由光敏性全氢聚硅氮烷制备透明高硬Si—O微/纳米结构压印模板

面向可用作压印模板的透明高硬微/纳米结构的低成本制备,无机高分子全氢聚硅氮烷用甲基丙烯酸(2-异氰酸基乙酯)进行光敏改性,经FTIR,1H-NMR,13C-NMR等手段表征,推断获得的是甲基丙烯酸酯化的全氢聚硅氮烷(MPHPS),并以此为原料,用一种含氟聚合物(FP)模板,施加0.1～0.4 MPa的压力,紫外压印制备MPHPS的微结构,发现增加压力,压印复制效果提高,0.23 MPa可以完全复制FP模板的微结构.此外,在0.4 MPa的压力下也制备了分辨率为90 nm,70 nm的纳米级结构.随后在碱性条件下室温水解,MPHPS聚合物结构转化为Si—O无机结构,最终获得透明高硬结构,硬度4.5×103MPa,弹性模量115×103MPa.

HIGH RESOLUTION SILICA IMPRINTING MOLD FABRICATED FROM A PHOTOCURABLE PERHYDROPOLYSILAZANE

Towards the low-cost fabrication of a hard imprinting mold with micro-and nanostructures,a novel photocurable inorganic polymer was modified from perhydropolysilazane(PHPS) by grafting with 2-isocyanatoethyl methacrylate(ICMA) in this paper.The as-modified product was characterized by the methods of FTIR,1H-NMR,13C-NMR and 2D-1H-1H-NMR(COSY).The new peaks at δ=3.2~3.8 on1H-NMR spectra of the product were assigned to be the NH—CH2 group,and δ=152~158 on 13C-NMR spectra was assigned to be the CO—NH group.In the FTIR spectra,the absorbing peaks at 2153 and 1363 cm-1(N-C-O),1117 cm-1(—C—N-C) of PHPS were obviously consumed after chemical modification,and the new peaks at 1690,1530 and 1314 cm-1(CO—NH)were appeared.Combined with the COSY analysis,it was concluded that the UV sensitive methacrylyate group was successfully grafted to PHPS,and methacrylated perhydropolysilazane(MPHPS) was used to name the as-modified product here.MPHPS was then used to fabricate the micro-and nanostructures via UV imprinting lithography using a fluoropolymer(FP) mold with microstructures,adding a pressure ranged in 0.1~0.4 MPa.The efficiency of the pattern transfer from FP mold was increased by the pressure increasing,and the thoroughly pattern copy was realized at 0.23 MPa.Besides,nanostructures with 90 nm,70 nm feature sizes were obtained at the pressure of 0.4 MPa.Then the as-prepared micro-and nanostructures were converted into Si—O inorganic phase by a followed hydrolysis treatment.The converted product was concluded to be a composition of SiO1.5 from XPS depth profile.The final obtained mold was optical transparent,and with a hardness of 4.5×103 MPa and a elastic modulus of 115×103 MPa.