In this thesis, Cu₂O nanochains were synthesized by thermal decomposition with copper formate-octylamine as the precursor, oleic acid and oleylamine as the catalyst stabilizer agent and paraffin as the solvent. The phase structure and micromorphology of Cu₂O nanochains were characterized by X-ray diffraction and transmission electron microscopy. The effect of reaction time and concentration of the precursor on the Cu₂O nanochains were discussed, and the formation mechanism of the Cu₂O nanochains was analyzed. The results show that Cu₂O nanochains were self-assembled by Cu₂O nanocrystals; with the extension of the reaction time, Cu₂O nanochains gradually become granular; increasing the concentration of the precursor will increase the entanglement degree of the nanochains. Oleic acid contributes to the formation of Cu₂O, and oleylamine plays a directional role in the formation of nanochains. On the basis of those phenomenon, a comparison of the Cu₂O nanochain-water nanofluids with that of a water-based liquid showed that after irradiating for 3000 s, the temperature of nanofluids reached 91.1 °C while the water was only 75.7 °C. This demonstrates the better performance of the Cu₂O nanochain-water nanofluid in the ability of light absorption, thermal conductivity and photothermal conversion.

In this study, In-situ precipitation reaction was used to prepare paraffin@SnO₂/CNTs composite phase change materials. The paraffin@SnO₂/CNTs composites material were prepared by using paraffin as a phase change core material, and tin dioxide and carbon nanotubes as composite shell materials. The microstructure, chemical composition and crystal phase structure of the composites were analyzed by Scanning electron microscope (SEM), Fourier infrared spectrum (FT-IR) and X-ray diffraction (XRD). The thermal performance and thermal stability of phase change materials were determined by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The microcapsule has a core–shell structure with a diameter of 2–5 μm. The encapsulation efficiency of the paraffin@SnO₂/CNTs composite was calculated to be 42.94%. The slurry is formed by dispersing microcapsules in water, which not only greatly improves the specific heat capacity, thermal conductivity, visible light absorption, but also makes the effective receiving efficiency reach 91.79% at 40 °C, indicating that it is a promising heat transfer working slurry in the field of Direct Absorption Solar Collectors (DASC) system.

This article reports the design and manufacture of colored microcapsules with specific functions and their application in architectural interior wall coating. Utilizing reactive dyes grafted SiO₂ shell to encapsulate paraffin through interfacial polymerization and chemical grafting methods, this experiment successfully synthesized paraffin@SiO₂ colored microcapsules. The observations of surface morphology demonstrated that the colored microcapsules had a regular spherical morphology and a well-defined core-shell structure. The analysis of XRD and FT-IR confirmed the presence of amorphous SiO₂ shell and the grafting reactive dyes, and the paraffin possessed high crystallinity. Compared with pristine paraffin, the thermal conductivity of paraffin@SiO₂ colored microcapsules was significantly enhanced. The results of DSC revealed that the paraffin@SiO₂ colored microcapsules performed high encapsulation efficiency and desirable latent heat storage capability. Besides, the examinations of UV-vis and TGA showed that the paraffin@SiO₂ colored microcapsules exhibited good thermal reliability, thermal stability, and UV protection property. The analysis of infrared imaging indicated that the prepared latex paint exhibited remarkable temperature-regulated property. Compared with normal interior wall coatings, the temperature was reduced by about 2.5 °C. With such incomparable features, the paraffin@SiO₂ colored microcapsules not only appeared well in their solar thermal energy storage and temperature-regulated property, but also make the colored latex paint coating have superb colored fixing capabilities.

As a renewable, environmentally friendly, natural, and organic material, wood has been receiving extensive attention from various industries. However, the hydrophilicity of wood significantly impacts the stability and durability of its products, which can be effectively addressed by constructing superhydrophobic coatings on the surface of wood. In this study, tung oil, carnauba wax, and silica nanoparticles were used to construct superhydrophobic coatings on hydrophilic wood surfaces by a facile two-step dip-coating method. The surface wettability and morphology of the coatings were analyzed by a contact angle meter and scanning electron microscope, respectively. The results suggest that the coating has a micron–nanosized two-tiered structure, and the contact angle of the coating is higher than 150° and the roll-off angle is lower than 10°. Sandpaper abrasion tests and UV diffuse reflectance spectra indicate that the coatings have excellent abrasion resistance and good transparency. In addition, the coated wood shows excellent self-cleaning and water resistance, which have great potential for applications in industry and furniture manufacturing.

We report luminous polylactic acid (PLA) composite prepared via a solvent casting method using different amounts of phosphor strontium aluminate (SrAl₂O₄: Eu²⁺ and Dy³⁺) (SAO). The reason for doing this is that the changes of fluorescence and mechanical properties in the composites with different SAO contents can be directly evaluated. The SAO particles should have a variety of excellent characteristics in the PLA matrix, among which dispersibility and compatibility are particularly important; so, they can be modified by 3-aminopropyltriethoxysilane (APS) to achieve the target characteristics. The results showed that the fluorescence and mechanical properties were affected by SAO addition. The mechanical properties significantly improved with 5wt SAO; further, addition had no impact. And the emission band of fluorescence and phosphorescence is just at the peak of 524nm. The composites with 15wt SAO have the best fluorescence properties. The fluorescence decreased with further doping. Fluorescence decay curves with various amounts of SAO particles show a similar tendency as pure SAO particles; the speed of decrease in afterglow intensity was higher for the first 30min. In addition, the detailed morphological scanning and study by scanning electron microscope (SEM) showed that the particles had good adhesion to the matrix. In conclusion, the concentration of SAO into the PLA matrix impacts the fluorescence and mechanical properties of a SAO/PLA composite material.

In this study, SiO₂/polymer co-coated colored aluminum pigment was prepared by sol-gel method and atom transfer radical polymerization technique. The results of scanning electron microscope (SEM) and transmission electron microscope (TEM) analysis showed that there was a coating layer with the thickness of about 500 nm on the surface of the pigment. X-ray diffraction (XRD) and fourier transform infrared spectroscopy (FT-IR) analysis revealed that the coating layer of the pigment contained SiO₂ and polymer of 2-(Dimethylamino)ethyl methacrylate (DMAEMA), indicated that SiO₂ and the polymer were successfully coated on the surface of the aluminum powder. Moreover, the co-coated layer of SiO₂ and the polymer can effectively prevent the contact between the aluminum powder and the corrosive medium, thereby exhibiting excellent corrosion resistance. In addition, the prepared pigment was made into a pigment paste in a certain ratio and uniformly coated on a polyester fabric, its UPF value was 93.03, which revealed that the coated fabric has excellent ultraviolet protection properties.