超重力反应结晶-萃取相转移法可控制备纳米金属氢氧化物透明分散体机制及应用基础

Optically transparent organic-inorganic nanocomposites have great potential applications. The related key science problems are how to control size and uniformity of nanoparticles, as well as the dispersity in transparent polymer matrix. The controlled preparation of highly transparent liquid dispersions of nanoparticles could resolve these problems. This project aims to the practical application demands for transparent flame retardant polymer materials. A kind of new material of transparent nanosized metal hydroxide dispersions for flame retardant application is thus presented. Based on functionally guided active design of surface and the control principle of molecular reaction engineering, a novel way to prepare highly transparent liquid dispersions of nanosized magnesium/aluminum based hydroxide for flame retardant by high gravity reaction crystallization-phase transfer technology is proposed. These nanoparticles will be well dispersed in transparent polymer matrix by high efficient process, thereby low-cost preparation of high-performance flexible transparent flame retardant polymer nanocomposite film materials. This project mainly investigates the interaction of surfactant, particle surface and dispersion media; studies the preparation mechanism of highly transparent liquid dispersions of metal hydroxide nanoparticles for flame retardant by intensifying molecular mixing and mass transfer in high gravity reactor; explores the rules of mixing, mass transfer, particle nucleation, growth and dispersion in the coupling process of reaction, crystallization and phase transfer; prepares high-performance low-cost flexible transparent nanocomposite materials for flame retardant and build the structure-function relationship of preparation process, shape and structure, and application property. The implementation of this project will provide the technology and theoretical basis for the controllable preparation and application of transparent flame retardant nanodispersions.

透明有机无机纳米复合材料有巨大应用前景，涉及的关键科学问题是如何调控纳米颗粒尺寸、均一性，及其在透明聚合物中的分散性，纳米颗粒透明分散体制备可解决此问题。本项目围绕柔性透明聚合物阻燃材料实际应用需求，提出阻燃用纳米金属氢氧化物透明液相分散体新材料；进而通过功能导向表面主动设计，基于分子反应工程调控原理，提出超重力反应结晶-萃取相转移法可控制备纳米镁铝基氢氧化物透明分散体新技术；进一步将此新材料高效复合分散于柔性透明聚合物基体中，实现高性能柔性透明阻燃纳米复合材料的创制。重点研究表面修饰剂与颗粒表面、分散介质间的相互作用；探寻纳米镁铝基氢氧化物透明分散体可控制备的理论机制，研究超重力环境下反应结晶-萃取相转移耦合过程中分子混合、传质、颗粒成核、生长与分散规律；构建制备工艺-形态结构-应用性能间的本构关系。本项目的实施将为阻燃用纳米颗粒透明分散体的可控制备和应用提供技术路线和理论基础。

纳米颗粒的分散是其应用的核心难题。当纳米颗粒尺寸足够小且分散良好时，其分散在溶剂中形成的液相纳米分散体，通常具有良好的透明性或明显的丁达尔效应。纳米分散体材料较传统的纳米粉体材料更易于在聚合物基体中分散和应用，具有更优异的性能，是制备透明有机无机纳米复合材料的重要中间体。.本项目围绕透明聚合物阻燃材料实际应用需求，提出阻燃用纳米金属氢氧化物透明液相分散体新材料；进而通过功能导向表面主动设计，基于分子反应工程调控原理，提出超重力反应结晶-萃取相转移法可控制备纳米镁铝基氢氧化物透明分散体新技术；进一步将此新材料高效复合分散于透明聚合物基体中，实现高性能透明阻燃纳米复合材料的创制。. 本项目的研究内容和任务按计划已全面完成。本项目采用超重力反应结晶-萃取相转移法成功制备出了Mg(OH)2、Al(OH)3、Mg-Al-CO3 LDHs等多种纳米金属氢氧化物透明分散体，分散介质可为水、醇或甲苯等，形成了可控制备平台；研究并揭示了相关分散体材料的可控制备机制。相比于传统釜式法，超重力法所得产品平均粒径更小，透明性更好，固含量更高；更重要的是，反应过程从间歇变成了连续。此外，本项目还利用所得透明纳米分散体，通过溶液共混等复合方法，创制出了PVA/Mg(OH)2、PET/Mg(OH)2、PP/Mg(OH)2多种高性能透明阻燃纳米复合材料，所得材料具有良好的阻燃、抗熔滴及力学性能。本项目已在AIChE J.、Ind. Eng. Chem. Res.、Chem. Eng. J.、Nanotechnology等国外权威期刊上发表SCI论文10篇；申请相关中国发明专利3件（已授权1件），另授权美国发明专利1件，中国发明专利3件；培养博士和硕士生4名。