Microencapsulation of Photochromic Solution with Polyurea by Interfacial Polymerization

Abstract

Photochromic materials are interesting materials because of their color-changing property under UV light and visible light irradiation. However, they are vulnerable to many factors, such as pH oxygen, ion, solvent, etc. because of the unsaturated bonds existing on the photochromic molecular. Microencapsulation of the photochromic materials can separate them from the surroundings. Here, photochromic microcapsules using 3,3-Diphenyl-3H-naphtho[2,1-b] pyran (NP)/solution as core and polyurea as shell via interfacial polymerization were prepared, and bis(2,2,6,6-tetramethyl-4-piperidinyl)sebacate (HALS 770) was used as photostabilizer. Fourier transform infrared spectroscopy (FTIR), a laser particle size analyzer, a scanning electron microscope (SEM), a thermogravimetric analyzer and an ultraviolet-visible spectrophotometer were used for characterization. The results showed that the microcapsules had a uniform particle size of about 0.56 μm when the percentage of the oil phase (core) in the emulsion was less than 15%, the addition amount of the emulsifier was 0.4%, and the stirring rate was 1800r/min. The microcapsules showed better performance in thermal stability when the core/shell ratio was 1:1. The photostabilizer had little impact on the color-changing property of the microcapsule, but it could protect the microcapsules from UV light radiation aging.

Microencapsulation for Pharmaceutical Applications: A Review

“…Polymerization is to produce protective microcapsule coatings in situ, by reactions of monomeric units located at the interface between a core material and a continuous phase in which the core material is dispersed. − The continuous (or core material supporting) phase is usually a liquid or gas, and thus the polymerization reactions happen at a liquid–gas, liquid–liquid, solid–gas, or solid–liquid interface. − Microcapsules made by interface polymerization have been successfully used in pharmaceutical over the past few decades. , For interfacial polymerization, an emulsion is formed from the two phases: oil and aqueous. Each phase contains a reacting monomer: one of the reacting monomers is dissolved in the oil phase, and the other reacting monomer is dissolved in the aqueous phase.…”

Preparation of Photochromic Microcapsules of Poly(methyl methacrylate)/Inorganic Metal Oxide Composite Shells with UV‐Resistant Properties and Application to Printing on Cotton Fabrics

“…Zhang et al prepared a urea-formaldehyde shell material-coated spiropyran-based photochromic microcapsules by interfacial polymerization, which showed that the microcapsules were thermally stable and the addition of light stabilizers in the shell material did not have a significant effect on the discoloration performance of the microcapsules, but it had a good effect on the enhancement of UV-resistance and antioxidant aging of the microcapsules. [21] Zhao et al prepared a phase change microcapsule doped with inorganic nano-modified particles in the organic shell material matrix material by cross-linking the modified TiO 2 to the reticulation of PMMA, and the results showed that the microcapsules exhibited stable UV-shielding performance. [22] In this study, we prepared UV-resistant functional microcapsules of crosslinked modified TiO 2 nanoparticles and hybridized ZnO nanoparticles in shell material, respectively.…”

Photochromic performance optimization of polyurethane microcapsules by interfacial polymerization method

“…Multi‐color photochromic microcapsules are synthesized via interfacial polymerization based on the subtractive principle 2 . A photochromic solution with HALS 770 added as the light stabilizer is microencapsulated through interfacial polymerization, and the absorption of the microcapsules shows no obvious decline after 15 days of the UV accelerated aging test 20 . However, reports of the influence factors on the photochromic property among process parameters in the microencapsulation process of the interfacial polymerization method remain a vacancy.…”

“…2 A photochromic solution with HALS 770 added as the light stabilizer is microencapsulated through interfacial polymerization, and the absorption of the microcapsules shows no obvious decline after 15 days of the UV accelerated aging test. 20 However, reports of the influence factors on the photochromic property among process parameters in the microencapsulation process of the interfacial polymerization method remain a vacancy. The most widely developed photochromic microcapsule shell materials are chitosan, polyurea, polyurethane, and polymethyl methacrylate.…”