Slow Release Of Size-controlled Aromatic Microcapsules And Their Knitted Fabric

Aromatic microcapsules improve the stability of the core material by coating a stable wall material around the essential oil material of the aromatic material core material,so as to release the fragrance for a long time.At present,it has been widely used in textile materials.SiO₂ nanoparticles are ultra-fine inorganic ions with small particle size,large specific surface area,high surface adsorption capacity,good stability and biocompatibility,and high thermal stability by coating essential oils The core material is then coated with the wall material to form essential oil microcapsules to increase the fragrance release time of the essential oil.In recent years,the research and application ofβ-cyclodextrin in microcapsules with good biocompatibility,non-toxicity,harmless to the skin,and good stability has attracted the attention of scholars.β-cyclodextrin can make use of intermolecular forces to embed essential oils in the cavity to form complex microcapsules,realize the coating of the core material,enhance the thermal stability of the core material,and improve the slow-release efficiency of the microcapsules.Since the particle size of the microcapsules has a certain impact on the sustained release performance of the microcapsules,this article controls the size of the two types of microcapsules.Lavender essential oil sponge-type mesoporous microcapsules and lavender essential oil/β-cyclodextrin complex microcapsules were prepared through single-factor experiments,and the factors affecting the particle size of the microcapsules were explored.In this paper,by comparing the preparation methods,particle size,encapsulation capacity and sustained release efficiency of the two microcapsules,the analysis shows that the preparation process of the lavender essential oil sponge-type mesoporous microcapsules is simple,the particle size is appropriate,and the encapsulation capacity is slow.The release efficiency is excellent.Therefore,the lavender essential oil sponge-type mesoporous microcapsules are integrated into the knitted fabric through the polyurethane lining method,so that the knitted fabric can release the fragrance for a long time.The specific content includes:（1）By comparing the two preparation methods of microcapsules,the particle size of the microcapsules was adjusted,and the effect of 1-3w.t.%SiO₂ nanoparticles and different stirring rates on the particle size of the microcapsules was studied.The effect of cyclodextrin wall material concentration,stirring rate,inclusion time,reaction temperature,core-wall ratio on the particle size of the complex,the encapsulation efficiency and slow-release performance are the main indicators,and the experimental parameters are optimized.（2）The microcapsules prepared by the in-situ polymerization method have better thermal stability and slow-release efficiency.The size of the core material can be adjusted by adjusting the concentration of SiO₂ nanoparticles and the emulsification rate,thereby adjusting the size of the microcapsules.The microcapsules are analyzed and characterized by optical microscope,scanning electron microscope,particle size analyzer,ultraviolet spectrophotometer,Fourier infrared spectrometer and thermogravimetric analyzer.The results show that:during the preparation process,when the concentration of SiO₂ nanoparticles is 2w.t.%and the emulsification rate is5000r/min,the resulting microcapsules have uniform particle size,good regularity,and a particle size of 12.5μm,the encapsulation capacity is 83.2%,and the fragrance lasts for 60 days and still has fragrance.（3）The prepared aromatic microcapsules are used as raw materials to construct a knitted fabric with the function of slow-release essential oils.The aromatic microcapsules and thermoplastic polyurethane are blended and calendered to prepare a patch,and then the prepared polyurethane directional retarded fragrance patch composite knitted fabric is prepared through a finishing process,Using VOC-detector and gas chromatograph to analyze the aromatic slow-release effect of knitted composite fabrics,and the designed products have broad application prospects when they are used in close-fitting underwear.