Enhanced antistatic and solvent resistant polycarbonate blends: Fabrication and characterization

This study presents the development of advanced antistatic and solvent resistant polycarbonate blends by incorporating antistatic agents (AAs) into bisphenol A-type polycarbonate (PBPA) and polycarbonate-polysiloxane copolymer (P-Si). A straightforward one-step melt blending was employed to fabricate PBPA/P-Si/AA blends. Comprehensive characterization methods, including Fourier-transform infrared spectroscopy (FT-IR), optical microscope, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and both tensile and impact tests were deployed to study the structure, morphology, thermal, and mechanical behaviors of the synthesized blends. The results demonstrated effective mixing of PBPA and P-Si. The T_g of PBPA/P-Si/AA blends is decreased relative to PBPA, because the chain flexibility of the blends will be increased after adding AA, which is reflected in the impact strength and elongation at break of PBPA/P-Si/AA blends. On the other hand, the thermal stability of PBPA/P-Si/AA is reduced relative to PBPA. The most significant result is that the resistance of the blends to ethyl acetate is enhanced. This is because the addition of P-Si to the matrix introduces a high bonding energy Si O bond, which makes PHBPA/P-Si less prone to detachment and cracking and swelling when exposed to ethyl acetate. While improving the solvent resistance, the blends also have excellent antistatic property, only the concentration of AA is increased to 6 wt.%, and the surface resistance of PBPA/P-Si/AA is reduced from 10⁶ GΩ to only 1 GΩ. This dramatic decrease is a result of the widespread distribution of the positive charge of the ammonium ion throughout the material, promoting the formation of a continuous conductive network within the matrix and thereby enhancing conductivity. In conclusion, this study offers valuable insights into improving the solvent resistance and antistatic characteristics of polycarbonate blends.     

Optical properties and cooling performance analyses of single-layer radiative cooling coating with mixture of TiO2 particles and SiO2 particles

Radiative cooling can achieve cooling effect without consuming any energy by delivering energy into outer space(3K) through"atmospheric window"(8–13 μm). Conventional radiative cooling coating with multi-layer structure was severely restricted during application due to its complex preparation process and high cost. In this study, a single-layer radiative cooling coating with mixture of TiO_2 particles and SiO_2 particles was proposed. The algorithm for calculating the radiative properties of the multi-particle system was developed. Monte Carlo ray-tracing method combined with that algorithm was used to solve the radiative transfer equation(RTE) of the single-layer radiative cooling coating with mixture of TiO_2 particles and SiO_2 particles.The effects of particle diameter, volume fraction and coating thickness on radiative cooling performance were analyzed to obtain the best radiative cooling performance. The numerical results indicated that the average reflectivity of the single-layer radiative cooling coating with mixture of TiO_2 particles and SiO_2 particles in the solar spectrum can reach 95.6%, while and the average emissivity in the "atmospheric window" spectrum can reach 94.9% without additional silver-reflectance layer. The average reflectivity in the solar spectrum and average emissivity in the "atmospheric window" spectrum of the single-layer radiative cooling coating with mixture of TiO_2 particles and SiO_2 particles can increase 4.6% and 4.8% compared to the double-layer radiative cooling coating. This numerical research results can provide a theoretical guidance for design and optimization of single-layer radiative cooling coatings containing mixed nanoparticles.