In this research, hydrogels based on poly vinyl alcohol and poly acrylic acid blend were prepared which were cross-linked by applied thermal conditions. Afterward, effects of time and heating on water uptake were investigated. The highest water uptake value exhibited by the sample that was heated for 20 min. at 110 ºC was about 2129% after 4 days at equilibrium state. Hydrogels exhibited p...

in this research, hydrogels based on poly vinyl alcohol and poly acrylic acid blend were prepared which were cross-linked by applied thermal conditions. afterward, effects of time and heating on water uptake were investigated. the highest water uptake value exhibited by the sample that was heated for 20 min. at 110 ºc was about 2129% after 4 days at equilibrium state. hydrogels exhibited ph-sen...

Environmentally sensitive hydrogels have enormous potential in various applications. Some environmental variables, such as low pH and elevated temperatures, are found in the body. For this reason, either pH-sensitive and/or temperature-sensitive hydrogels can be used for site-specific controlled drug delivery. Hydrogels that are responsive to specific molecules, such as glucose or antigens, can...

An inexpensive one-pot route to self-healing hydrogels with pH-tunable modulus is presented. Hydrogels were formed by reacting tannic acid, trivalent metal ions and polyallylamine. Below pH 8 the hydrogels were supramolecular while above, covalent cross-linking strengthened the hydrogels. From concentrated mixtures, threads were spun, acting as water sensitive mechanical locks.

Several kinds of biodegradable hydrogels were prepared via in situ photopolymerization of Pluronic F127/poly(ε-caprolactone) macromer and acrylic acid (AA) comonomer in aqueous medium. The swelling kinetics measurements showed that the resultant hydrogels exhibited both thermoand pH-sensitive behaviors, and that this stimuli-responsiveness underwent a fast reversible process. With increasing pH...

pH-sensitive hydrogels are suitable candidates for oral delivery of therapeutic peptides and proteins, due to their ability to respond to environmental pH changes. New pH-sensitive glycopolymers have been developed by free-radical photopolymerization of methacrylic acid and 2-methacryloxyethyl glucoside, using tetra(ethylene glycol) dimethacrylate as a cross-linking agent. To determine the suit...

The present work focused on the design of drug delivery system based on an amphiphilic and pH-sensitive hydrogel. The hydrogels were prepared via graft copolymerization of acrylic acid (AA) onto chitosan backbones by a free radical polymerization technique. The structure and surface morphology of the hydrogels were characterized by FTIR and SEM, respectively. The swelling and pH-sensitive prope...

Novel pH-sensitive hydrogels were developed as suitable candidates for carriers in bioMEMS devices as well as for oral delivery of therapeutic peptides and proteins due to their ability to respond to environmental pH change. Macromonomers containing various PEG molecular weights were synthesized and used to prepare P(MAA-g-EG) hydrogels were by photopolymerization. P(MAA-g-EG) hydrogels showed ...

The morphology of interpenetrating polymeric networks (IPNs) composed of the temperature-sensitive poly(N-isopropyl acrylamide) (PNIPAAm) and the pH-sensitive poly(methacrylic acid) (PMAA) were investigated by scanning electron microscopy (SEM). The IPN hydrogels were prepared by a sequential UV polymerization method. SEM studies were conducted on IPN hydrogel samples dried by different methods...

Hydrogels are the 3 dimensional cross linked polymeric networks which absorb the water 10-20 times of its molecular weight. Hydrogels are sensitive to different environmental stimuli like pH, temperature, ion, electric signals, light, pressure, antigen specific, enzyme sensitive, and glucose levels. When the environment is get change they get swell, and swelling is the most important characteri...