Fabrication Of Multifunctional Hydrogel With Photothermal Activity And Its Applications

Hydrogels,three-dimensional cross-linked polymer networks swollen with water molecules possess adjustable physical and chemical properties,have been widely used in various fields.Under the background of cross-integration of disciplines,multifunctional hydrogels integrating the functionality and specificity have more practical application,especially in the new scientific realm such as electronic interfaces materials and biomedical implant materials.The preparation of multifunctional hydrogels with desired functionality and excellent mechanical properties has an enormous appeal.Focusing on such a target,in this paper,we reasonably introduced the conductive polymer PEDOT:PSS and the photothermal active material H_xMoO₃ into hydrogel system.Multifunctional hydrogels with photothermal activity were obtained without compressing the mechanical properties,which providing a new idea for the building of more usable multifunctional hydrogel.The last chapter is related work in the field of electrocatalytic ammonia synthesis using BNNS stripped by supercritical carbon dioxide?SC?.The main research contents of this paper are as follows:?1?The research of multifunctional f-BNNS/PEDOT:PSS/PNIPAM hydrogelHerein,we have successfully fabricated a self-healing,conductive boron nitrogen nanosheet?f-BNNS?/PEDOT:PSS/PNIPAM hydrogel with a compressive strength of700 k Pa,a stretchability of 2666%,high adhesion and photothermal conversion capability using f-BNNS stripped by supercritical,commercial PEDOT:PSS suspension and monomer NIPAM via one-step polymerization.The ample hydrogen bonds in PNIPAM,PEDOT:PSS and functionalized BN nanosheets can provide a large number of dynamic cross-linking points,which not only improved the mechanical properties,but also contributed to the self-healing and adhesion abilities.Moreover,the introduction of PEDOT:PSS not only improves the conductivity of the hydrogel,but also enable it a fast photothermal response.More importantly,for the first time,we find that the hydrogen bonding of NIPAM and PSS can contribute to the enhanced conductivity of PEDOT:PSS owing to its capability to weaken the Coulomb interaction between the PEDOT and PSS chains.This chapter provides some new ideas for the design,preparation and application of multifunctional hydrogels,and also promotes the development of PEDOT:PSS conductivity field.?2?The fabrication and application of multifunctional Hx MohydrogelIn this work,H_xMoO₃ nanosheets with visible and near-infrared absorption were prepared by the hydrothermal method,and then H_xMoO₃ and NIPAM were copolymerized to prepare multifunctional Hx Mohydrogels with photothermal activity and high mechanical properties.The hydrogel has a three-dimensional porous structure.Due to the presence of the hydrophilic polymer chain PNIPAM,the hydrogel can also promote the evaporation of water.Finally,we integrated the hydrogel specificity and functionality to prepare a hydrogel-based solar steamer,and obtained a high water evaporation rate of 1.65 kg m^-2 h^-1 with the energy efficiency of 89%under 1 k W m^-2 irradiation.?3?The fabrication of BNNS stripped by SCand its application on NRRIn this work,for the first time,we prepared BNNS as a metal-free catalyst for the electrocatalytic synthesis of ammonia with a yield(8.39?g h^-1 mg^-1_cat.)and a high Faraday efficiency?27.7%?by using green chemistry.Our experiments demonstrate that a large amounts of?100?crystal planes of uniformly sized BNNS are exposed.The unsaturated B atoms at the edges of the jagged BNNS provide ample active sites for the adsorption and activation of N₂.