A kind of flexible photonic crystal element nano-microsphere and its preparation method

Abstract

The invention relates to a preparation method of nano microspheres, in particular to a flexible photonic crystal element nano microsphere and a preparation method thereof. The nanospheres are made of the following raw materials by weight percentage: emulsifier 0.02~0.04 wt%, inner layer hard monomer 4~7 wt%, inner layer crosslinking agent, inner layer crosslinking agent is inner layer hard monomer content of 5~15 wt%, outer layer monomer 9‑15 wt%, outer layer crosslinking agent, outer layer crosslinking agent is 0.1~1 wt% of outer layer monomer content, initiator, initiator is inner layer 1~3 wt% of the total amount of hard monomer and outer layer monomer; the balance is water. The present invention can effectively prepare soft nano microspheres through two-step emulsion polymerization, and the softness and hardness of the outer layer can be controlled very simply by means of copolymerization of soft and hard monomers. The inner layer cross-linking agent can make double bonds exist on the surface of the inner core, and at the same time, the outer layer monomer can be anchored on the inner core surface through the action of the outer layer cross-linking agent, making the structure more stable.

Description

technical field [0001] The invention relates to a preparation method of nano microspheres, in particular to a flexible photonic crystal element nano microsphere and a preparation method thereof. Background technique [0002] Photonic crystal is a dielectric material with highly ordered structure. Due to its own photonic band gap, it can prevent visible light equivalent to the forbidden band from passing through photonic crystal and being selectively reflected, forming constructive interference on its surface. Chromogenic materials with photonic crystal structure have attracted extensive attention in many fields such as smart response, smart display, sensing, printing and printing, and textile coloring. However, the commonly used photonic crystal building blocks are usually silicon oxide (SiO 2 ), polystyrene (PS) and polymethylmethacrylate (PMMA) and other hard nanospheres, such microspheres cannot construct flexible photonic crystal structures, which largely limits their p...

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Problems solved by technology

However, during the reaction process, the monomers of the core layer and the shell layer will undergo a certain copolymerization reaction, and it is difficult to controllably adjust the softness and hardness of the obtained nanospheres.

Pre-emulsification-semi-batch emulsion polymerization is to precisely control the composition of the inner core and shell of the nano-microspheres by step-by-step feeding, so as to obtain the required soft nano-microspheres, but the monomers to be reacted are pre-emulsified in the reaction process It needs to be added in four times, and the prepared nano-microspheres are composed of three parts: core-transition layer-shell. The soft shell needs to rely on the transition layer for bridging and anchoring on the surface of the hard core. Limit the preparation efficiency of nanospheres to a certain extent

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