Fluorine-Free Transparent Superhydrophobic Nanocomposite Coatings from Mesoporous Silica

In recent decades, there has been a growing interest in the development of functional, fluorine-free superhydrophobic surfaces with improved adhesion for better applicability into real-world problems. Here, we compare two different methods, spin coating and aerosol-assisted chemical vapor deposition (AACVD), for the synthesis of transparent fluorine-free superhydrophobic coatings. The material was made from a nanocomposite of (3-aminopropyl)triethoxysilane (APTES) functional mesoporous silica nanoparticles and titanium cross-linked polydimethylsiloxane with particle concentrations between 9 to 50 wt %. The silane that was used to lower the surface energy consisted of a long hydrocarbon chain without fluorine groups to reduce the environmental impact of the composite coating. Both spin coating and AACVD resulted in the formation of superhydrophobic surfaces with advancing contact angles up to 168°, a hysteresis of 3°, and a transparency of 90% at 550 nm. AACVD has proven to produce more uniform coatings with concentrations as low as 9 wt %, reaching superhydrophobicity. The metal oxide cross-linking improves the adhesion of the coating to the glass. Overall, AACVD was the more optimal method to prepare superhydrophobic coatings compared to spin coating due to higher contact angles, adhesion, and scalability of the fabrication process

Trust Between International Joint Venture Partners: Effects of Home Countries

Trust is an important factor in interorganizational relations. Interorganizational trust in cross-border relationships is likely to be influenced by the home countries of both partners. Using data on 165 international joint ventures (IJVs), we show that the perceived trustworthiness of an IJV partner is influenced by the general propensity to trust in the trustor's home country. Moreover, the trustworthiness perceived by a focal parent firm is also affected by the home country of the other IJV partner. This second effect is mitigated by experience between the partners

Re-usable self-poled piezoelectric/piezocatalytic films with exceptional energy harvesting and water remediation capability

The need for sustainable technologies to address environmental pollution and energy crisis is paramount. Here we present a novel multifunctional nanocomposite, free standing films by combining piezoelectric molybdenum sulphide (MoS_{2}) nanoflower with poly vinylidene fluoride (PVDF) polymer, which can harness otherwise wasted mechanical energy for useful energy generation or water purification. The unique MoS_{2} nanoflower morphology is exploited to render the whole nanocomposite piezo active. A number of features are demonstrated to establish potential practical usage. Firstly, the nanocomposite is piezoelectric and piezocatalytic simultaneously without requiring any poling step (i.e. self-poled). Secondly, the self-poled piezoelectricity is exploited to make a nanogenerator to produce electrical power. The nanogenerator produced >80 V under human finger tapping with a remarkable power density, reaching 47.14 mW cm^{-3}. The nanocomposite film is made by simple solution casting, and the corresponding nanogenerator powers up 25 commercial LEDs by finger tapping. Last but not the least, the developed films show efficient, fast and stable piezocatalytic dye degradation efficiency (>90% within 20 min) against four different toxic and carcinogenic dyes under dark condition using only ultrasonic vibration. Reusability of at least 10 times is also demonstrated without any loss of catalytic activity. Overall, our nanocomposite has clear potential for use as self-powered sensor and energy harvester, and in water remediation systems. It should potentially also be deployable as a surface mounted film/coating in process engineering, industrial effluent management and healthcare devices systems