scholarly journals Hard Coating Materials Based on Photo-Reactive Silsesquioxane for Flexible Application: Improvement of Flexible and Hardness Properties by High Molecular Weight

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1564
Author(s):  
Jong Tae Leem ◽  
Woong Cheol Seok ◽  
Ji Beom Yoo ◽  
Sangkug Lee ◽  
Ho Jun Song
Keyword(s):  
Molecular Weight ◽  
Surface Morphology ◽  
High Molecular Weight ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Coating Materials ◽  
Pencil Hardness ◽  
Coated Film ◽  
Flexible Application

EPOSS of polyhedral oligomeric silsesquioxanes (POSS) mixture structure and LPSQ of ladder-like polysilsesquioxane (LPSQ) structure were synthesized via sol–gel reaction. EPSQ had a high molecular weight due to polycondensation by potassium carbonate. The EPSQ film showed uniform surface morphology due to regular double-stranded structure. In contrast, the EPOSS-coated film showed nonuniform surface morphology due to strong aggregation. Due to the aggregation, the EPOSS film had shorter d-spacing (d1) than the EPSQ film in XRD analysis. In pencil hardness and nanoindentation analysis, EPSQ film showed higher hardness than the EPOSS film due to regular double-stranded structure. In addition, in the in-folding (r = 0.5 mm) and out-folding (r = 5 mm) tests, the EPSQ film did not crack unlike the EPOSS coated film.

Nano- and Micro-Structural Evolution of UHMWPE by Ion Beam

2007 ◽  
Vol 1020 ◽  
Author(s):  
F. Calzzani ◽  
B. Chhay ◽  
R. Zimmerman ◽  
A. Oztarhan ◽  
D. Ila
Keyword(s):  
Molecular Weight ◽  
Surface Morphology ◽  
High Molecular Weight ◽  
Chemical Structure ◽  
Ion Beam ◽  
Aerospace Industry ◽  
Structural Evolution ◽  
Before And After ◽  
Polyethylene Devices ◽  
Ultra High Molecular Weight

AbstractIt is important to produce uniform nano-patterns with no possibility of surface exfoliation on polyethylene devices used in medical and in aerospace industry. We studied the change in the surface morphology of polyethylene at nanoscale using MeV ion beam. We have investigated the change in the surface morphology before and after ion bombardment. We have made an attempt to change the morphology to produce a uniform surface with reduced cracks and reduced granularity. For this process we have chosen ultra-high-molecular-weight polyethylene (UHMWPE). Coupons of these materials were exposed to various fluences of MeV Ag+ ions. The surface morphology and the change in the chemical structure were studied using scanning micro Raman, FTIR and AFM.

Viscoelastic behavior of high molecular weight polyimide/cyclohexanone solution during sol-gel transition

Polymer ◽  
2020 ◽  
Vol 190 ◽  
pp. 122250
Author(s):  
Hongxiang Chen ◽  
Wei Liu ◽  
Mei Hong ◽  
Ensong Zhang ◽  
Xuemin Dai ◽  
...  
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Sol Gel ◽  
Viscoelastic Behavior ◽  
Sol Gel Transition ◽  
Gel Transition

Structural and Optical Characterization of TiO2/ZnO Thin Films Prepared by Sol-Gel Method

2017 ◽  
Vol 888 ◽  
pp. 290-296
Author(s):  
Nur Syahraain Zulkiflee ◽  
Rosniza Hussin ◽  
Hasrul Yahya
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Optical Properties ◽  
Surface Morphology ◽  
Calcination Temperature ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Zno Thin Films ◽  
Gel Method ◽  
Sol Gel Method

Thin film has been extensively study due to better structural, surface morphology, and optical properties. The combination of two materials will enhance the properties of thin film. In this study, TiO2/ZnO thin films were deposited on glass substrates via sol-gel method. TiO2 acts as pre-deposited thin film with calcination temperatures at 400 °C, 500 °C, and 600 °C. The post-deposition of TiO2/ZnO thin films were calcined at 500 °C and 600 °C. TiO2 sol-gel was synthesis from titanium (IV) butoxide and butanol as the precursor, while ZnO sol-gel was synthesis from zinc acetate dehydrate and isopropanol as the precursor. The TiO2/ZnO thin films were characterized by X-ray diffraction (XRD), atomic force microscope (AFM), and ultraviolet visible spectroscopy (UV-Vis). The effect of calcination temperature and pre-deposited TiO2 thin films show difference results of bilayer thin films. The XRD analysis shows all TiO2/ZnO thin films growth with TiO2 anatase crystalline phase at orientation (1 0 1) and ZnO zincite phase at orientation (1 0 1). The structural properties of TiO2/ZnO thin films were improved by controlling the calcination temperature. Based on AFM analysis, the RMS value for TiO2/ZnO decreases as the calcination temperature increased. The compacted and dense surface roughness were controlled by the temperature. Meanwhile, the percentage of thin film ultraviolet transmittance can be enhanced with combination of two materials, TiO2 and ZnO. Therefore, the pre-deposited layer of thin film with influenced by calcination temperature will improve the crystallinity, surface morphology, and optical properties of TiO2/ZnO thin films.

Synthesis of 2-methylacrylamide/high-molecular-weight Cellulose for Removing Anionic Dyes from Water by Irradiation with Gamma Rays

2021 ◽  
Author(s):  
Shuaifeng Zhang ◽  
Jun Gu ◽  
Baochao Fan ◽  
Li Li ◽  
Bin Li
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Sol Gel ◽  
Zero Point ◽  
Raw Material ◽  
Anionic Dyes ◽  
Cellulose Aerogel ◽  
Ph Range

Abstract We report a new method for treating high-molecular-weight cellulose with 60Co gamma rays to simultaneously graft functional groups onto the natural polymer and promote its solubility. After exposing cellulose to a 40-kilogray dose of gamma rays in the presence of 2-methylacrylamide, numerous amide groups were grafted onto the cellulose chain and its solubility increased markedly. Amide-functionalized aerogels were prepared via the sol-gel method using the irradiated product as a raw material. Compared with 40-kGy-irradiated cellulose aerogel, the amide-functionalized aerogels had relatively high zero-point charge pH values and excellent adsorption capacities with regard to anionic dyes over the pH range 2-10. They were also stable in terms of reusability. Therefore, the 2-methylacrylamide/high-molecular-weight cellulose aerogel has great potential for use in the treatment of colored surface wastewater. The 60Co gamma ray irradiation technique described herein is a flexible, stable and highly efficient method for the preparation of functionalized cellulose products.

Increasing inter-yarn friction to ultra-high molecular weight polyethylene yarns for ballistic application by sol-gel treatment

2020 ◽  
pp. 152808372094296
Author(s):  
Yanyan Chu ◽  
Riazur Rahman ◽  
Haonan He ◽  
Weihan Huang ◽  
Xiaogang Chen
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Performance Test ◽  
Sol Gel ◽  
Friction Test ◽  
Ballistic Performance ◽  
Ballistic Protection ◽  
Gel Treatment ◽  
The Coefficient Of Friction ◽  
Ultra High Molecular Weight

Ultra-high molecular weight polyethylene fibre is popularly used in military for ballistic protection owing to its low density but high modulus and high tenacity. However, the inter-yarn friction in the corresponding ballistic fabric is too low and thus the yarns in the fabric are easily pulled out, in which lowers down the ballistic performance. This paper aims to improve the inter-yarn friction in the fabric by sol-gel method using TiO2/ZnO hydro-sols and investigate the ballistic performance of fabric treated. The results from the coefficient of friction test have showed that the inter-yarn friction treated with TiO2/ZnO hydro-sol can be increased 40%. Moreover, tensile test indicates that the tenacities of yarns after different treatments are increased whereas the strains and moduli of the yarns almost kept unaffected. Through ballistic performance test, the treated fabric displays higher ballistic energy absorption compared with the original one, indicating that higher inter-yarn friction is beneficial to fabric against ballistic impact.

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