The Synthetiec Procedure Research Of Ordered Mesoporous Films Based On Self-assembly Of Block Copolymer

Ordered mesoporous materials have attracted the attention of the international physical,chemical,biological and material academic circles due to the uniform pore distribution and regular pore arrangement,it becomes the hotspot of interdisciplinary research.How to improve the ordered degree of mesoporous materials and achieve macro orientation is the focus of scientists.The soft templating method based on the self-assembly of phenolic resin and block copolymer has many advantages,such as no need for reverse replication,simple preparation process,easy to control the size of mesopores,etc.,and has become one of the preferred methods for the synthesis of ordered mesoporous materials.However,due to the weak interaction between the carbon precursor and the block copolymer template,the mesoporous structure is likely to collapse during the heat treatment process,thus destroying the order of the mesoporous film.Therefore,it is of great scientific significance and application value for the application of ordered mesoporous films to study the mechanism and process of the heat treatment process of mesoporous films to effectively improve the ordered degree of mesoporous materials.In this paper,the heat treatment process of ordered mesoporous films was observed by insitu GISAXS technology.The critical temperature point of the heat treatment of Phenolic resin-Pluronic P123 system was obtained by analyzing the change of mesoporous d-spacing.The results showed that the removal process of mesoporous film template experienced a glass-high elastic transition(about 141 ℃),high elastic-melt transition(about 264 ℃),template decomposition(about 322 ℃).The decrease of mesoporous film order mainly occurs in the process of melting and decomposition.On this basis,the influence of different heating rate in the process of template removal on the order degree of mesoporous film is studied.Optimizing heat treatment process can effectively reduce the damage of mesoporous film order in the process of template removal.In this paper,in view of the problems of traditional heat treatment,such as long process time and serious collapse of mesoporous structure,a dynamic cycle rapid heat treatment process is designed.By setting a temperature window between critical temperature points and cyclic rapid heat treatment,not only the rapid treatment of template agent is realized,but also the collapse of mesoporous film is reduced to a large extent,and the ordered degree of mesoporous film is improved.In this paper,the mesoporous structure was optimized by adjusting the process parameters of dynamic rapid heat treatment,such as cycle number and heating rate.The optimized process parameters were obtained,that is,the cycle number was 30 times,heating rate was 15 ℃/s and 30 ℃/s.The experimental results show that,after 120 ℃ heat curing,the crystal surface spacing in the direction perpendicular to(1 0)plane decreased from 10.4 nm to 7.7 nm after the traditional processing;while through dynamic rapid heat treatment,the crystal surface spacing decreased from 10.4 nm to 9.1 nm,which effectively inhibits the collapse of mesoporous channels,and the mesoporous dislocation factor is reduced by 87% compared with the traditional process.On this basis,this paper studies the application of surface modification combined with dynamic rapid heat treatment.The experimental results show that the polyelectrolyte modification method of PAH / PAA system can effectively modify the substrate surface;When the heating rate was increased from 15 ℃/s to 20 ℃/s,the angular distribution range of the mesoporous scattering ring of the samples modified by polyelectrolyte changed from 197.9 ° to 173.9 °,indicating that the order degree of the sample was improved.It has important technical guidance significance for practical application.