Rheological properties of functionalised thermosensitive copolymers for injectable applications in medicine

2012 ◽  
Vol 66 (10) ◽  
Author(s):  
Ivana Chamradová ◽  
Lucy Vojtová ◽  
Lenka Michlovská ◽  
Petr Poláček ◽  
Josef Jančář
Keyword(s):  
Rheological Properties ◽  
Sol Gel ◽  
Polymer Concentration ◽  
Test Tube ◽  
Poly Lactic Acid ◽  
Gel Point ◽  
Sol Gel Transition ◽  
Poly Ethylene ◽  
Lower Temperature ◽  
Gel Transition

AbstractFunctionalised triblock copolymers based on poly((lactic acid)-co-(glycolic acid)) and poly(ethylene glycol) (PLGA-PEG-PLGA) further modified with 3-methylenetetrahydrofuran-2,5-dione (itaconic anhydride; ITA) exhibited sol-gel transition induced by increasing temperature. Rheological properties of a series of ITA/PLGA-PEG-PLGA/ITA copolymer concentrations (6–24 mass %) in deionised Milli-Q water were studied by both the test tube inverting method (TTIM) and rheometer. The gel stiffness increased with the polymer concentration shifting the gel point of the copolymer to the lower temperature. The present study demonstrates that each method describes a sol-gel transition, but the combined method gives comprehensive information about changes in colour, viscosity, elastic and loss moduli. Characterisation of such a gel is necessary for its further use, in order to determine whether the material is appropriate as an injectable biomedical hydrogel.

Controlled Hierarchical Pore Structures in Ethylene-Bridged Polysilsesquioxane Gels

2003 ◽  
Vol 788 ◽  
Author(s):  
Yuki Kobayashi ◽  
Kazuki Nakanishi ◽  
Kazuyuki Hirao
Keyword(s):  
Phase Separation ◽  
Ethylene Glycol ◽  
Triblock Copolymers ◽  
Sol Gel ◽  
Poly Ethylene Glycol ◽  
Bridged Polysilsesquioxane ◽  
Sol Gel Transition ◽  
Poly Ethylene ◽  
Hierarchical Pore ◽  
Gel Transition

ABSTRACTFormation of hierarchical macropores and mesopores in ethylene-bridged polysilsesquioxane sol-gel systems via concurrent sol-gel transition and phase separation induced by the incorporation of supramolecular templats has been investigated. A series of poly(ethylene-glycol)-poly(propyleneglycol)- poly(ethyleneglycol) triblock copolymers, EOPOEOs, have been employed as supramolecular templates, while 1,2-bis(trimethoxysilyl)ethane was used as a polysilsesquioxane source. Successful combination of templated mesopores and well-defined macropores due to phase-separation has been found in the system with EOPOEOs having 70 PO units and respective 20 EO units. Although similar macroporous morphology has been obtained for all the EOPOEOs with EO chain longer or shorter than 20 units, the optimum composition for the co-continuous macropores and that for templated mesopores deviated from each other, resulting in the failure of producing hierarchical macropores and mesopores.

Scaling Behaviour of the Viscoelastic Properties of a Biopolymer System Near the Gel Point

1989 ◽  
Vol 177 ◽  
Author(s):  
M. A. V. Axelos ◽  
M. Kolb
Keyword(s):  
Steady State ◽  
Percolation Theory ◽  
Viscoelastic Properties ◽  
Sol Gel ◽  
Oscillatory Shear ◽  
Gel Point ◽  
Rheological Measurements ◽  
Scaling Behaviour ◽  
Sol Gel Transition ◽  
Gel Transition

ABSTRACTRheological measurements have been performed on pectin-calcium systems close to the sol-gel transition. Two different experimental setups - steady state and oscillatory shear measurements - show scaling of the viscoelastic properties. The results of both types of measurements are consistent with each other and with scalar percolation theory.

Sol-Gel Transition Kinetics of Konjac Glucomannan Dilute Solution by Fluorescence Technique

2011 ◽  
Vol 399-401 ◽  
pp. 1326-1329
Author(s):  
Dong Ying Xu ◽  
Zheng Fu Liao ◽  
Hui Wang
Keyword(s):  
Chemical Engineering ◽  
Drug Carrier ◽  
Sol Gel ◽  
Konjac Glucomannan ◽  
Gel Point ◽  
Pharmaceutical Chemical ◽  
Dilute Solution ◽  
Sol Gel Transition ◽  
Kinetics Of ◽  
Gel Transition

Konjac glucomannan (KGM) has been widely used in pharmaceutical, chemical engineering, food industry, drug carrier delivery, etc. The sol-gel transition kinetics of KGM dilute solution was studied by steady fluorescence spectroscopy in this article. The results showed that the gel point of KGM solutions depend on the concentration of KGM, pH value and temperature. The sol-gel phase transition activation energy, ΔE, was calculated to be 83.1 kJ/mol based on first reaction kinetic model.

Biomolecularly stimuli-responsive tetra-poly(ethylene glycol) that undergoes sol–gel transition in response to a target biomolecule

2017 ◽  
Vol 8 (41) ◽  
pp. 6378-6385 ◽  
Author(s):  
Chisa Norioka ◽  
Kazuma Okita ◽  
Miho Mukada ◽  
Akifumi Kawamura ◽  
Takashi Miyata
Keyword(s):  
Phase Transition ◽  
Ethylene Glycol ◽  
Sol Gel ◽  
Stimuli Responsive ◽  
Poly Ethylene Glycol ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Sol Gel Transition ◽  
Poly Ethylene ◽  
Gel Transition

We designed biotin-conjugated four-armed poly(ethylene glycol) (biotinylated Tetra-PEG) as biomolecularly stimuli-responsive polymers that underwent the phase transition from a sol to a gel state in response to avidin as a target biomolecule.

Rheological properties of poly(vinyl chloride)/plasticizer systems—relation between sol–gel transition and elongational viscosity

2007 ◽  
Vol 46 (7) ◽  
pp. 957-964 ◽  
Author(s):  
Masataka Sugimoto ◽  
Hirokazu Hida ◽  
Takashi Taniguchi ◽  
Kiyohito Koyama ◽  
Yuji Aoki
Keyword(s):  
Rheological Properties ◽  
Vinyl Chloride ◽  
Sol Gel ◽  
Elongational Viscosity ◽  
Poly Vinyl Chloride ◽  
Sol Gel Transition ◽  
Gel Transition
Sign in / Sign up

Export Citation Format

Share Document