scholarly journals Side chain length impacting thermal transitions and water uptake of acrylate–maleimide copolymers with pendent catechols

RSC Advances ◽  
2017 ◽  
Vol 7 (77) ◽  
pp. 49114-49118 ◽  
Author(s):  
M. A. Bartucci ◽  
E. Napadensky ◽  
J. L. Lenhart ◽  
J. A. Orlicki
Keyword(s):  
Chain Length ◽  
Water Uptake ◽  
Side Chain ◽  
Moisture Uptake ◽  
Thermal Transitions ◽  
Side Chain Length ◽  
Alkyl Acrylate

Significant moisture uptake was observed for a family of catechol side-chain poly(alkyl acrylate-maleimide)s (PAMs) intended to probe the effects of Tg and polarity.

scholarly journals Dissipative Particle Dynamics Modeling of Polyelectrolyte Membrane–Water Interfaces

Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 907
Author(s):  
Soumyadipta Sengupta ◽  
Alexey Lyulin
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Chain Length ◽  
Water Uptake ◽  
Water Cluster ◽  
Dissipative Particle Dynamics ◽  
Particle Dynamics ◽  
Side Chain ◽  
Side Chain Length ◽  
Polyelectrolyte Membrane

Previous experiments of water vapor penetration into polyelectrolyte membrane (PEM) thin films have indicated the influence of the water concentration gradient and polymer chemistry on the interface evolution, which will eventually affect the efficiency of the fuel cell operation. Moreover, PEMs of different side chains have shown differences in water cluster structure and diffusion. The evolution of the interface between water and polyelectrolyte membranes (PEMs), which are used in fuel cells and flow batteries, of three different side-chain lengths has been studied using dissipative particle dynamics (DPD) simulations. Higher and faster water uptake is usually beneficial in the operation of fuel cells and flow batteries. The simulated water uptake increased with the increasing side chain length. In addition, the water uptake was rapid initially and slowed down afterwards, which is in agreement with the experimental observations. The water cluster formation rate was also found to increase with the increasing side-chain length, whereas the water cluster shapes were unaffected. Water diffusion in the membranes, which affects proton mobility in the PEMs, increased with the side-chain length at all distances from the interface. In conclusion, side-chain length was found to have a strong influence on the interface water structure and water penetration rates, which can be harnessed for the better design of PEMs. Since the PEM can undergo cycles of dehydration and rehydration, faster water uptake increases the efficiency of these devices. We show that the longer side chains with backbone structure similar to Nafion should be more suitable for fuel cell/flow battery usage.

scholarly journals Effects of Amino Acid Side-Chain Length and Chemical Structure on Anionic Polyglutamic and Polyaspartic Acid Cellulose-Based Polyelectrolyte Brushes

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1789
Author(s):  
Dmitry Tolmachev ◽  
George Mamistvalov ◽  
Natalia Lukasheva ◽  
Sergey Larin ◽  
Mikko Karttunen
Keyword(s):  
Glutamic Acid ◽  
Chain Length ◽  
Chemical Structure ◽  
Side Chain ◽  
Side Chains ◽  
Side Chain Length ◽  
Polyelectrolyte Brushes ◽  
Grafting Density ◽  
The Difference ◽  
Cellulose Surface

We used atomistic molecular dynamics (MD) simulations to study polyelectrolyte brushes based on anionic α,L-glutamic acid and α,L-aspartic acid grafted on cellulose in the presence of divalent CaCl2 salt at different concentrations. The motivation is to search for ways to control properties such as sorption capacity and the structural response of the brush to multivalent salts. For this detailed understanding of the role of side-chain length, the chemical structure and their interplay are required. It was found that in the case of glutamic acid oligomers, the longer side chains facilitate attractive interactions with the cellulose surface, which forces the grafted chains to lie down on the surface. The additional methylene group in the side chain enables side-chain rotation, enhancing this effect. On the other hand, the shorter and more restricted side chains of aspartic acid oligomers prevent attractive interactions to a large degree and push the grafted chains away from the surface. The difference in side-chain length also leads to differences in other properties of the brush in divalent salt solutions. At a low grafting density, the longer side chains of glutamic acid allow the adsorbed cations to be spatially distributed inside the brush resulting in a charge inversion. With an increase in grafting density, the difference in the total charge of the aspartic and glutamine brushes disappears, but new structural features appear. The longer sides allow for ion bridging between the grafted chains and the cellulose surface without a significant change in main-chain conformation. This leads to the brush structure being less sensitive to changes in salt concentration.

scholarly journals Sterol side chain length and structure affect the clearance of chylomicron-like lipid emulsions in rats and mice

1998 ◽  
Vol 39 (2) ◽  
pp. 302-312 ◽  
Author(s):  
Ian J. Martins ◽  
Catherine Vilchèze ◽  
B-C. Mortimer ◽  
Robert Bittman ◽  
Trevor G. Redgrave
Keyword(s):  
Chain Length ◽  
Side Chain ◽  
Lipid Emulsions ◽  
Side Chain Length ◽  
Rats And Mice

Effect of the Side-Chain Length and NLO Properties of the N-ethyl-N,N,N-trialkylammonium Ionic Liquids – A DFT Study

2021 ◽  
pp. 116251
Author(s):  
M.A. Olea-Amezcua ◽  
J.E. Castellanos-Águila ◽  
H. HernÁndez-Cocoletzi ◽  
E. Ferreira ◽  
M. Trejo-Durán ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Chain Length ◽  
Dft Study ◽  
Side Chain ◽  
Side Chain Length ◽  
Nlo Properties

Influence of Acceptor Side-Chain Length and Conjugation-Break Spacer Content on the Mechanical and Electronic Properties of Semi-Random Polymers

2019 ◽  
Vol 1 (5) ◽  
pp. 1107-1117 ◽  
Author(s):  
Elizabeth L. Melenbrink ◽  
Kristan M. Hilby ◽  
Kartik Choudhary ◽  
Sanket Samal ◽  
Negar Kazerouni ◽  
...  
Keyword(s):  
Electronic Properties ◽  
Chain Length ◽  
Side Chain ◽  
Side Chain Length ◽  
Acceptor Side

Synthesis and solid state structures of macromolecular cylindrical brushes with varying side chain length

Polymer ◽  
2004 ◽  
Vol 45 (12) ◽  
pp. 4009-4015 ◽  
Author(s):  
Bin Zhang ◽  
Shanju Zhang ◽  
Lidia Okrasa ◽  
Tadeusz Pakula ◽  
Tim Stephan ◽  
...  
Keyword(s):  
Solid State ◽  
Chain Length ◽  
Side Chain ◽  
Side Chain Length ◽  
Solid State Structures
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