Water resistance and luminescent thermal stability of SiO2 coated phosphor and self-luminous cement-based materials: View from the perspective of hydration balance

2022 ◽  
Vol 319 ◽  
pp. 126086
Author(s):  
Wentong Wang ◽  
Aimin Sha ◽  
Xinzhou Li ◽  
Fan Zhang ◽  
Wei Jiang ◽  
...  
2013 ◽  
Vol 395-396 ◽  
pp. 367-370
Author(s):  
Cai Hua Gao ◽  
Wen Lu Guo ◽  
Zhi Ming Jin

The acrylic emulsion adhesive was modified by D4 and KH570 with chemical process, and we can get the modified product successfully via the best technology parameter which was confirmed by orthogonal experiment. The structure of acrylic was characterized by FTIR, while there was a comparative study on the macroscopic properties and thermal stability of the unmodified and modified product. The results showed that when m(D4):m(KH570) was 2:1, the dosage of emulsifier was 3.0%, the dosage of KPS was 4.0%, the monomer(soft and hard) ratio was 1:1, the stability of the acrylic emulsion adhesive modified by double siloxane was good, and its viscosity, water resistance, heat resistance were improved greatly.


2013 ◽  
Vol 690-693 ◽  
pp. 1577-1580
Author(s):  
Xiao Xi Hu ◽  
Yun Wang

A serious of silane-terminated poly (urethane-imide) (Si-PUI) was synthesized via prepolymer method using polycarbonatediols (PCDL), 2,4-tolylene diisocyanate (TDI), 4,4'-Oxydiphthalic Anhydride (ODPA) and silane coupling agent KH-550. The structure of the products was characterized by FT-IR. The thermal properties were measured by thermal gravimetric analysis (TGA). The thermal mechanical behavior was investigated by dynamic mechanical analysis (DMA).The mechanical characteristic was measured by tensile tests. The water absorption (Wa) was also been tested. With the imide content increasing, the thermal stability, tensile strength and storage modulus of poly (urethane-imide) improve significantly, and the glass transition temperature rises. The introduction of silanes improves the water resistance and further enhances the thermal stability of poly (urethane-imide).


e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Qun Wang ◽  
Lu Qi

AbstractA group of films mainly composed of sericin and poly(vinyl alcohol) (PVA), using boric acid (BA) as a modifier, were prepared by a technique of solution casting. In this work, the effect of BA and sericin on the mechanical properties and water resistance of the films was analyzed, the interior morphology of the films were described by a scanning electron microscopy (SEM), the thermal stability of the films was characterized by differential scanning calorimetry (DSC), and the reaction mechanism was proposed according to the previous literature and the test of Fourier transform infrared spectrum (FTIR). Results indicated that, the properties of the membrane were the functions of the blend ratio of sercin to PVA and the content of BA. The use of BA increased the tensile strength, improved the water resistance and the thermal stability, and varied the interior morphology of the films. The content of sericin greatly influenced the combination of properties of the films, especially the mechanical properties, interior morphology, thermal stability, and water resistance reducing with the increasing of sericin content. The films have potential to be used in materials, such as skin-care coatings for beauty, percutaneous drug delivery systems for exterior intact skin, due to the characteristics of the components and the good mechanical properties of the films.


Forests ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 726
Author(s):  
Runhao Liu ◽  
Xinyao Liu ◽  
Yuting Zhang ◽  
Junjia Liu ◽  
Chengxi Gong ◽  
...  

Wax impregnation is an effective approach to improve wood water resistance. However, melted waxes require special equipment and cannot penetrate deep enough into wood. Recently, wax emulsions show excellent efficiency in wood modification. In this study, paraffin Pickering emulsion stabilized by low dispersed SiO2 nanospheres was used to impregnate poplar wood. The microstructure and storage stability of the emulsion were evaluated. The dimensional stability, water uptake, wettability, and thermal stability of treated wood were also investigated. After homogenization, a milk-white oil-in-water (O/W) paraffin Pickering emulsion stabilized by the nano-SiO2 (diameter of ~76 nm) was formed and demonstrated excellent storage stability. Paraffin Pickering emulsion could penetrate into the wood structure. The emulsion-treated wood was endowed with a moderate anti-swelling efficiency (ASE), high water resistance, and low wettability. Moreover, the addition of nano-SiO2 could improve the thermal stability of the treated wood.


2018 ◽  
Vol 775 ◽  
pp. 57-62 ◽  
Author(s):  
Patcharaporn Chuayplod ◽  
Duangdao Aht-Ong

Surface treated parawood microcrystalline cellulose (PW-MCC) performed under mechanochemical reaction using planetary ball milling at ambient temperature was used as a reinforcing material in polypropylene composites. Initially, PW-MCC was prepared by acid hydrolysis of parawood sawdust pulp. After that, PW-MCC was treated with vinyltrimethoxysilane at milling speed 400 rpm for 60 min. The surface composition from XPS indicated the existence of silicon atom on silane-treated PW-MCC. The thermal stability of PW-MCC was also improved and SEM micrograph revealed rough surface after modification reaction. The untreated PW-MCC and treated PW-MCC were applied to prepare polypropylene composites at 5-30 wt% loading content without a compatibilizer. The results demonstrated that silane-treated PW-MCC/PP composites enhanced tensile strength, thermal stability and water resistance of the composites.


2010 ◽  
Vol 66 (6) ◽  
pp. 797-802 ◽  
Author(s):  
Hojatollah Kiani ◽  
Alireza Ashori ◽  
S. Ahmad Mozaffari

Materials ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 2641 ◽  
Author(s):  
Tang ◽  
Wang ◽  
Wang ◽  
Cheng ◽  
Guo

The demand for eco-friendly renewable natural fibers has grown in recent years. In this study, a series of polypropylene-based composites reinforced with single bamboo fibers (SBFs), prepared by non-woven paving and a hot-pressing process, were investigated. The influence of the content of SBF on impact strength, flexural strength, and water resistance was analyzed. The properties of the composites were greatly affected by the SBF content. Impact strength increased as SBF content increased. The modulus of rupture and modulus of elasticity show an optimum value, with SBF contents of 40% and 50%, respectively. The surface morphology of the fractured surfaces of the composites was characterized by scanning electron microscopy. The composites showed poor interfacial compatibility. The water resistance indicates that the composites with higher SBF contents have higher values of water absorption and thickness swelling, due to the hydrophilicity of the bamboo fibers. The thermal properties of the composites were characterized by thermal gravimetric analysis and by differential scanning calorimetry. The thermal stability of the composites was gradually reduced, due to the poor thermal stability of SBFs. In the composites, the maximum decomposition temperature corresponding to SBF shows an increasing trend. However, the maximum decomposition temperature of polypropylene was not influenced by SBF content. The melting point of the polypropylene in the composites was lower relative to pure polypropylene, although it was not affected by increasing SBF content.


2021 ◽  
Author(s):  
Mingxiang Jiang ◽  
Qingqing Wu ◽  
Jiaorong Yan ◽  
Jun Pan ◽  
Qiguang Dai ◽  
...  

Abstract Catalytic combustion of propane as typical light alkanes was important for the purification of industrial VOCs and automobile hydrocarbon emissions. Si-doped Al2O3 nanosheet was synthesized by a hydrothermal method, and effects of Si content on the morphology and thermal stability of Al2O3 were investigated. The doping of SiO2 could tune the thickness of Al2O3 nanosheets and significantly improve its thermal stability, the θ phase was still maintained and the specific surface area was as high as 56.3 m2∙g-1 after calcination at 1200 ℃. And then the Si-doped Al2O3 nanosheets were used as support of Pd catalysts (Pd/Si-Al2O3 nanosheets) for catalytic combustion of propane, especially Pd/3.6Si-Al2O3 nanosheets, which presented high activity, stability and resistance to sintering and H2O due to the promotion of Si on the thermal stability of Al2O3 and the stabilization (dispersion, isolation and strong interaction) of PdOx species.


BioResources ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. 7444-7460
Author(s):  
Pengwei Zhao ◽  
Hong Yang ◽  
Guoqi Xu ◽  
Congxun Huang ◽  
Yan Zhong

A nano-CuO/silica sol wood preservative was obtained by dispersing CuO nanoparticles in propylene glycol and silica sol. Scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction analysis, thermogravimetric analysis, and compressive tests were conducted to investigate the effects of different post-treatments, i.e., steaming at 100 °C and freezing at -30 °C, on the variations in microstructure, mechanical, physical, and thermal stability properties of the preservative-impregnated wood. The results revealed that the mechanical properties, water resistance, and thermal stability of the impregnated specimens were greatly ameliorated. The steaming treatment resulted in a more uniform and dense distribution of the preservative in the blocks. The steaming treatment performed better in terms of enhancing the compressive strength of the specimens, while the freezing treatment was more effective in improving the thermal stability of the specimens. Both the steaming and freezing treatments can considerably improve the water resistance of the specimens. The different post-treatments retain the basic properties of the wood; however, they differ in the improved wood properties and provide a basis for their selection in the industrial production of nano-preservatives.


Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization


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