The addition of graphene oxide(GO)to cement paste significantly increases its toughness,however its fluidity is adversely affected.GO was first reacted with vinyltrimethoxysilane to produce a silane-modified graphene ...The addition of graphene oxide(GO)to cement paste significantly increases its toughness,however its fluidity is adversely affected.GO was first reacted with vinyltrimethoxysilane to produce a silane-modified graphene oxide(S-GO),which was then copolymerized with acrylic acid and a water reducing agent,isobutaenol polyoxyethylene ether(molecular mass 2400),to obtain a silane and copolymer-modified GO(P-S-GO)which acted as a water-reducing agent of the cement paste.A copolymer without GO was prepared under the same conditions for comparison.The structure,elemental composition and dispersibility of GO,S-GO and P-S-GO in a simulated cement environment(saturated lime water)were investigated by FTIR,XRD and a sedimentation test.The fluidity and rheology of the cement pastes with added GO,copolymer or P-S-GO were investigated.Results showed that vinyltrimethoxysilane reacted with the-OH group on the GO sheets to form an ether bond and the copolymer was grafted onto a vinyl group of S-GO by an addition reaction to produce the P-S-GO.The P-S-GO has a better dispersibility in saturated lime water with a negligible amount of aggregation compared to GO and a significant agglomeration occurs for GO.The addition of the P-S-GO to the cement pastes improves the fluidity and rheological properties compared with GO,offsetting the negative impact of GO and increasing the toughness of the resulting cements.展开更多
In this work, low-temperature vulcanized, transparent silane modified epoxy resins for LED filament bulb package were prepared. Firstly, transparent silane modified epoxy resins were produced through a controllable so...In this work, low-temperature vulcanized, transparent silane modified epoxy resins for LED filament bulb package were prepared. Firstly, transparent silane modified epoxy resins were produced through a controllable sol-gel method using γ-（2,3-epoxypropoxy）propytrimethoxysilane and dimethyldiethoxylsilane. The features of the reaction were investigated and the products were characterized in detail. Subsequently, various curing agents were explored to prepare transparent silane modified epoxy resins. The silane modified epoxy resins cured by PEA-230 at a fairly low temperature（40 °C/2 h then 60 °C/1 h） exhibited excellent thermal stability with a thermal degradation temperature as high as 316.5 °C and adjustable hardness between 40-60 shore A. The application tests showed the materials obtained were good candidates for LED filament bulb package.展开更多
Bilayer-silane-coated Fe304 nanoparticles with inner layer of tetraethoxy silane （TEOS） and outer layer of vinyltriethoxysilane （VTEO） were generated to enhance their acid resistance. These nanoparticles were copo...Bilayer-silane-coated Fe304 nanoparticles with inner layer of tetraethoxy silane （TEOS） and outer layer of vinyltriethoxysilane （VTEO） were generated to enhance their acid resistance. These nanoparticles were copolymerized with vinylbenzyl chloride （VBC） using suspension polymerization, and then post-crosslinked. The resulting hypercrosslinked magnetic resin M150 presented specific bimodal property with large specific surface area of 1109 m2/g. It exhibited more excellent adsorption capacity of p- nitrophenol compared to another two magnetic adsorbents Q150 and MIEX~. Moreover, the acid stable property of the magnetite in MI50 extended its application at low pH value.展开更多
文摘The addition of graphene oxide(GO)to cement paste significantly increases its toughness,however its fluidity is adversely affected.GO was first reacted with vinyltrimethoxysilane to produce a silane-modified graphene oxide(S-GO),which was then copolymerized with acrylic acid and a water reducing agent,isobutaenol polyoxyethylene ether(molecular mass 2400),to obtain a silane and copolymer-modified GO(P-S-GO)which acted as a water-reducing agent of the cement paste.A copolymer without GO was prepared under the same conditions for comparison.The structure,elemental composition and dispersibility of GO,S-GO and P-S-GO in a simulated cement environment(saturated lime water)were investigated by FTIR,XRD and a sedimentation test.The fluidity and rheology of the cement pastes with added GO,copolymer or P-S-GO were investigated.Results showed that vinyltrimethoxysilane reacted with the-OH group on the GO sheets to form an ether bond and the copolymer was grafted onto a vinyl group of S-GO by an addition reaction to produce the P-S-GO.The P-S-GO has a better dispersibility in saturated lime water with a negligible amount of aggregation compared to GO and a significant agglomeration occurs for GO.The addition of the P-S-GO to the cement pastes improves the fluidity and rheological properties compared with GO,offsetting the negative impact of GO and increasing the toughness of the resulting cements.
基金financial support from the Zhejiang Provincial Natural Science Foundation of China (No.Y14E030008)the Commonweal Technology Application Research Project of Zhejiang Province (No.2013C31079)
文摘In this work, low-temperature vulcanized, transparent silane modified epoxy resins for LED filament bulb package were prepared. Firstly, transparent silane modified epoxy resins were produced through a controllable sol-gel method using γ-（2,3-epoxypropoxy）propytrimethoxysilane and dimethyldiethoxylsilane. The features of the reaction were investigated and the products were characterized in detail. Subsequently, various curing agents were explored to prepare transparent silane modified epoxy resins. The silane modified epoxy resins cured by PEA-230 at a fairly low temperature（40 °C/2 h then 60 °C/1 h） exhibited excellent thermal stability with a thermal degradation temperature as high as 316.5 °C and adjustable hardness between 40-60 shore A. The application tests showed the materials obtained were good candidates for LED filament bulb package.
基金support provided by Program for Changjiang Scholars and Innovative Research Team in University,NSFC(Nos.50825802 and 51178215)Jiangsu Nature Science Fund(Nos. BK2010006 and BK2011032)P.R.China
文摘Bilayer-silane-coated Fe304 nanoparticles with inner layer of tetraethoxy silane （TEOS） and outer layer of vinyltriethoxysilane （VTEO） were generated to enhance their acid resistance. These nanoparticles were copolymerized with vinylbenzyl chloride （VBC） using suspension polymerization, and then post-crosslinked. The resulting hypercrosslinked magnetic resin M150 presented specific bimodal property with large specific surface area of 1109 m2/g. It exhibited more excellent adsorption capacity of p- nitrophenol compared to another two magnetic adsorbents Q150 and MIEX~. Moreover, the acid stable property of the magnetite in MI50 extended its application at low pH value.
