Photocontrollable volume phase transition of an azobenzene functionalized microgel and its supramolecular complex

RSC Advances ◽  
2015 ◽  
Vol 5 (102) ◽  
pp. 84263-84268 ◽  
Author(s):  
Liqiang Zhu ◽  
Chuanzhuang Zhao ◽  
Jiawei Zhang ◽  
Dirong Gong
Keyword(s):  
Phase Transition ◽  
Acrylic Acid ◽  
Supramolecular Complex ◽  
Volume Phase Transition ◽  
Volume Phase

A novel photo-responsive microgel (Azo-MG) was successfully prepared by grafting azobenzene moieties onto a poly(N-isopropylacrylamide-co-acrylic acid) microgel.

Influence of imidazolium based green solvents on volume phase transition temperature of crosslinked poly(N-isopropylacrylamide-co-acrylic acid) hydrogel

Soft Matter ◽  
2015 ◽  
Vol 11 (4) ◽  
pp. 785-792 ◽  
Author(s):  
Chi-Jung Chang ◽  
P. Madhusudhana Reddy ◽  
Shih-Rong Hsieh ◽  
Hsin-Chun Huang
Keyword(s):  
Phase Transition ◽  
Ionic Liquids ◽  
Transition Temperature ◽  
Acrylic Acid ◽  
Phase Transition Temperature ◽  
Polymeric Material ◽  
Volume Phase Transition ◽  
Green Solvents ◽  
Stimuli Responsive ◽  
Volume Phase

Ionic liquids, known as green solvents, can be used effectively to obtain the desired phase transition temperature for a given stimuli responsive polymeric material.

Kinetics of Volume Phase Transition in Poly(N-isopropylacrylamide-co-acrylic acid) Gels

1998 ◽  
Vol 31 (16) ◽  
pp. 5336-5342 ◽  
Author(s):  
Hiroshi Hirose ◽  
Mitsuhiro Shibayama
Keyword(s):  
Phase Transition ◽  
Acrylic Acid ◽  
Volume Phase Transition ◽  
Volume Phase ◽  
Kinetics Of

Triply-responsive OEG-based microgels and hydrogels: Regulation of swelling ratio, volume phase transition temperatures and mechanical properties

2021 ◽  
Author(s):  
Dongdong Lu ◽  
Mingning Zhu ◽  
Jing Jin ◽  
Brian R. Saunders
Keyword(s):  
Phase Transition ◽  
Biomedical Engineering ◽  
Volume Phase Transition ◽  
Swelling Ratio ◽  
Transition Temperatures ◽  
Ph Responsive ◽  
Network Systems ◽  
Volume Phase ◽  
Phase Transition Temperatures ◽  
Volume Swelling

Thermally- and pH-responsive microgels (MGs) and hydrogels are fascinating network systems that have been applied in biomedical engineering and sensing. The volume-swelling ratio (Q) and the volume-phase transition temperatures (VPTTs)...

scholarly journals Accounting for Cooperativity in the Thermotropic Volume Phase Transition of Smart Microgels

Gels ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 42
Author(s):  
Simon Friesen ◽  
Yvonne Hannappel ◽  
Sergej Kakorin ◽  
Thomas Hellweg
Keyword(s):  
Phase Transition ◽  
Interaction Parameter ◽  
Quantitative Description ◽  
Water Molecules ◽  
Volume Phase Transition ◽  
Network Chain ◽  
Solvent Interaction ◽  
Volume Phase ◽  
The Cross ◽  
Interaction Parameter Χ

A full quantitative description of the swelling of smart microgels is still problematic in many cases. The original approach of Flory and Huggins for the monomer–solvent interaction parameter χ cannot be applied to some microgels. The reason for this obviously is that the cross-linking enhances the cooperativity of the volume phase transitions, since all meshes of the network are mechanically coupled. This was ignored in previous approaches, arguing with distinct transition temperatures for different meshes to describe the continuous character of the transition of microgels. Here, we adjust the swelling curves of a series of smart microgels using the Flory–Rehner description, where the polymer–solvent interaction parameter χ is modeled by a Hill-like equation for a cooperative thermotropic transition. This leads to a very good description of all measured microgel swelling curves and yields the physically meaningful Hill parameter ν. A linear decrease of ν is found with increasing concentration of the cross-linker N,N′-methylenebisacrylamide in the microgel particles p(NIPAM), p(NNPAM), and p(NIPMAM). The linearity suggests that the Hill parameter ν corresponds to the number of water molecules per network chain that cooperatively leave the chain at the volume phase transition. Driven by entropy, ν water molecules of the solvate become cooperatively “free” and leave the polymer network.

Influence of volume phase transition phenomena on the behavior of hydrogel-based valves

2004 ◽  
Vol 99 (2-3) ◽  
pp. 451-458 ◽  
Author(s):  
Andreas Richter ◽  
Steffen Howitz ◽  
Dirk Kuckling ◽  
Karl-Friedrich Arndt
Keyword(s):  
Phase Transition ◽  
Volume Phase Transition ◽  
Volume Phase
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