Preparation Of Inorganic Nanoparticles Toughened Composite Hydrogels

Hydrogels are polymers formed by cross-linking between polymer chains,which can store a lot of water and expand,and maintain the original cross-linked state insoluble.At the same time,hydrogels are very good soft materials,in many ways have greater application potential,for example,tissue engineering,drug controlled release,bioelectrode,catalytic reaction.Traditional hydrogels are usually a three-dimensional network of polymer chains and chemical crosslinking agents（BIS）.When the deformation occurs,the rigid chemical bonds are easily broken and the ability to withstand external forces is poor,thus limiting their application in mechanical requirements.Inorganic nanoparticles show a lot of specificity,adding nanoparticles in the gel network can enhance the hydrogel mechanics behavior and give other properties of the hydrogel.The effects of inorganic nanoparticles on the various behaviors of the gel were investigated by controlling the amount of each component.Laponite/PAAm composite hydrogels were prepared by clay Laponite and acrylamide monomer（AAm）.（TiO₂ / P（AAm-HMA））hydrogels were prepared by using titanium dioxide（P25）and hydrophobic groups as crosslinking agents and acrylamide monomers.The swelling effect of Laponite / PAAm composite hydrogel was studied by swelling experiment.The toughening mechanism of hydrogel was studied by tensile experiment.1.A series of homogeneous clay / polyacrylamide（laponite / polyacrylamide）was synthesized by thermal initiation using nano-clay（laponite）and N,N-methylenebisacrylamide（BIS）as crosslinking agent and acrylamide（AAm）PAAm)composite hydrogel.The effects of different contents of clay,N,N-methylene bisacrylamide and AAm on swelling behavior and swelling kinetics of Laponite / PAAm composite hydrogel were studied by swelling experiments.2.（TiO₂ /P（AAm-HMA））was prepared by UV-induced extraction of titanium dioxide/ acrylamide with titanium dioxide（P25）,hydrophobic group（HMA）as crosslinking agent and acrylamide（AAm）as monomer.)Hydrogels.Surface modification of titanium dioxide was characterized by infrared,thermogravimetric and transmission electron microscopy.The mechanical properties of TiO₂ / P（AAm-HMA）hydrogels were studied.The effects of different contents of titanium dioxide and hydrophobic groups on the mechanical properties of nanocomposite hydrogels were studied.In this paper,nano-clay/polyacrylamide（laponite / PAAm）composite hydrogel and titanium dioxide / acrylamide hydrophobic group copolymer（TiO₂ / P（AAm-HMA））hydrogels were successfully prepared.The swelling experiments show that nano-clay particles have a great influence on the swelling of hydrogels.The surface of the titanium dioxide is modified with trimethoxysilane methacrylate so that the titanium dioxide has the dual function of the initiator and the crosslinking agent,and the system does not need to be added with other crosslinking agents.The mechanical properties of hydrogels can be significantly increased by adding titanium dioxide and hydrophobic groups.