Preparation Of LDH-carbon Hybrid Materials And Their Applications In PVA

In recent years,inorganic layered double hydroxides(LDHs),one-dimensional carbon nanotubes(CNTs),two-dimensional layered graphene and reduced graphene oxide(rGO)are widely popular with the scientific research workers.Single nanometer materials are easy to aggregation,which largely limits their application.The multi-dimensional novel materials based on carbon materials and layered nanofillers can give full play to the advantages of themselves,and restrain the nanoparticles from aggregation.Three high performance nanoparticles were adopted in this paper,namely LDHs,CNTs and graphene.The preparation and structure of LDH-CNTs and LDH-rGO hybrid nanoparticles,and their applications in polyvinyl alcohol(PVA)were explored.The main contents were summarized as follows:Firstly,the 3D LDH-aCNTs hybrid nanoparticles were successfully prepared via the constant pH coprecipitation method.Mg2+ and Al3+ ion adsorbed on the surfaces of aCNTs and in situ nucleation and growth on aCNTs.The influence of the method of aCNTs addition,the aging conditions and aCNTs contents on the microstructure were investigated.The results showed that the aggregation of LDHs and aCNTs were improved when the aging temperature was 70 °C,the aging time was 8h,the mass ratio of LDHs and CNTs was about 5 and aCNTs adding into the reaction vessels in one batch.In addition,the mechanical properties of PVA were effectively enhanced by introduction of LDH-aCNTs.In order to further improve the performance of multi-dimensional hybrid nanoparticles and broaden its application scope,the multi-dimensional LDH-rGO hybrid nanoparticles were obtained by combining the excellent performance rGO and LDHs.The prepared LDH-rGO hybrids were directly used as reinforcing nanofillers to prepare PVA/LDH-rGO composite films by solution casting method.The PVA/LDH-rGO films exhibited excellent mechanical properties and good barrier properties.The elongation at break increased by 59% with addition of 0.5 wt% LDH-rGO into PVA and the OTR of PVA/LDH-rGO films with the incorporation of 1 wt% LDH-rGO hybrids decreased by 86%,respectively.The enhanced mechanical and barrier properties of PVA films were attributed to uniformly dispersion of LDH-rGO hybrids,and strong interfacial interaction between the filler and polymer.Based on the above researches,the LDH-CNT-rGO were prepared and the hybrid mechanism was simply studied among LDHs,CNTs and rGO.The PVA composite films were obtained by in situ coprecipitation method and simple solution blending method,and compared the performance of PVA composite films in order to maximize simplified the process of the preparation of polymer matrix composite film.