Thermoreversible Transition of Tensile Modulus of Hydrogel with Ordered Aggregates

Super-porous nanocomposite PNIPAm hydrogels reinforced with titania nanoparticles, displaying a very fast temperature response as well as pH-sensitivity

“…While swollen with water (or dissolved in it), PNIPAm undergoes a volume ''phase'' transition if it is warmed above its lower critical solution temperature (LCST, around 32°C): crosslinked PNIPAm deswells, while the linear polymer precipitates from solution [1][2][3]. The volume transition of PNIPAm can be also triggered by other stimuli like: change in solvent mixture composition [4,5], change of pH [6], electric [7] or magnetic field [8].…”

Semicrystalline Macromolecular Design by Nitroxide‐Mediated Polymerization

“…This sidechain crystallization leads to a complete loss of segmental mobility. [1][2][3][4] The synthesis of well-defined polymers containing octadecyl segments constitutes a challenge in the polymer domain. The synthesis of these polymers by conventional radical polymerization yielded materials with wide molecular-weight distributions and poorly-controlled structures.…”

Preparation and characterization of pH‐ and temperature‐responsive semi–interpenetrating polymer network hydrogels based on linear sodium alginate and crosslinked poly(N‐isopropylacrylamide)

“…7 Among these intelligent hydrogels, temperature-and pH-sensitive hydrogels are most widely investigated because these two factors are important ones inside the human body. [7][8] Poly (N-isopropylacrylamide) (PNIPAAm) hydrogel is one of the most favorable members of temperature-sensitive hydrogels studied extensively by numerous researchers as an intelligent polymeric matrix, because it undergoes sharp volume phase transition at about 33°C in aqueous solution. 9 Below the volume phase transition temperature (VPTT), the hydrogel is swollen, whereas above the VPTT, the hydrogel dehydrates to collapsed state due to the breakdown of delicate hydrophilic/hydrophobic balance in the network structure.…”