Preparation And Characterization Of New Nanocomposite Gels Based On Acrylamide

Due to the poor mechanical properties, gels prepared with chemical agent have been limited the application in many fields. So gels with excellent mechanical properties attracted the attention of many researchers. A variety of gels with high mechanical properties have been developed, such as double network gels, topological gels, tetra-PEG gels, nanocomposite gels etc., In these gels, the nanocomposite gels showed simple preparation methods, cheap raw materials and superior properties, such as high mechanical properties, excellent transmittance and good swelling etc., so nanocomposite gels have been widely concerned by researchers.In this paper, the nanocomposite gels were studied through the introduction of functional materials. Hydroxyethyl methacrylate (HEMA) was introduced into the molecular chains to prepare new Poly(AM-co-HEMA)/Clay nanocomposite gels. New PNIPA/MWNT/Clay nanocomposite gels and new PAM/MWNT/Clay nanocomposite gels were prepared by introducing multi-walled nanotube (MWNT) into the gel. The water-dispersible clay-polyaniline (PANI) composites was first prepared and reported, and introducing it into the gel, new PNIPA/PANI/Clay nanocomposite gels were prepared. The structure and properties of the obtained gels were studied and characterized. The main research are as follows:1. New poly(AM-co-HEMA)/Clay nanocomposite gels contained dual-crosslinked structure of physical and chemical were prepared by in-situ free radical polymerization, and using clay as physical cross-linking agent, N, N’-methylenebisacrylamide (MBA) as chemical cross-linking agent. The XRD results showed that the regular structure of clay has been destroyed, stripped off, and dispersed in gel randomly, and a new regular structure was founded in the gel. Mechanical experiments showed that the gel has a certain degree of compression and tensile properties, and the compression and tensile properties can be regulated by changing the ratio of AM and HEMA. And the swelling ratio and tensile strength increased with increasing AM content. For A3HC gel, when the swelling ratio was3.5, the elongation at break and tensile strength could reach370%and0.48MPa respectively.2. New PAM/MWNT/Clay nanocomposite gels contained dual-crosslinked structure of physical and chemical were prepared, by using clay as physical cross-linking agent, MBA as chemical cross-linking agent and MWNT as functional materials. The study showed that the introduction of MWNT further improved the mechanical properties and conductivity of the gel. The tensile strength and elongation at break of the gel increased with the increasing of MWNT content at the same swelling ratio. The tensile strength and elongation at break of the gel increased with the decreasing of swelling ratio at the same MWNT content. For AM2C gel, the elongation at break and tensile strength could reach620%and0.74MPa respectively. Therefore, a model that MWNT could enchance network structure in the long-distance range was brought forward. The structure analysis showed that the gel had a porous structure, and pores were mutually connected, this structure would benefit to the entry and migration of water or other molecules. Meanwhile, the introduction of MWNT also improved the conductive property of the gel, the conductivity of AM2C gel was up to1.03mS·cm-1when swelling ratio was1.8. The gel with certain mechanical properties and conductivity could be expected to be applied in the field of biosensors, chemical sensors and chemical valve etc.3. New PNIPA/MWNT/Clay nanocomposite gels were prepared through introducing MWNT into the gel. The study showed that the introduction of MWNT further improved the mechanical properties and conductivity, and also had a certain effects on the low critical solution temperature (LCST) of the gel. The DSC analysis showed that the introduction of MWNT raised LCST of the gel, and with the increasing of MWNT content, the LCST of these gels got higher, and reached37℃, which laid the foundation for the materials in some areas. Mechanical experiments showed that the gel has a certain degree of mechanical properties. When the swelling ratio was6.0, the tensile strength and elongation at break of NM2C gel could reach0.28MPa and760%respectively. Meanwhile, the introduction of MWNT also improved the conductive property of the gel, the conductivity of NM2C gel was up to 1.09mS·cm-1when swelling ratio was7.0. The structure analysis showed that the gel has a porous structure, and the pore size increased with the increasing of MWNT content.4. The water-dispersible clay-polyaniline (Clay-PANI) composites was first prepared, it was introduced into the gel, and new PNIPA/PANI/Clay nanocomposite gels were prepared. The research showed that the gel has some mechanical properties and conductivity. Mechanical experiments explained that the fracture strength of NA1C and NA2C gel could reach19.38MPa and17.45MPa respectively. The structure analysis showed that the gel has a uniform porous structure, the pore size and wall thickness increased with the increasing of PANI content. The introduction of PANI also promoted the formation of conductive network, and the conductivity of the gel increased with the increasing of PANI content, the conductivity of NA2C gel could reach0.91mS·cm-1. This gel has certain mechanical properties, uniform pore structure and conductivity, which laied some foundations for application of the materials.