Swelling behavior of thermosensitive nanocomposite hydrogels composed of oligo(ethylene glycol) methacrylates and clay

Thermo‐Induced Double Phase Transition Behavior of Physically Cross‐Linked Hydrogels Based on Oligo(ethylene glycol) methacrylates

“…The molar ratio of MEO 2 MA to OEGMA in the NC hydrogel as fi xed to 80 mol%: 20 mol%, which results in polymers with a responsive temperature of the NC hydrogel near the human physiological temperature, as reported in our previous work. [ 41 ] Figure 1 sharply increased to 75% within 30 min. After reaching a maximum transmittance, the sample abruptly became less transparent ( T = 10%, at 40 min), and then gradually reverts to translucency over a longer time ( T = 35%, after 120 min).…”

“…[ 39,40 ] The double phase transited hydrogels were prepared via polymerization of MEO 2 MA and OEGMA in the presence of inorganic cross-linker clay, the unique thermosensitivity of physically cross-linked NC hydrogels can be easily tuned over a wide temperature window by controlling the ratio of OEGMA units and cross-linker clay. [ 40,41 ] However, to the best of our knowledge, this thermo-induced phase transition mechanism of double thermosensitive clay/P(MEO 2 MA -co-OEGMA) NC hydrogels during the heating and cooling processes has not yet been elucidated.…”

Clay and Polymer-Based Composites Applied to Drug Release: A Scientific and Technological Prospection

“…This structure favored the release of the content by electrical stimulation which changed the redox state of the polypyrrole (55). The use of copolymers in the preparation of the composites was recurrent in the studies found (11, 29,52,55,58,60,61). The copolymers associate different polymer units, achieving synergistic effects for certain properties or associating different characteristics.…”

“…Swelling equilibrium ratio of the hydrogel containing 5 wt% montmorillonite was four times higher than the organic hydrogel, and equilibrium reestablishment with increasing temperature does not occur immediately, suggesting the application of this system for slow release of drugs. Therefore, the physically crosslinked hydrogel by Laponite proved suitable for biological applications given its volume phase transition temperature at around 40°C approaching that of the human body, and also due to the ability to reversible stimuliresponsiveness (60). Moreover, other approaches involved double-responsive composites, whose release was modulated by both pH and temperature (29,58,89).…”

Multi-responsive polymers

“…In a second part, thermoresponsive polymers have been prepared to yield schizophrenic thermoresponsive micelles, where Hoogenboom and co-workers studied UCST and LCST behavior of block copolymers containing poly(methyl acrylate) (PMA) and poly(diethylene glycol ethyl ether acrylate) (PDEGEA) segments in water and ethanol [3]. Furthermore, Zhu and coworkers investigated the swelling of thermoresponsive hydrogels prepared by poly(oligoethylene glycol) methacrylates and clay [4]. Heise's [5] and Duprez's [6] teams prepare thermoresponsive polymers capable to control the binding of specific lectin, while Roth and co-workers used the change in thermoresponsiveness for the detection of heavy metals [7].…”