To improve the optical properties of polyimide (PI) films, we prepared two series of colorless transparent PIs from the dianhydride 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) and a diamine, either 2,2-bis(3-aminophenyl)hexafluoropropane (FDN) or 2,2-bis(3-amino-4-hydroxy-phenyl)hexafluoropropane (FDN-OH). Next, colorless PI (CPI) composite films were prepared by dispersing 0-1.00 wt % of organically modified clay (Cloisite 30B) in the intermediate poly(amic acid) (PAA) solution via solution intercalation, followed by imidization. The resultant CPI films had excellent optical transparency, which was achieved by reducing the charge-transfer effects by using a highly electronegative trifluoromethyl group and a kinked monomer structure. The thermal and mechanical properties, morphologies, and optical transparencies of the two as-synthesized CPI hybrid film series were investigated and compared. Electron microscopy observation of the two hybrid series revealed that the clay was well-dispersed with a nanoscale dispersion at all clay contents. However, agglomeration occurred at nanoclay loadings of 1.0 wt %. In addition, the effect of the presence of hydroxyl groups in the PI chain on various physical properties of the two CPI hybrids was also compared.
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http://dx.doi.org/10.1021/acsomega.1c02285 | DOI Listing |
Angew Chem Int Ed Engl
December 2024
Department of Chemistry and Shanghai Key Laboratory of Molecular, Catalysis and Innovative Materials, iChEM (Collaborative Innovation Center of Chemistry for Energy Materials), Fudan University, Shanghai, 200433, China.
Sn redox chemistry in aqueous acidic electrolyte was characterized with high reversibility and kinetics, which is considered as competitive anode material for aqueous batteries. Unfortunately, divalent Sn is unstable in aqueous electrolyte. It was revealed that Sn is easy to be oxidized to tetravalent Sn by dissolved oxygen and then forms precipitate through hydrolysis process, leading to serious performance decay.
View Article and Find Full Text PDFACS Appl Mater Interfaces
November 2024
Key Laboratory of Science & Technology of Eco-Textile, Jiangnan University, Ministry of Education, Wuxi, Jiangsu 214122, China.
Electro- and thermochromic materials have been greatly applied in smart windows and displays due to the excellent properties of color variation and solar radiation. However, the mono color and single response to voltage and temperature hinder their application and development. Here, a multimode dynamic color-changing device (T/ECD) was developed by integrating the electrochromic property of synthetic viologen dyes and the thermochromic properties of hydroxypropyl acrylate (HPA).
View Article and Find Full Text PDFChemSusChem
January 2025
Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo, 169-8555, Japan.
In the quest for eco-friendly optics, high refractive index polymers (HRIPs) with degradability have been one of the desirable optical materials for realizing eco-friendly and efficient lighting technologies. However, it has been challenging for HRIPs to simultaneously realize thermostability, high refractive index (RI), visible transparency, and efficient degradability, all of which are essential for their practical use. In this context, we herein focus on aromatic poly(dithioacetal)s, composed of visible-transparent yet degradable dithioacetal moieties and rigid phenylene sulfide spacers, exhibiting moderately high T (> 60 °C), high RI (> 1.
View Article and Find Full Text PDFDis Aquat Organ
September 2024
Institute of Veterinary Clinical Science, School of Veterinary Medicine, National Taiwan University, No. 153, Sec. 3, Keelung Rd., Da-an Dist., Taipei City 10672, Taiwan, ROC.
Septic arthritis is a frustrating disease in sea turtle rehabilitation because of its unclear pathogenesis, delayed onset during rehabilitation, long-term treatment requirements, and potentially poor prognosis. Radiography, blood cultures, and arthrocentesis have been used as diagnostic tools for suspected cases. However, there is currently a lack of data on the characteristics of synovial fluid in healthy sea turtles.
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