Phase transition in polymer gels induced by visible light

摘要: PHASE transitions and critical phenomena in polymer gels have attracted much attention because of their scientific interest technological significance1–3. Phase accompanied by a reversible, discontinuous volume change as large several hundred times, response to infinitesimal changes environmental conditions, been observed universally made synthetic natural polymers1–9. induced varying temperature, solvent composition, pH, ionic composition small electric field10. Recently, sensitive ultraviolet light were also reported11. The initiates an ionization reaction the gel, creating internal osmotic pressure which induces swelling. In absence this light, equilibrium tends towards neutral system gel collapses. This transition process is slow, it depends on photochemical subsequent recombination ions, technologically desirable that be faster mechanisms. Also, visible less harmful more abundant than sunlight. Hence we now report phase where mechanism due only direct heating network polymers extremely fast process. Such systems might used photoresponsive artificial muscles, switches memory devices.