Transparent Aluminium Oxide Coatings of Polymer Brushes

Abstract

A novel method for the preparation of transparent Al2O3 coatings of polymers is presented. An environmental-friendly sol-gel method is employed, which implies mild conditions and low costs. A thermoresponsive brush is chosen as a model surface. X-ray photoelectron spectroscopy is used to characterize the samples during the conversion of the precursor Al(OH)3 into oxide and to prove the mildness of the protocol. The study evidences a relation between lateral homogeneity of alumina and the wettability of the polymer surface by the precursor solution, while morphology and elasticity are dominated by the polymer properties. The study of the swelling behavior of the underneath brush reveals the absence of water uptake, proving the impermeability of the alumina layer. The broad chemical and structural variety of polymers, combined with the robustness of transparent alumina films, makes these composites promising as biomedical implants, protective sheets and components for electric and optical devices.

Functional nano‐fillers in waterborne polyurethane/acrylic composites and the thermal, mechanical, and dielectrical properties

“…These suggest that the addition of nano aluminum oxide into PUA may increase the transparency and broaden the light selectivity of the film. It may arise from the high optical transmittance of alumina and the compactly stacked nanoparticles of the composite (as shown in Figure 4(d)), in which the aluminum oxide nanoparticles may fill the opaque positions in PUA matrix to enhance the transparence 46 . The transparency of sample P1 and P3 is the almost the same, indicating that the CNCs nanofiller has little impact on transparency of PUA film.…”