Self-Wrinkling Patterned Surface of Photocuring Coating Induced by the Fluorinated POSS Containing Thiol Groups (F-POSS-SH) as the Reactive Nanoadditive

We here demonstrate a facile approach of one-step to obtain the complex wrinkling patterned surface of the photocuring coating by using thiol and fluorocarbon chains containing POSS (F₂-POSS-SH₆) as reactive nanoadditive. F₂-POSS-SH₆ can self-assemble into the top layer of the UV-curing liquid resin. As a result, the mismatch of shrinkage caused by the different types of photo-cross-linking reaction between the top layer and bulk layer leads to formation of the wrinkling pattern. The characteristic wavelength (λ) and amplitude (<i>A</i>) are linearly dependent on the concentration of F₂-POSS-SH₆. The resulting surface exhibits superlow surface energy (4.1 mN/m) when the concentration of F₂-POSS-SH₆ is only 1%. The feasibility and generality of this approach for the excellent hydrophobic and oleophobic surface will undoubtedly find practical application in photocuring coating with functions such as self-cleaning

Polymerization-Induced Growth of Microprotuberance on the Photocuring Coating

Surface pattern on the nano- and microscale is of great interest due to its special optical effect, which might find potential application in optical devices such as LCD display, packaging of LED chip, and thin-film solar cell. We here developed a facile bottom-up approach to fabricate microprotuberance (MP) on surface by using curable resin via sequential photocuring at room temperature and thermal polymerization at high temperature. The curable resin is composed of random fluorinated polystyrene (PSF) as blinder and trimethylolpropane trimethacrylate (TMPTA) as cross-linker. The polymerization of TMPTA during the annealing process at high temperature induces phase separation between the PSF and TMPTA cross-linked network, resulting in the extrusion of PSF and the formation of protuberance on the surface. The formation mechanism of MP was studied in detail by investigating the effect of annealing time, temperature, thickness of film, and PSF on the size and morphology. MPs with size from one to tens of micrometers were fabricated through this one-pot strategy. Moreover, encapsulation of integrated GaN/InGaN-based LED chip by the cross-linked coating with MP can enhance the light extraction efficiency and light diffusion obviously

Simultaneous Formation of a Self-Wrinkled Surface and Silver Nanoparticles on a Functional Photocuring Coating

Bioinspired functional surface with micro/nanostructures are particularly attractive because of the potential for outstanding characteristics, such as self-cleaning, self-replenishing and antibiosis. Here, we presented a facile approach to fabricate a functional photocuring coating with both a self-wrinkling patterned surface and incorporated silver nanoparticles (Ag NPs). Fluorinated polymeric photoinitiator (FPPI) and silver precursor (TFAAg) can self-assemble together on the air/acrylate interface to form a top layer of photocuring liquid resin. Under UV irradiation, a wrinkled pattern was formed as a result of the mismatch in shrinkage caused by photopolymerization between the top layer and the bulk layer. Simultaneously, Ag NPs with sizes of 15 ± 8 nm in diameter were in situ generated in the photocuring coating through the photoreduction of TFAAg. Their number density is higher in the top layer than in the bulk. Scanning electron microscope (SEM) and atomic force microscope (AFM) measurements revealed that the characteristic wavelength (λ) and amplitude (<i>A</i>) of the wrinkled morphology increased with growing concentration of FPPI, and that the generation of Ag NPs led to the wrinkle-to-fold transition. Furthermore, the obtained functional coatings possess a low surface energy and self-replenishing and antibiosis capabilities as a result of the synergistic effect of the wrinkled surface covered by FPPI and Ag NPs