Design And Research Of Multilayer Bionic Composite Film

Nacre-like hierarchical structural materials are a family of high performance materials which were developed from bionics.Owing to their high strengthness and toughness,nacre-like hierarchical structural materials have been an ideal candidate of traditional structural materials and have found potential application in a large number of fields.Nacre-like hierarchical structural materials generally possess the feature of brick-structure and constructed by the layer-by-layer of hard and soft materials.The hard materials act as the backbone and afford high strength,while the soft materials play as the adhesive of hard materials and afford high toughness.Currently,the hard components are mainly consisted by inorganic aragonite materials and the soft components were generally flexible polymer,graphene,etc.Organosilicon materials have widly used in the applications,such as electronic packagaing,coating,damping,etc.However,owing to the poor interchain interaction,the impact performance of organsilicon materials is not satisfactory.It is a potential way to improve the mechanical performance via constructing all-organosilicon nacre-like materials.In terms of this point,in this work,the performance of MK resin and silicon elastomer were investigated to evaluate their potential use as hard and soft components for all-organosilicon nacre-like materials.Firstly,acrylate groups were introduced to synthesize photoactive MK resins.Subsequently,di(trimethoxy)silane was added to form organosilicon resin.The results showed that the hardness and toughness of resins were simultaneously increased because di(trimethoxy)silane can increase cross-linking density and the relatively long carbon chain endows the resin with chain mobility.At the same time,the hardness of MK resin increased from 90 MPa to 130 MPa,and the elastic modulus increased from 2 GPa to 2.5 GPa.When further increasing the content of di(trimethoxy)silane to,the hardness and toughness were decreased.This result indicated that the introduction of excessive di(trimethoxy)silane failed to increase cross-linking density.In contrast,the presence of more flexible chains made the hardness decrease.The use of di(trimethoxy)silane with relatively long carbon chains produced the resin with lower hardness but higher toughness.This result further verified the tenability of the flexibility of carbon chains on the mechanical performance of the resins.Above investigation will provide insight on the design of siloxane bio-inspired rigid materials.In the second section,the adhesion technology and performance of soft organosilicon polymer was investigated.The soft organosilicon polymer was successfully transferred to the surface of substrated by imprinting.The adhesion between the substrates was then realized.After the surface treatment by plasma etching,the peeling strength can reach to around32.1N/mm.Further investigation indicated that the curing method,the ratio of prepolymer to cross-linker,the plasma power could affect the transfer of PDMS.The transfer of PDMS was enhanced by increasing the the ratio of prepolymer to cross-linker and the plasma power.