Preparation of latex and metal nanoparticle doped hybrid PHEMA hydrogels and investigation of their catalytic activities

Hydrogels are cross-linked polymeric structures that exhibit a swelling tendency by absorbing water into their matrices. They swell to an equilibrium volume while maintaining their shape. The amount of water they absorb is considerably high. In recent years, due to their biocompatibility, they have been used in various applications. The most common synthetic hydrogel that is both biocompatible and naturally tissue-friendly is poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogel. Because of this property, PHEMA hydrogel has found increasing use in biomedical fields and has shown promising results. Recently, natural rubber (latex) has become an important material in industrial areas, having undergone various processes and being used in a range of applications. In the study, firstly PHEMA hydrogel synthesis was carried out using HEMA monomer. Then, poly(styrene-glycidyl methacrylate) (PSGMA) latex was synthesized using styrene and glycidyl methacrylate (GMA) monomers by emulsion polymerization method. While performing PHEMA hydrogel synthesis, PSGMA latex was added in the last stage and PHEMA-PSGMA hybrid hydrogel was obtained. Swelling study of PHEMA hydrogel and PHEMA-PSGMA hybrid hydrogels against time was performed and swelling behaviors of hydrogels in acid, base and neutral water were investigated for 48 hours. Silver nanoparticles were synthesized within the hydrogels and silver-doped hydrogels were used in the catalytic reduction study of 4-nitrophenol (4-NF) to 4-aminophenol (4-AF). Structural characterizations of PHEMA hydrogel and PHEMA-PSGMA hybrid hydrogel were performed. Firstly, thermal degradation behaviors of synthesized hydrogels were investigated with TGA-DTA device, chemical structure and functional groups of hydrogels were tried to be elucidated with FTIR spectroscopy device, diameter of latex particle was determined with zeta potentiometer device and catalytic reduction studies of hydrogels containing silver nanoparticles were carried out with UV-vis spectrophotometer device. As a result of the studies carried out, differences between PHEMA hydrogel and PHEMA-PSGMA hybrid hydrogel were tried to be revealed.