In this study, instead of using the usual chemical methods, poly(butyl acrylate)/silicon dioxide (PBA/SiO) core-shell composite microspheres were prepared using a physical method-ultrasonically initiated encapsulation emulsion polymerization. The morphology and particle size of the PBA/SiO microspheres were analysed using transmission electron microscopy (TEM) and dynamic light scattering (DLS). The encapsulation state was determined using X-ray photoelectron spectroscopy (XPS). The composition and thermogravimetric behavior were characterized using Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The TEM and DLS results show that monodisperse PBA/SiO core-shell composite microspheres were successfully obtained. The diameter and shell thickness were 150 nm and 15 nm, respectively. The XPS and FTIR results show that there was no new chemical bond between the PBA shell and the SiO core. They were just combined by physical adsorption. The encapsulation efficiency of SiO microspheres by PBA is 8.2% through TGA. In addition, this article focuses on the formation mechanism of PBA/SiO core-shell microspheres prepared through ultrasonically initiated encapsulation emulsion polymerization. Intuitive observation and the results of TEM and DLS, especially the change in zeta potential, clearly indicate an encapsulation process. Thereinto, a bilayer-structure space established by appropriate amount of cetyltrimethyl ammonium bromide (CTAB) molecules is the key to realize ultrasonically initiated encapsulation emulsion polymerization.

In this study, stearic acid suitable for thermal energy storage applications was nanoencapsulated in a poly(methyl methacrylate) shell. The nanocapsules were prepared using a simple ultrasonically initiated in situ polymerization method. The morphology and particle size of the poly(methyl methacrylate)/stearic acid phase change energy storage nanocapsules (PMS-PCESNs) were analyzed using transmission electron microscopy, scanning electron microscopy, atomic force microscopy and dynamic light scattering. The latent heat storage capacities of stearic acid and the PMS-PCESNs were determined using differential scanning calorimetry. The chemical composition of the nanocapsules was characterized using Fourier transform infrared spectroscopy. All of the results show that the PMS-PCESNs were synthesized successfully and that the latent heat storage capacity and encapsulation efficiency were 155.6 J/g and 83.0%, respectively, and the diameter of each nanocapsule was 80-90 nm.

In the research, bovine serum albumin/astragalus membranaceus oil (BSA/AM) core‐shell microcapsules were prepared using the sonochemical method. The energy provided by ultrasound was used to initiate the cross‐linking reaction of the sulfhydryl groups of cysteine residue in BSA to form a disulfide bond, thereby encapsulating the core material‐AM. The core‐shell structure and morphology of the BSA/AM microcapsules were confirmed by transmission electron microscopy (TEM) and scanning electron microscopy (SEM), respectively. The microcapsule size was determined by dynamic light scattering (DLS). The composition and loading rate of AM were characterized through Fourier transform infrared spectroscopy (FT‐IR) and thermogravimetric analysis (TGA). The hardness and Young's modulus were measured using nanoindentation. And the release performance of BSA/AM microcapsules was investigated by ultraviolet‐visible spectrophotometer (UV‐Vis). The TEM and SEM results show that the BSA/AM microcapsules are spherical with a narrow size distribution. A core‐shell structure and a smooth microcapsule surface were clearly observed. The DLS results show that the microcapsules size and shell thickness are ca. 300 nm and 40 nm, respectively. The FT‐IR results indicate that the shell was formed by denaturing the cross‐linking of BSA under ultrasonic irradiation conditions. The loading rate of AM, approximately 67.6 %, was calculated by TGA. Based on nanoindentation, the hardness and Young's modulus are 0.0107 GPa and 0.1477 GPa, respectively. In terms of the release performance, all astragalus membranaceus oil can be almost released during the time period of four hours.

Using nanoencapsulated phase change materials (NanoPCMs) for thermal energy storage have great application prospects in addressing the mismatch issues between energy supply and demand. However, the rapid, large-scale preparation of...