Assembly Pattern of Supramolecular Hydrogel Induced by Lower Critical Solution Temperature Behavior of Low-Molecular-Weight Gelator

2019 ◽  
Vol 142 (1) ◽  
pp. 448-455 ◽  
Author(s):  
Shuanggen Wu ◽  
Qiao Zhang ◽  
Yan Deng ◽  
Xing Li ◽  
Zheng Luo ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Lower Critical Solution Temperature ◽  
Temperature Behavior ◽  
Solution Temperature ◽  
Low Molecular Weight ◽  
Supramolecular Hydrogel ◽  
Critical Solution Temperature ◽  
Low Molecular Weight Gelator

Effect of the molecular weight on the lower critical solution temperature of poly(N,N-diethylacrylamide) in aqueous solutions

2001 ◽  
Vol 79 (12) ◽  
pp. 1870-1874 ◽  
Author(s):  
D G Lessard ◽  
M Ousalem ◽  
X X Zhu
Keyword(s):  
Molecular Weight ◽  
Lower Critical Solution Temperature ◽  
Molar Mass ◽  
Average Molecular Weight ◽  
Solution Temperature ◽  
Low Molecular Weight ◽  
Fractional Precipitation ◽  
Critical Solution Temperature ◽  
Molecular Weight Dependence ◽  
Critical Molecular Weight

The molecular weight dependence of the lower critical solution temperature of poly(N,N-diethylacrylamide) was studied with 11 samples of the polymer with a number-average molecular weight (Mn) ranging from 9.6 × 103 to 1.3 × 106 g mol–1 and relatively narrow polydispersity indices from 1.19 and 2.60. These samples were obtained by fractional precipitation of the polymer. LCST values of polymers were measured by turbidimetry and microcalorimetry. An inverse dependence of LCST on the molar mass was found and the LCST of the samples remained more or less a constant above a critical molecular weight of ca. 2 × 105 g mol–1. The enthalpy and the entropy changes as well as the LCST of the polymer depend strongly on the molar mass of the polymer, especially in low molecular weight range.Key words: poly(N,N-diethylacrylamide), LCST, thermosensitive, phase diagram, effect of molecular weight.

A degradable low molecular weight monomer system with lower critical solution temperature behaviour in water

2019 ◽  
Vol 55 (6) ◽  
pp. 782-785 ◽  
Author(s):  
Bo Zheng ◽  
Zheng Luo ◽  
Yan Deng ◽  
Qiao Zhang ◽  
Lingyan Gao ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Crown Ether ◽  
Small Molecule ◽  
Lower Critical Solution Temperature ◽  
Solution Temperature ◽  
Low Molecular Weight ◽  
Temperature Behaviour ◽  
Critical Solution Temperature

A small molecule system showing LCST was prepared and the degradation of the crown ether motif effectively altered the thermo-responsiveness.

scholarly journals Insights on the Lower Critical Solution Temperature Behavior of pNIPAM in an Applied Electric Field

2020 ◽  
Vol 97 (7) ◽  
pp. 709-715
Author(s):  
Joelle LaFreniere ◽  
Emma Roberge ◽  
Tianyu Ren ◽  
William Rudolf Seitz ◽  
Eva Rose M Balog ◽  
...  
Keyword(s):  
Electric Field ◽  
Lower Critical Solution Temperature ◽  
Applied Electric Field ◽  
Temperature Behavior ◽  
Solution Temperature ◽  
Critical Solution Temperature

scholarly journals Effect of Hydrophobic Interactions on Lower Critical Solution Temperature for Poly(N-isopropylacrylamide-co-dopamine Methacrylamide) Copolymers

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 991 ◽  
Author(s):  
Alberto García-Peñas ◽  
Chandra Sekhar Biswas ◽  
Weijun Liang ◽  
Yu Wang ◽  
Pianpian Yang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Lower Critical Solution Temperature ◽  
Hydrophobic Interactions ◽  
Structural Information ◽  
Drug Carriers ◽  
Solution Temperature ◽  
Polymerization Degree ◽  
Tissue Engineering Scaffolds ◽  
Critical Solution Temperature ◽  
Precise Control

For the preparation of thermoresponsive copolymers, for e.g., tissue engineering scaffolds or drug carriers, a precise control of the synthesis parameters to set the lower critical solution temperature (LCST) is required. However, the correlations between molecular parameters and LCST are partially unknown and, furthermore, LCST is defined as an exact temperature, which oversimplifies the real situation. Here, random N-isopropylacrylamide (NIPAM)/dopamine methacrylamide (DMA) copolymers were prepared under a systematical variation of molecular weight and comonomer amount and their LCST in water studied by calorimetry, turbidimetry, and rheology. Structural information was deduced from observed transitions clarifying the contributions of molecular weight, comonomer content, end-group effect or polymerization degree on LCST, which were then statistically modeled. This proved that the LCST can be predicted through molecular structure and conditions of the solutions. While the hydrophobic DMA lowers the LCST especially the onset, polymerization degree has an important but smaller influence over all the whole LCST range.

Thermoresponsive polymers with lower critical solution temperature: from fundamental aspects and measuring techniques to recommended turbidimetry conditions

2017 ◽  
Vol 4 (2) ◽  
pp. 109-116 ◽  
Author(s):  
Qilu Zhang ◽  
Christine Weber ◽  
Ulrich S. Schubert ◽  
Richard Hoogenboom
Keyword(s):  
Lower Critical Solution Temperature ◽  
Temperature Behavior ◽  
Solution Temperature ◽  
Thermoresponsive Polymers ◽  
Critical Solution Temperature ◽  
Measuring Techniques

This focus article addresses fundamental and practical aspects of investigating polymers with lower critical solution temperature behavior.

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