Novel amphiphilic network polymers consisting of nonpolar, short primary polymer chains and polar, long crosslink units: Influence of characteristic dangling chains on swelling behavior of resulting amphiphilic gels

2004 ◽  
Vol 42 (9) ◽  
pp. 2192-2201 ◽  
Author(s):  
Masato Doura ◽  
Hiroyuki Aota ◽  
Akira Matsumoto
Keyword(s):  
Swelling Behavior ◽  
Polymer Chains ◽  
Network Polymers

scholarly journals Crosslinker-Based Regulation of Swelling Behavior of Poly(N-isopropylacrylamide) Gels in a Post-Polymerization Crosslinking System

Gels ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 2
Author(s):  
Shohei Ida ◽  
Akimitsu Katsurada ◽  
Mitsuhiro Tsujio ◽  
Motoharu Nakamura ◽  
Yoshitsugu Hirokawa
Keyword(s):  
Solvent Effect ◽  
Structural Diversity ◽  
Soft Materials ◽  
Polymer Gels ◽  
Crosslinking Density ◽  
Swelling Behavior ◽  
Polymer Chains ◽  
Gel Properties ◽  
Alkyl Chains ◽  
Fundamental Understanding

A fundamental understanding of the effect of a crosslinker on gel properties is important for the design of novel soft materials because a crosslinking is a key component of polymer gels. We focused on post-polymerization crosslinking (PPC) system utilizing activated ester chemistry, which is a powerful tool due to structural diversity of diamine crosslinkers and less susceptibility to solvent effect compared to conventional divinyl crosslinking system, to systematically evaluate the crosslinker effect on the gel properties. A variety of alkyldiamine crosslinkers was employed for the synthesis of poly(N-isopropylacrylamide) (PNIPAAm) gels and it was clarified that the length of alkyl chains of diamine crosslinkers strongly affected the gelation reaction and the swelling behavior. The longer crosslinker induced faster gelation and decreased the swelling degree and the response temperature in water, while the crosslinking density did not significantly change. In addition, we were able to modify the polymer chains in parallel with crosslinking by using a monoamine modifier along with a diamine crosslinker. This simultaneous chain modification during crosslinking (SMC) was demonstrated to be useful for the regulation of the crosslinking density and the swelling behavior of PNIPAAm gels.

scholarly journals Effects of bond exchange reactions and relaxation of polymer chains on the thermomechanical behaviors of covalent adaptable network polymers

Polymer ◽  
2018 ◽  
Vol 153 ◽  
pp. 43-51 ◽  
Author(s):  
Chaoqian Luo ◽  
Xiaojuan Shi ◽  
Zepeng Lei ◽  
Chengpu Zhu ◽  
Wei Zhang ◽  
...  
Keyword(s):  
Polymer Chains ◽  
Exchange Reactions ◽  
Network Polymers

Novel flexible network polymers consisting of oligomeric primary polymer chains originated in the mechanistic discussion of multiallyl crosslinking polymerization

2006 ◽  
Vol 58 (1) ◽  
pp. 173-184 ◽  
Author(s):  
Akira Matsumoto ◽  
Masato Doura ◽  
Tadahiro Kiguchi ◽  
Hideo Ito ◽  
Hiroyuki Aota
Keyword(s):  
Polymer Chains ◽  
Network Polymers

Shape of Confined Polymer Chains

1997 ◽  
Vol 7 (3) ◽  
pp. 433-447 ◽  
Author(s):  
C. E. Cordeiro ◽  
M. Molisana ◽  
D. Thirumalai
Keyword(s):  
Polymer Chains ◽  
Confined Polymer ◽  
Confined Polymer Chains

Dynamics of polymer chains trapped in a slit

1977 ◽  
Vol 38 (10) ◽  
pp. 1285-1291 ◽  
Author(s):  
F. Brochard
Keyword(s):  
Polymer Chains

SuFExable Polymers with Helical Structures Derived from Thionyl Tetrafluoride (SOF4)

2019 ◽  
Author(s):  
Suhua Li ◽  
Gencheng Li ◽  
Bing Gao ◽  
Sidharam P. Pujari ◽  
Xiaoyan Chen ◽  
...  
Keyword(s):  
Functional Polymers ◽  
Polymer Chains ◽  
New Materials ◽  
Helical Structures ◽  
Polymer Backbone ◽  
Silyl Ethers ◽  
Helical Polymer ◽  
Key Characteristics ◽  
Post Modification ◽  
Individual Polymer

The first SuFEx click chemistry synthesis of SOF<sub>4</sub>-derived copolymers based upon the polymerization of bis(iminosulfur oxydifluorides) and bis(aryl silyl ethers) is described. This novel class of SuFEx polymer presents two key characteristics: First, the newly created [-N=S(=O)F-O-] polymer backbone linkages are themselves SuFExable and primed to undergo further high-yielding and precise SuFEx-based post-modification with phenols or amines to yield branched functional polymers. Second, studies of individual polymer chains of several of these new materials indicate the presence of helical polymer structures, which itself suggests a preferential approach of new monomers onto the growing polymer chain upon the formation of the stereogenic linking moiety.

Microstructure determines water and salt permeation in commercial ion exchange membranes

2018 ◽  
Author(s):  
Ryan Kingsbury ◽  
Shan Zhu ◽  
Sophie Flotron ◽  
Orlando Coronell
Keyword(s):  
Energy Efficiency ◽  
Ion Exchange ◽  
Electrolyte Solutions ◽  
Polymer Chains ◽  
Salt Transport ◽  
Mixing Energy ◽  
Electrochemical Processes ◽  
Highly Correlated ◽  
Salt Diffusion ◽  
Exchange Membrane

Ion exchange membrane (IEM) performance in electrochemical processes such as fuel cells, redox flow batteries, or reverse electrodialysis (RED) is typically quantified through membrane selectivity and conductivity, which together determine the energy efficiency. However, water and co-ion transport (i.e., osmosis and salt diffusion / fuel crossover) also impact energy efficiency by allowing uncontrolled mixing of the electrolyte solutions to occur. For example, in RED with hypersaline water sources, uncontrolled mixing consumes 20-50% of the available mixing energy. Thus, in addition to high selectivity and high conductivity, it is desirable for IEMs to have low permeability to water and salt in order to minimize energy losses. Unfortunately, there is very little quantitative water and salt permeability information available for commercial IEMs, making it difficult to select the best membrane for a particular application. Accordingly, we measured the water and salt transport properties of 20 commercial IEMs and analyzed the relationships between permeability, diffusion and partitioning according to the solution-diffusion model. We found that water and salt permeance vary over several orders of magnitude among commercial IEMs, making some membranes better-suited than others to electrochemical processes that involve high salt concentrations and/or concentration gradients. Water and salt diffusion coefficients were found to be the principal factors contributing to the differences in permeance among commercial IEMs. We also observed that water and salt permeability were highly correlated to one another for all IEMs studied, regardless of polymer type or reinforcement. This finding suggests that transport of mobile salt in IEMs is governed by the microstructure of the membrane, and provides clear evidence that mobile salt does not interact strongly with polymer chains in highly-swollen IEMs. <br>

Dynamics of Ion Locking in Doubly Polymerized Ionic Liquids

2020 ◽  
Author(s):  
Swati Arora ◽  
Julisa Rozon ◽  
Jennifer Laaser
Keyword(s):  
Dielectric Constant ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Ion Pairs ◽  
Polymer Chains ◽  
Ion Motion ◽  
Charged Species ◽  
Broadband Dielectric Spectroscopy ◽  
Covalently Linked ◽  
Insight Into

<div>In this work, we investigate the dynamics of ion motion in “doubly-polymerized” ionic liquids (DPILs) in which both charged species of an ionic liquid are covalently linked to the same polymer chains. Broadband dielectric spectroscopy is used to characterize these materials over a broad frequency and temperature range, and their behavior is compared to that of conventional “singly-polymerized” ionic liquids (SPILs) in which only one of the charged species is attached to the polymer chains. Polymerization of the DPIL decreases the bulk ionic conductivity by four orders of magnitude relative to both SPILs. The timescales for local ionic rearrangement are similarly found to be approximately four orders of magnitude slower in the DPILs than in the SPILs, and the DPILs also have a lower static dielectric constant. These results suggest that copolymerization of the ionic monomers affects ion motion on both the bulk and the local scales, with ion pairs serving to form strong physical crosslinks between the polymer chains. This study provides quantitative insight into the energetics and timescales of ion motion that drive the phenomenon of “ion locking” currently under investigation for new classes of organic electronics.</div>

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