Functional copolymer coatings on electrospun fibers via photo-initiated chemical vapor deposition

With the increasing use of implantable patches in biomedical applications, the significance of surface modification techniques in improving biocompatibility, enhancing adhesion, and regulating drug release has grown. A significant challenge that these methods must address is ensuring that the process does not harm the delicate fibers or therapeutic agents they contain. Here, we report surface functionalization of implantable, curcumin loaded Polycaprolactone (PCL) patches with pH-responsive poly(2-hydroxyethyl methacrylate-co-4-vinylpyridine), p(HEMA-co-4VP) polymer thin film. The polymer was coated on the patch surface via photo-initiated chemical vapor deposition (piCVD) where the polymerization was initiated by the UV degradation of the initiator tert-butyl peroxide (TBPO) and the monomer HEMA. Additionally, the piCVD method was utilized to crosslink the HEMA without the use of additional crosslinkers. The pH-responsiveness of the coating was achieved by incorporating 4VP into the copolymer structure. The effect of the coating was demonstrated through degradation and drug release studies. The presence of the polymer coating decelerated the fiber degradation and the pH-dependent swelling of the coating allowed for the control of drug release rates from the patches. The innovative use of piCVD as a coating method provides a platform for advancing tailored surface modifications in various biomedical applications

Upcycled graphene integrated fiber-based photothermal hybrid nanocomposites for solar-driven interfacial water evaporation

Solar-driven interfacial evaporation is an efficient and viable solution for providing freshwater, especially in remote areas that utilize sunlight for water purification and desalination systems. This study proposes a practical preparation method for a photothermal nanocomposite, compromising Polyacrylonitrile (PAN) nanofibrous membrane, crosslinked PVA, and upcycled Graphene Nanoplatelets (GNP). The synergistic effect between the PAN nanofibers and PVA/GNP nanocomposite and the contributing factors to the overall performance is examined. It was found that the initial thickness of the PAN nanofibrous layer has an inverse effect on the evaporation rate. The obtained results indicated that while the GNP content enhances the photothermal activity, it deteriorates the water absorbency of the nanocomposite; thus, an optimized concentration should be obtained. By investigating different parameters for the evaporator, we obtained an evaporation rate of 1.40 kg/m2h under 1 sun of illumination