Homogeneous metal-organic frameworks (MOFs)-based optical thin films have attracted increasing attention, since they can potentially be used as active components in optical/opt-electrical devices, and how to fabricate MOF thin films with high quality is the premise of practically using them. Herein, five fabrication methods of MOF films are systematically investigated and compared from the aspects of appearance, reflectivity, micro-morphology, surface roughness, and optical properties of the films. The famous robust Zr-based MOF, UiO-66 (UiO = University of Oslo) is chosen as a model, and the five methods are spin-coating, dip-coating, self-assembly, direct growth, and the stepwise layer by layer growth method. This study provides fundamental support for the application of MOFs in the optical field.

The widely used catalysts for phthalonitrile (PN) resin polymerization are aromatic compounds containing –NH₂ because of their high catalytic performances. However, the catalytic mechanisms of these catalysts are not very clear. To understand the mechanisms of them, the widely used autocatalytic catalyst 4-(4-aminophenoxy)-phthalonitrile (4-APN) was studied in this paper. The polymerization process of 4-APN was tracked by a multi-purpose method, and ammonia gas was detected during the cross-linking processing for the fist time. Combined with the online IR results of the curing process of 4-APN, the mechanism of ammonia generation was newly proposed. Based on this mechanism, a new catalyst selection strategy was promoted, which is different from the traditional approach to catalyst selection for PN resin polymerization. According to the new strategy, 1,3-diiminoisoindoline (1,3-DII) was selected as a novel catalyst. The results showed that the new catalyst could not only effectively catalyze the polymerization of PN resin, but also has a lower curing temperature than that of organic amine catalysts and can eliminate the release of ammonia gas and the voids in the products caused thereby. Therefore, the results of this study will give important enlightenment to the development of PN catalysts and the development of PN.

There has been little research focus on the interface problems of phthalonitrile (PN) resin and carbon fiber. However, interface performance is related to the overall mechanical properties of composites and is very important. This study focused on the interfacial performance and adhesion mechanism of a carbon fiber C_f/PN composite. Micro-composites of C_f/PN and C_f/epoxy resins were prepared, and their interfacial shear strengths (IFSS) were tested by micro-droplet testing. The result showed that the IFSS of C_f/PN was higher than that of C_f/epoxy resin, indicating that the interfacial adhesion of the PN matrix composite must be more effective. To explain the obtained results, a number of tests, including SEM, SEM-EDS, FTIR, and TGA, were carried out. From the SEM analyses, cured PN polymer films were found on the surface of de-bonded carbon fibers. With the aid of SEM-EDS, the elements on the de-bonded carbon fiber surface of the C_f/PN composite were detected in situ. An interesting synchronous relationship was observed in the IFSS and SEM-EDS results. Through the FTIR spectra, the chemical structures of the PN polymers were identified. From the detailed analyses and discussion in this work, the effective interfacial bond function in the C_f/PN composite appears to be a complex result for all relative functions. The functional advantage of the PN composite may be the interface conjugation between the PN polymers and the graphene layer on the surface of the carbon fiber.

Inspired by concrete, a durable superhydrophobic nanocomposite coating is fabricated via an easy process.

Superhydrophobic nanocomposite coatings, prepared using adhesive and fillers, offer advantages including ease of fabrication and suitability for large-scale applications, but compared with other types of artificial superhydrophobic surfaces, poor durability still limits these surfaces from practical applications. The utilization of micro/nanoscale particles with both intrinsic hydrophobicity and robust mechanical properties to prepare coatings should significantly contribute to enhanced durability. Herein, rough and hydrophobic particles with micro/nano hierarchical structures were prepared at first, and robust superhydrophobic surfaces were fabricated using the prepared particles and additional nanoparticles. The initially prepared particles formed a rough framework of the coating, while additional nanoparticles provided inevitable nanoscale structures. A series of mechanical tests were carried out to validate the durability, and the surface with 20 wt.% NPs exhibited the best performance, withstanding 30 tape peeling tests, a 2.47 m sandpaper rubbing test (at a pressure of 5 kPa), the impact of 200 g of grit dropped from a height of 20 cm, and a 2 h acidic immersion. These appealing materials may attract attention for self-cleaning, high-speed water impact resistance, anti-icing, and anti-fouling applications in the coatings industry.