Learning in Hybrid-Project Systems: The Effects of Project Performance on Repeated Collaboration

This study advances contingency theories of performance-outcome learning in hybrid-project systems, in which both project participants and superordinate organizations influence the formation of project ventures. We propose that performance-outcome learning depends on the perceived relevance of prior performance and on organizational control over project participants. We examine this framework using data on 239 U.S. movie projects from the years 1931-40. In keeping with our theory, higher project performance led to future collaborations with the same partners, contingent on prior collaborations, project similarity, and organizational control. Our findings imply distinct patterns of network evolution and unfolding adaptation of hybrid-project systems through slow-moving, local adjustments

Oriented SBA-15-Type Silica Films on Polyimide Films with Laser-Induced Periodic Microgrooves

Oriented mesostructured silica films show potential for the design of nanostructured materials for applications in optics, electronics, and so on. In this report, we propose a new approach to control the orientation of mesochannels using a laser-modified polyimide surface. Pluronic 123 was employed as the structure agent, and mesostructured SBA-15-type silica film was prepared using dip- and spin-coating techniques. The orientation of the mesochannels was evaluated by in-plane X-ray diffraction (XRD) measurements. It was shown that the mesochannels were oriented along the surface microgrooves. The driving force for the orientation of the mesochannels is attributed to the confining effect of the surface microgrooves on the deposited mesochannels

Photosensitive Polymer from Ionic Self-Assembly of Azobenzene Dye and Poly(ionic liquid) and Its Alignment Characteristic toward Liquid Crystal Molecules

A new strategy based on ionic self-assembly technology was provided for design of photosensitive material as liquid crystals (LC) alignment layer. The complex material was constructed by the coupling of poly(ionic liquid) and photosensitive unit azobenzene dye methyl orange. The structure, phase behavior and photoresponse were examined by a variety of techniques including FTIR, NMR, thermal analysis, polarized optical microscopy, X-ray diffraction, small-angle X-ray scattering, and birefringence measurements. Highly ordered lamellar nanostructure and photosensitive character were confirmed. Under the irradiation of pulsed UV laser with certain fluences, a pronounced optical anisotropic surface with the preferred direction perpendicular to the pulsed polarization or regular periodic grooves microstructure surface parallel to the pulsed polarization was obtained. The anisotropic surface of oriented molecular chain or topography was demonstrated to result in the alignment of LC by the optical transmittance plot and polarizing microscopy images of LC cells with different rotation angles

Photosensitive Polymer from Ionic Self-Assembly of Azobenzene Dye and Poly(ionic liquid) and Its Alignment Characteristic toward Liquid Crystal Molecules

A new strategy based on ionic self-assembly technology was provided for design of photosensitive material as liquid crystals (LC) alignment layer. The complex material was constructed by the coupling of poly(ionic liquid) and photosensitive unit azobenzene dye methyl orange. The structure, phase behavior and photoresponse were examined by a variety of techniques including FTIR, NMR, thermal analysis, polarized optical microscopy, X-ray diffraction, small-angle X-ray scattering, and birefringence measurements. Highly ordered lamellar nanostructure and photosensitive character were confirmed. Under the irradiation of pulsed UV laser with certain fluences, a pronounced optical anisotropic surface with the preferred direction perpendicular to the pulsed polarization or regular periodic grooves microstructure surface parallel to the pulsed polarization was obtained. The anisotropic surface of oriented molecular chain or topography was demonstrated to result in the alignment of LC by the optical transmittance plot and polarizing microscopy images of LC cells with different rotation angles

A Facile Method to Prepare Macroscopically Oriented Mesostructured Silica Film: Controlling the Orientation of Mesochannels in Multilayer Films by Air Flow

A Facile Method to Prepare Macroscopically Oriented Mesostructured Silica Film: Controlling the Orientation of Mesochannels in Multilayer Films by Air Flo

Electrically Conductive PEDOT Coating with Self-Healing Superhydrophobicity

A self-healing electrically conductive superhydrophobic poly­(3,4-ethylenedioxythiophene) (PEDOT) coating has been prepared by chemical vapor deposition of a fluoroalkylsilane (POTS) onto a PEDOT film, which was obtained by electrochemical deposition. The coating not only maintained high conductivity with a low resistivity of 3.2 × 10^–4 Ω·m, but also displayed a water contact angle larger than 156° and a sliding angle smaller than 10°. After being etched with O₂ plasma, the coating showed an excellent self-healing ability, spontaneously regaining its superhydrophobicity when left under ambient conditions for 20 h. This superhydrophobicity recovery process was found to be humidity-dependent, and could be accelerated and completed within 2 h under a high humidity of 84%. The coating also exhibited good superhydrophobicity recovering ability after being corroded by strong acid solution at pH 1 or strong base solution at pH 14 for 3 h

Filter Paper with Selective Absorption and Separation of Liquids that Differ in Surface Tension

Superhydrophobic and superoleophilic filter paper was successfully prepared by treating commercially available filter paper with a mixture of hydrophobic silica nanoparticles and polystyrene solution in toluene. Applications of the filter paper in separating liquids with low surface tensions such as oil and ethanol from water were investigated in detail. The oil uptake ability of the superhydrophobic filter paper was evaluated and the results show that the filter paper can selectively adsorb oil floating on a water surface or in aqueous emulsions. Furthermore, filtration of mixtures of oil and water through the paper can reduce the water content in the oil. Additionally, the filter paper can also extract ethanol from homogeneous aqueous solution

Comprehensive Performance of Polyimide Reinforced by Multiple Hydrogen Bonds for Flexible Electronics Application

Multiple hydrogen bonds (multi-HBs) can not only realize supramolecular polymerization but also significantly improve the mechanical properties of materials. Although it is known that hydrogen bonding can strengthen polymeric properties, the effect of multi-HBs has not been explored for high-performance polymers, especially polyimides (PIs). Here, a diamine monomer capable of forming multi-HBs, N,N′-(6-oxo-1,6-dihydropyrimidine-2,5-diyl)-bis(4-aminobenzamide) (DAPyBA), has been successfully designed and synthesized, and corresponding PI films have been prepared by polymerization of DAPyBA and 4,4-diaminodiphenyl ether (ODA) at different molar ratios with pyromellitic dianhydride (PMDA). All the PI films exhibited excellent heat resistance, with glass transition temperatures (Tg) ranging from 354 to 397 °C and 5% weight loss temperatures (Td5) in the range from 455 to 574 °C. All the films also showed good mechanical properties and low coefficients of thermal expansion (CTE), and the mechanical properties and thermal dimensional stability of the PIs improved with increasing DAPyBA content due to the formation of multi-HBs. In particular, PI-50 presented a high tensile modulus (5.2 GPa), a low CTE (6.7 ppm K–1), and a high Tg (354 °C), meeting the requirements of the flexible electronics and flexible printed circuit board. Meanwhile, the introduction of DAPyBA can effectively increase the adhesion of PI films on substrates due to the high contents of N and O atoms therein