agglomeration behavior of colloidal suspensions is of paramount interest to many current studies in nanoscience. This work seeks to elucidate the influence that differently charged salts have on the agglomeration state of a Lee-Meisel-type silver colloid. Moreover, we investigate the influence of the chemical nature of individual ions on their potential to induce agglomeration. Raman spectroscopy and surface-enhanced Raman spectroscopy are used to give insights into mechanistic aspects of the agglomeration process and to assess the differences in the influence of different salts on the agglomeration behavior. Finally, we demonstrate the potential of the measurement procedure used in this work to determine the elementary charge on colloidal NPs.
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Affiliation(s)
- J S Gebauer
- Institute for Physical Chemistry and Centre for Water and Environmental Research, University of Duisburg-Essen, Universitaetsstrasse 5-7, 45117 Essen, Germany
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37
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Probing the Equilibrium Size and Hydrogen Bonding Structure in Aqueous Aerosol Droplets. ACTA ACUST UNITED AC 2010. [DOI: 10.1524/zpch.2010.6147] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
Comparative measurements on two or more optically trapped aerosol droplets can allow the hygroscopic properties of aerosol to be investigated in exquisite detail. In this paper we consider two methods for assessing the dependence on relative humidity of the water activity and solute concentration in the condensed phase. We demonstrate in this paper that using a control droplet as a microprobe of relative humidity in the vicinity of a second droplet of interest can allow the RH to be determined with an accuracy of between 0.01 to 0.1 %. Not only is such a probe highly responsive, but the accuracy of the RH determination improves with increase in GF or RH, counter to the performance of macroscopic RH probes. We also demonstrate that spontaneous Raman scattering recorded from excitation of the OH stretching vibration in supersaturated solution droplets of sodium chloride shows the considerable perturbation induced by the chloride ion on the hydrogen bonding network. Chloride is recognised as a hydrogen bonding structure breaker and these observations are shown to be consistent with measurements on more dilute solutions.
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Del Rizzo PA, Couture JF, Dirk LMA, Strunk BS, Roiko MS, Brunzelle JS, Houtz RL, Trievel RC. SET7/9 catalytic mutants reveal the role of active site water molecules in lysine multiple methylation. J Biol Chem 2010; 285:31849-58. [PMID: 20675860 DOI: 10.1074/jbc.m110.114587] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
SET domain lysine methyltransferases (KMTs) methylate specific lysine residues in histone and non-histone substrates. These enzymes also display product specificity by catalyzing distinct degrees of methylation of the lysine ε-amino group. To elucidate the molecular mechanism underlying this specificity, we have characterized the Y245A and Y305F mutants of the human KMT SET7/9 (also known as KMT7) that alter its product specificity from a monomethyltransferase to a di- and a trimethyltransferase, respectively. Crystal structures of these mutants in complex with peptides bearing unmodified, mono-, di-, and trimethylated lysines illustrate the roles of active site water molecules in aligning the lysine ε-amino group for methyl transfer with S-adenosylmethionine. Displacement or dissociation of these solvent molecules enlarges the diameter of the active site, accommodating the increasing size of the methylated ε-amino group during successive methyl transfer reactions. Together, these results furnish new insights into the roles of active site water molecules in modulating lysine multiple methylation by SET domain KMTs and provide the first molecular snapshots of the mono-, di-, and trimethyl transfer reactions catalyzed by these enzymes.
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Affiliation(s)
- Paul A Del Rizzo
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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Holzmann J, Appelhagen A, Ludwig R. Correlation of Static and Dynamic Heterogeneities in Supercooled Water by Means of Molecular Dynamics Simulations. ACTA ACUST UNITED AC 2009. [DOI: 10.1524/zpch.2009.6065] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Abstract
The unusual increase of diffusivity of supercooled water upon compression seems to be related to the existence of at least two major distinct local structural forms: a "low-density" structure, exhibiting an almost perfect tetrahedral hydrogen bonding network, and a "high-density" structure, characterized by defects in this network. The structural changes can be measured by the "tetrahedricity parameter", describing the deviation from the ideal tetrahedron. In this paper we show that the anomalous diffusion behavior upon compression cannot only be related to the structural heterogeneities but also to dynamical heterogeneities occuring in supercooled liquid water. This is shown for translational heterogeneities which decrease with temperature and pressure. Both, static and dynamic heterogeneities can be correlated. They are substantial at low temperatures and moderate pressures and diminish with increasing temperature and pressure, respectively. Our results are based on molecular dynamics simulations of the TIP4P-Ew water model [1].
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Pradhan T, Gazi HAR, Biswas R. Excited state intramolecular charge transfer reaction in nonaqueous electrolyte solutions: Temperature dependence. J Chem Phys 2009; 131:054507. [DOI: 10.1063/1.3196239] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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41
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Goujon F, Bonal C, Limoges B, Malfreyt P. Molecular simulations of grafted metal-chelating monolayers: methodology, structure and energy. Mol Phys 2008. [DOI: 10.1080/00268970802235557] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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42
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Gupta R, Chandra A. Single particle and pair dynamics in water–formic acid mixtures containing ionic and neutral solutes: Nonideality in dynamical properties. J Chem Phys 2008; 128:184506. [DOI: 10.1063/1.2913058] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
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Holzmann J, Ludwig R, Geiger A, Paschek D. Pressure and Salt Effects in Simulated Water: Two Sides of the Same Coin? Angew Chem Int Ed Engl 2007; 46:8907-11. [DOI: 10.1002/anie.200702736] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Holzmann J, Ludwig R, Geiger A, Paschek D. Druck- und Salzeffekte in simuliertem Wasser: zwei Seiten einer Medaille? Angew Chem Int Ed Engl 2007. [DOI: 10.1002/ange.200702736] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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45
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Gupta R, Chandra A. Nonideality in diffusion of ionic and hydrophobic solutes and pair dynamics in water-acetone mixtures of varying composition. J Chem Phys 2007; 127:024503. [PMID: 17640133 DOI: 10.1063/1.2751192] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We have performed a series of molecular dynamics simulations of water-acetone mixtures containing either an ionic solute or a neutral hydrophobic solute to study the extent of nonideality in the dynamics of these solutes with variation of composition of the mixtures. The diffusion coefficients of the charged solutes, both cationic and anionic, are found to change nonmonotonically with the composition of the mixtures showing strong nonideality of their dynamics. Also, the extent of nonideality in the diffusion of these charged solutes is found to be similar to the nonideality that is observed for the diffusion and orientational relaxation of water and acetone molecules in these mixtures which show a somewhat similar changes in the solvation characteristics of charged and dipolar solutes with changes of composition of water-acetone mixtures. The diffusion of the hydrophobic solute, however, shows a monotonic increase with increase of acetone concentration showing its different solvation characteristics as compared to the charged and dipolar solutes. The links between the nonideality in diffusion and solvation structures are further confirmed through calculations of the relevant solute-solvent and solvent-solvent radial distribution functions for both ionic and hydrophobic solutes. We have also calculated various pair dynamical properties such as the relaxation of water-water and acetone-water hydrogen bonds and residence dynamics of water molecules in water and acetone hydration shells. The lifetimes of both water-water and acetone-water hydrogen bonds and also the residence times of water molecules are found to increase steadily with increase in acetone concentration. No maximum or minimum was found in the composition dependence of these pair dynamical quantities. The lifetimes of water-water hydrogen bonds are always found to be longer than that of acetone-water hydrogen bonds in these mixtures. The residence times of water molecules are also found to follow a similar trend.
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Affiliation(s)
- Rini Gupta
- Department of Chemistry, Indian Institute of Technology, Kanpur, India 208016
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46
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Ghoufi A, Malfreyt P. Calculation of the absolute thermodynamic properties of association of host-guest systems from the intermolecular potential of mean force. J Chem Phys 2006; 125:224503. [PMID: 17176145 DOI: 10.1063/1.2402165] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The authors report calculations of the intermolecular potential of mean force (PMF) in the case of the host-guest interaction. The host-guest system is defined by a water soluble calixarene and a cation. With an organic cation such as the tetramethylammonium cation, the calixarene forms an insertion complex, whereas with the Lanthane cation, the supramolecular assembly is an outer-sphere complex. The authors apply a modified free energy perturbation method and the force constraint technique to establish the PMF profiles as a function of the separation distance between the host and guest. They use the PMF profile for the calculation of the absolute thermodynamic properties of association that they compare to the experimental values previously determined. They finish by giving some structural features of the insertion and outer-sphere complexes at the Gibbs free energy minimum.
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Affiliation(s)
- Aziz Ghoufi
- Laboratoire de Thermodynamique des Solutions et des Polymères, UMR CNRS 6003, Université Blaise Pascal, 63177 Aubière Cedex, France
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Mudi A, Chakravarty C. Effect of Ionic Solutes on the Hydrogen Bond Network Dynamics of Water: Power Spectral Analysis of Aqueous NaCl Solutions. J Phys Chem B 2006; 110:8422-31. [PMID: 16623528 DOI: 10.1021/jp056003l] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
To understand the modifications of the hydrogen bond network of water by ionic solutes, power spectra as well as static distributions of the potential energies of tagged solvent molecules and solute ions have been computed from molecular dynamics simulations of aqueous NaCl solutions. The key power spectral features of interest are the presence of high-frequency peaks due to localized vibrational modes, the existence of a multiple time scale or 1/falpha frequency regime characteristic of networked liquids, and the frequency of crossover from 1/falpha type behavior to white noise. Hydrophilic solutes, such as the sodium cation and the chloride anion, are shown to mirror the multiple time scale behavior of the hydrogen bond network fluctuations, unlike hydrophobic solutes which display essentially white noise spectra. While the power spectra associated with tagged H2O molecules are not very sensitive to concentration in the intermediate frequency 1/falpha regime, the crossover to white noise is shifted to lower frequencies on going from pure solvent to aqueous alkali halide solutions. This suggests that new and relatively slow time scales enter the picture, possibly associated with processes such as migration of water molecules from the hydration shell to the bulk or conversion of contact ion pairs into solvent-separated ion pairs which translate into variations in equilibrium transport properties of salt solutions with concentration. For anions, cations, and solvent molecules, the trends in the alpha exponents of the multiple time scale region and the self-diffusivities are found to be strongly correlated.
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Affiliation(s)
- Anirban Mudi
- Department of Chemistry, Indian Institute of Technology-Delhi, New Delhi 110016, India
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Ghorai PK, Yashonath S, Lynden-Bell RM. Size-Dependent Maximum in Ion Conductivity: The Levitation Effect Provides an Alternative Explanation. J Phys Chem B 2005; 109:8120-4. [PMID: 16851949 DOI: 10.1021/jp044605j] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We propose an alternative explanation of the size-dependent maximum in ion mobility in water in terms of the levitation effect, which accounts for the observed size-dependent maximum in the mobility of guest diffusion in porous media. In this explanation, the size at which the maximum occurs is related to the structure of the void space of the water; at the mobility maximum, the diffusant passes smoothly through necks connecting voids, and its potential energy shows minimum fluctuations. Molecular dynamics simulations of charged spheres of varying sizes are used to support this hypothesis. As in the levitation effect, the friction coefficient, the potential energy fluctuations, and the activation energy are found to be minima for particles with maximum self diffusivities similar to the guest diffusion in zeolites. Wavelength-dependent self diffusivities indicate a monotonic and oscillatory dependence, respectively, on wavenumber k for anomalous (AR) and linear regimes (LR). These are associated with single and biexponential decay of the incoherent intermediate scattering function.
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Affiliation(s)
- Pradip Kr Ghorai
- Solid State and Structural Chemistry Unit and Center for Condensed Matter Theory, Indian Institute of Science, Bangalore, India 560 012
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Guàrdia E, Martí J, García-Tarrés L, Laria D. A molecular dynamics simulation study of hydrogen bonding in aqueous ionic solutions. J Mol Liq 2005. [DOI: 10.1016/j.molliq.2004.08.004] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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50
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Hydrogen bonded structure of water and aqueous solutions of sodium halides: a Raman spectroscopic study. J Mol Struct 2004. [DOI: 10.1016/j.molstruc.2004.07.016] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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