This study was to develop the flame retardant (FR) protective clothing which had multifunction such anti-bacterial, UV cut, FR function with water repellent and water vapor permeable laminating textiles for industrial...This study was to develop the flame retardant (FR) protective clothing which had multifunction such anti-bacterial, UV cut, FR function with water repellent and water vapor permeable laminating textiles for industrial workers. First of all, the FR yarn and FR textiles were developed for this purpose. Second, the comparison analysis between the halogen laminating textiles and halogen-free laminating textiles were tested to figure out the eco-friendly laminating method. Third, the flame retardant ability was compared the halogen laminated textiles to halogen-free laminated textiles. LOI, UV protection ratio, antibiosis after 50 laundry test, water proof pressure, and moisture permeability of developed textiles were tested. GC-HR-TOF-MS was used for analysis of laminating film (halogen and halogen-free). 4.1 wt% TiO2 yarn showed antibacterial function (Pneumococcus & Staphylococcus aureus: 99.9%), UV Protection (UVA: 90.8, UVB: 92.1), and LOI (33.6). The chosen optimal compounding ratio for PU compound of HRF and HFFR were as followed: PU resin 58.3%, DMF (Dimethyl formamide, δ = 12.2) 8.3%, MEK (Methylethylketone) 8.3% and FR (flame retardants) 25.0%. Binder for laminating should not be included over 10% of FRs because of adhesion between textiles and FR laminating film. There were detected phosphorus compounds in the textiles treated by halogenated type flame retardants and halogenated-free type flame retardants. There were not any detected harmful compounds from all textile samples.展开更多
The atom-economical cycloaddition of CO_(2) with epoxides to synthesize cyclic carbonates is a promising route for valuable utilization of CO_(2).Halogenide such as alkali metal halides and quaternary ammonium salt ha...The atom-economical cycloaddition of CO_(2) with epoxides to synthesize cyclic carbonates is a promising route for valuable utilization of CO_(2).Halogenide such as alkali metal halides and quaternary ammonium salt have been developed as the efficient catalysts.However,the spilled halogen causes equipment corrosion and affects the product purity.To address these concerns,the halogen-free cycloaddition of CO_(2) with epoxides has always been desired.In this review,we systematically discussed the halogen-free catalysis for cycloaddition of CO_(2) with epoxides from the mechanistic insights,aiming to promote the development of efficient halogen-free catalysts.Two types of catalysts,i.e.,alternatives of halogen nucleophiles for epoxide activation,and bifunctional catalysts with Lewis acid-base sites for synergistic activation of CO_(2) and epoxides are summarized and emphasized.Specially,metal oxides as the potential halogen-free catalysts are highlighted due to their flexible acid-base sites for synergistic activation of CO_(2) and epoxides,facile preparation,and low cost.展开更多
To study the effects of different proportions of aluminum hydroxide and expandable graphite (EG) composites on flame retardation, sealing, mechanical, electrical and other properties of RTV- 1, aluminum hydroxide/ex...To study the effects of different proportions of aluminum hydroxide and expandable graphite (EG) composites on flame retardation, sealing, mechanical, electrical and other properties of RTV- 1, aluminum hydroxide/expandable graphite (ATH/EG) and silicone rubber composites were prepared by the compression molding method. The experimental results show that heat resistance improves with the increase of proportion of EG. Although the resistance coefficient changes, the composite materials still keep good electrical insulating property. Moreover, oxygen index and expansion index rise first then fall. When ATH/EG is 1:1, the oxygen index reaches the highest; the mechanical property of the silicone rubber is not affected under various environments such as acid, alkali, oily, artificial sea water environments, etc.展开更多
A series of new halogen-free dicationic ionic liquids(ILs)with different alkyl chain lengths were prepared,and the relationship between the alkyl chain length,physicochemical and tribological properties of ILs,and the...A series of new halogen-free dicationic ionic liquids(ILs)with different alkyl chain lengths were prepared,and the relationship between the alkyl chain length,physicochemical and tribological properties of ILs,and their role as neat lubricant for steel–steel friction pairs,was investigated.Evaluation of stability during hydrolysis and copper strip corrosion test results show that synthetic ILs are stable and not corrosive to metal contacts,due to the halogen-free anions.The friction and wear test results indicate that ILs with long alkyl chains have excellent friction-reducing and anti-wear properties,especially at high temperatures.Based on the surface three-dimensional(3D)profiles,electrical contact resistance,scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),and the X-ray photoelectron spectrometry(XPS)analysis of the worn surfaces of steel discs,we can conclude that the efficiency of ILs is due to the formation of high quality tribofilms that consist of both tribochemical reaction and ordered absorption films.展开更多
Poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt(4,4′-(N-(4-butylphenyl))](TFB),one of the most popular and widely used hole-transport layer(HTL)materials,has been successfully applied in high performance spin-coated quantum...Poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt(4,4′-(N-(4-butylphenyl))](TFB),one of the most popular and widely used hole-transport layer(HTL)materials,has been successfully applied in high performance spin-coated quantum dots-based light-emitting diodes(QLEDs)due to its suitable energy level and high mobility.However,there are still many challenging issues in inkjet-printed QLED devices when using TFB as HTL.TFB normally suffers from the interlayer mixing and erosion,and low surface energy against the good film formation.Here,a novel environment-friendly binary solvent system was established for formulating quantum dot(QD)inks,which is based on mixing halogen-free alkane solvents of decalin and n-tridecane.The optimum volume ratio for the mixture of decalin and n-tridecane was found to be 7:3,at which a stable ink jetting flow and coffee-ring free QD films could be formed.To research the influence of substrate surface on the formation of inkjet-printed QD films,TFB was annealed at different temperatures,and the optimum annealing temperature was found to enable high quality inkjet-printed QD film.Inkjet-printed red QLED was ultimately manufactured.A maximum 18.3%of external quantum efficiency(EQE)was achieved,reaching 93%of the spin-coated QLED,which is the best reported high efficiency inkjet-printed red QLEDs to date.In addition,the inkjet-printed QLED achieved similar T75 operational lifetime(27 h)as compared to the spin-coated reference QLED(28 h)at 2,000 cd·m−2.This work demonstrated that the novel orthogonal halogen-free alkane co-solvents can improve the interfacial contact and facilitate high-performance inkjet printing QLEDs with high EQE and stability.展开更多
The chemical transformation of CO2 and epoxides into cyclic carbonates has been receiving much attention and is one of the successful examples for CO2 utilization as carbon resource.Many catalysts containing halide an...The chemical transformation of CO2 and epoxides into cyclic carbonates has been receiving much attention and is one of the successful examples for CO2 utilization as carbon resource.Many catalysts containing halide anions have been explored and exhibit excellent catalytic activity.However,halogen salt is generally toxic and corrosive to reactors.From a green chemistry perspective,it is more attractive to develop a halogen-free catalyst with excellent performance.Herein,a review of recent research progress of halogen-free catalysts in the cycloaddition of CO2 and epoxide is presented.According to previous experimental and theoretical works,two possible strategies for achieving the halogen-free process were summarized.The relationship between catalytic activity and catalyst structure,the mechanism of CO2 activation should be both studied deeply combined with experimental results and DFT calculation,which can guide the design of new catalysts and realize halogen-free process under mild reaction conditions.展开更多
Polymer solar cells(PSCs)consisting of a polymer donor and a small molecular acceptor is a promising photovoltaic technology,whose device performance is determined by both polymer donor and small molecular acceptor.Ha...Polymer solar cells(PSCs)consisting of a polymer donor and a small molecular acceptor is a promising photovoltaic technology,whose device performance is determined by both polymer donor and small molecular acceptor.Halogen atoms such as fluorine or chlorine atoms were usually introduced onto the polymer donors to downshift the highest occupied molecular orbital(HOMO)energy levels and improve the open-circuit voltage(VOC)of the PSCs.However,the introduction of the halogen atoms especially fluorine atoms greatly complicates the polymer synthesis.Herein,we report the use of a structural simple and easily synthesized building block,3,4-dicyanothiophene(DCT),to construct a set of halogen-free polymer donors PBCNTx(x=25,50,75)via ternary random copolymerization.The introduction of DCT units not only simplified the synthesis,but also downshifted the HOMO energy levels of the polymers and improved the V_(OC) of PSCs effectively.Encouragingly,the PBCNT75 afforded a power conversion efficiency up to 15.7%with a V_(OC) of 0.83 V,which are among the top values for halogen-free polymer donors.This work shows that the introduction of DCT units is a simple yet effective strategy to construct halogen-free and low-cost polymer donors for high-performance PSCs.展开更多
For the first time,we employed the halogen-free deep eutectic solvent(DES)into the Knoevenagel condensation between aromatic aldehydes and active methylene compounds at room temperature.The DESs[3Im:PTSA]and[4Im:PTSA]...For the first time,we employed the halogen-free deep eutectic solvent(DES)into the Knoevenagel condensation between aromatic aldehydes and active methylene compounds at room temperature.The DESs[3Im:PTSA]and[4Im:PTSA]were prepared by imidazole(Im)and p-tol-uenesulfonic acid(PTSA),which were experimentally screened from a series of organic acids with imidazole.a,b-Unsaturated carbonyl compounds were obtained in good to excellent yields under solvent-free conditions with fast reaction rate.These two DESs can be reused for multiple times with no loss of catalytic activity.展开更多
Bisphenol A bis(diphenyl phosphate) oligomer(BDP) is prepared successfully from the reactants consisting of phosphorus oxyehloride (POCl3), bisphenol A and phenol with a Friedel-Crafts catalyst. The resultant pr...Bisphenol A bis(diphenyl phosphate) oligomer(BDP) is prepared successfully from the reactants consisting of phosphorus oxyehloride (POCl3), bisphenol A and phenol with a Friedel-Crafts catalyst. The resultant products were examined with thermtygravimetrie analysis (TGA) and high performance liquid chro- matography(HPLC). Thermogravimetry data shows that BDP decomposes at 375℃ when 5 % weight lost. Experiments results show that catalyst is preferably AICI3 and the amount of it is preferably 1% relative to bisphenol A by mole. POCl3/bisphenol A mole ratio is preferably about 5:1 to 6:1. Experiments unclosed that a seal apparatus is very important to the properties of product.展开更多
Driven by global environmental concerns,many efforts have been made to develop halogen-free flame retardants for rigid polyurethane foam(RPUF).These environmentally benign flame retardants are mainly divided into(i)re...Driven by global environmental concerns,many efforts have been made to develop halogen-free flame retardants for rigid polyurethane foam(RPUF).These environmentally benign flame retardants are mainly divided into(i)reactive,(ii)additive,and(iii)coating types.The last decade has witnessed great progress of these three strategies,which enhance the fire safety of RPUF and maintain even improve the thermal insulation properties.This comprehensive review focuses on the up-to-date design of the reactive,additive,and coating flame retardants,and their effects on flame retardancy and thermal conductivity of RPUF.Moreover,the practical applications of the as-prepared flame-retardant RPUFs are highlighted.Finally,key challenges associated with these three kinds of flame retardants are discussed and future research opportunities are also proposed.展开更多
文摘This study was to develop the flame retardant (FR) protective clothing which had multifunction such anti-bacterial, UV cut, FR function with water repellent and water vapor permeable laminating textiles for industrial workers. First of all, the FR yarn and FR textiles were developed for this purpose. Second, the comparison analysis between the halogen laminating textiles and halogen-free laminating textiles were tested to figure out the eco-friendly laminating method. Third, the flame retardant ability was compared the halogen laminated textiles to halogen-free laminated textiles. LOI, UV protection ratio, antibiosis after 50 laundry test, water proof pressure, and moisture permeability of developed textiles were tested. GC-HR-TOF-MS was used for analysis of laminating film (halogen and halogen-free). 4.1 wt% TiO2 yarn showed antibacterial function (Pneumococcus & Staphylococcus aureus: 99.9%), UV Protection (UVA: 90.8, UVB: 92.1), and LOI (33.6). The chosen optimal compounding ratio for PU compound of HRF and HFFR were as followed: PU resin 58.3%, DMF (Dimethyl formamide, δ = 12.2) 8.3%, MEK (Methylethylketone) 8.3% and FR (flame retardants) 25.0%. Binder for laminating should not be included over 10% of FRs because of adhesion between textiles and FR laminating film. There were detected phosphorus compounds in the textiles treated by halogenated type flame retardants and halogenated-free type flame retardants. There were not any detected harmful compounds from all textile samples.
基金Financial support from the National Key R&D Program of China(Grant No.2022YFB4101900)National Natural Science Foundation of China(Grant Nos.22278305 and U21B2096).
文摘The atom-economical cycloaddition of CO_(2) with epoxides to synthesize cyclic carbonates is a promising route for valuable utilization of CO_(2).Halogenide such as alkali metal halides and quaternary ammonium salt have been developed as the efficient catalysts.However,the spilled halogen causes equipment corrosion and affects the product purity.To address these concerns,the halogen-free cycloaddition of CO_(2) with epoxides has always been desired.In this review,we systematically discussed the halogen-free catalysis for cycloaddition of CO_(2) with epoxides from the mechanistic insights,aiming to promote the development of efficient halogen-free catalysts.Two types of catalysts,i.e.,alternatives of halogen nucleophiles for epoxide activation,and bifunctional catalysts with Lewis acid-base sites for synergistic activation of CO_(2) and epoxides are summarized and emphasized.Specially,metal oxides as the potential halogen-free catalysts are highlighted due to their flexible acid-base sites for synergistic activation of CO_(2) and epoxides,facile preparation,and low cost.
文摘To study the effects of different proportions of aluminum hydroxide and expandable graphite (EG) composites on flame retardation, sealing, mechanical, electrical and other properties of RTV- 1, aluminum hydroxide/expandable graphite (ATH/EG) and silicone rubber composites were prepared by the compression molding method. The experimental results show that heat resistance improves with the increase of proportion of EG. Although the resistance coefficient changes, the composite materials still keep good electrical insulating property. Moreover, oxygen index and expansion index rise first then fall. When ATH/EG is 1:1, the oxygen index reaches the highest; the mechanical property of the silicone rubber is not affected under various environments such as acid, alkali, oily, artificial sea water environments, etc.
基金The authors acknowledge financial support from the National Key Research and Development Program of China(2018YFB0703802)the National Natural Science Foundation of China(Grant Nos.51705504,21972153,and 51675512)+3 种基金the China Postdoctoral Science Foundation Funded Project(2019M653798)the Youth Innovation Promotion Association of CAS(2018454)the pre-research project in the manned space field(040101)the Gansu Province Science and Technology Plan(18ZD2WA011).
文摘A series of new halogen-free dicationic ionic liquids(ILs)with different alkyl chain lengths were prepared,and the relationship between the alkyl chain length,physicochemical and tribological properties of ILs,and their role as neat lubricant for steel–steel friction pairs,was investigated.Evaluation of stability during hydrolysis and copper strip corrosion test results show that synthetic ILs are stable and not corrosive to metal contacts,due to the halogen-free anions.The friction and wear test results indicate that ILs with long alkyl chains have excellent friction-reducing and anti-wear properties,especially at high temperatures.Based on the surface three-dimensional(3D)profiles,electrical contact resistance,scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),and the X-ray photoelectron spectrometry(XPS)analysis of the worn surfaces of steel discs,we can conclude that the efficiency of ILs is due to the formation of high quality tribofilms that consist of both tribochemical reaction and ordered absorption films.
基金This work was supported by the National Key Research and Development Program of China(No.2016YFB0401600)the National Natural Science Foundation of China(No.U1605244)China Postdoctoral Science Foundation(No.2020M681726).
文摘Poly[(9,9-dioctylfluorenyl-2,7-diyl)-alt(4,4′-(N-(4-butylphenyl))](TFB),one of the most popular and widely used hole-transport layer(HTL)materials,has been successfully applied in high performance spin-coated quantum dots-based light-emitting diodes(QLEDs)due to its suitable energy level and high mobility.However,there are still many challenging issues in inkjet-printed QLED devices when using TFB as HTL.TFB normally suffers from the interlayer mixing and erosion,and low surface energy against the good film formation.Here,a novel environment-friendly binary solvent system was established for formulating quantum dot(QD)inks,which is based on mixing halogen-free alkane solvents of decalin and n-tridecane.The optimum volume ratio for the mixture of decalin and n-tridecane was found to be 7:3,at which a stable ink jetting flow and coffee-ring free QD films could be formed.To research the influence of substrate surface on the formation of inkjet-printed QD films,TFB was annealed at different temperatures,and the optimum annealing temperature was found to enable high quality inkjet-printed QD film.Inkjet-printed red QLED was ultimately manufactured.A maximum 18.3%of external quantum efficiency(EQE)was achieved,reaching 93%of the spin-coated QLED,which is the best reported high efficiency inkjet-printed red QLEDs to date.In addition,the inkjet-printed QLED achieved similar T75 operational lifetime(27 h)as compared to the spin-coated reference QLED(28 h)at 2,000 cd·m−2.This work demonstrated that the novel orthogonal halogen-free alkane co-solvents can improve the interfacial contact and facilitate high-performance inkjet printing QLEDs with high EQE and stability.
基金supported by the National Key Research and Development Program of China(2018YFB0605801)National Natural Science Foundation of China(21871277)Chinese Academy of Sciences(QYZDYSSW-SLH013).
文摘The chemical transformation of CO2 and epoxides into cyclic carbonates has been receiving much attention and is one of the successful examples for CO2 utilization as carbon resource.Many catalysts containing halide anions have been explored and exhibit excellent catalytic activity.However,halogen salt is generally toxic and corrosive to reactors.From a green chemistry perspective,it is more attractive to develop a halogen-free catalyst with excellent performance.Herein,a review of recent research progress of halogen-free catalysts in the cycloaddition of CO2 and epoxide is presented.According to previous experimental and theoretical works,two possible strategies for achieving the halogen-free process were summarized.The relationship between catalytic activity and catalyst structure,the mechanism of CO2 activation should be both studied deeply combined with experimental results and DFT calculation,which can guide the design of new catalysts and realize halogen-free process under mild reaction conditions.
基金The work was financially supported by the Ministry of Science and Technology of China(Nos.2017YFA0206600 and 2019YFA0705900)the National Natural Science Foundation of China(Nos.21875072,U20A6002 and 51973169)+2 种基金Guangdong Innovative and Entrepreneurial Research Team Program(No.2019ZT08L075)This study also received financial support from Science and Technology Foundation of Guangdong Province(No.2021A0101180005)Special Projects in Key Areas for the University of Guangdong Province(No.2021ZDZX1009).
文摘Polymer solar cells(PSCs)consisting of a polymer donor and a small molecular acceptor is a promising photovoltaic technology,whose device performance is determined by both polymer donor and small molecular acceptor.Halogen atoms such as fluorine or chlorine atoms were usually introduced onto the polymer donors to downshift the highest occupied molecular orbital(HOMO)energy levels and improve the open-circuit voltage(VOC)of the PSCs.However,the introduction of the halogen atoms especially fluorine atoms greatly complicates the polymer synthesis.Herein,we report the use of a structural simple and easily synthesized building block,3,4-dicyanothiophene(DCT),to construct a set of halogen-free polymer donors PBCNTx(x=25,50,75)via ternary random copolymerization.The introduction of DCT units not only simplified the synthesis,but also downshifted the HOMO energy levels of the polymers and improved the V_(OC) of PSCs effectively.Encouragingly,the PBCNT75 afforded a power conversion efficiency up to 15.7%with a V_(OC) of 0.83 V,which are among the top values for halogen-free polymer donors.This work shows that the introduction of DCT units is a simple yet effective strategy to construct halogen-free and low-cost polymer donors for high-performance PSCs.
基金The financial support from National Natural Science Foundation of China(21576081,21776074 and 2181101120)is greatly acknowledged.
文摘For the first time,we employed the halogen-free deep eutectic solvent(DES)into the Knoevenagel condensation between aromatic aldehydes and active methylene compounds at room temperature.The DESs[3Im:PTSA]and[4Im:PTSA]were prepared by imidazole(Im)and p-tol-uenesulfonic acid(PTSA),which were experimentally screened from a series of organic acids with imidazole.a,b-Unsaturated carbonyl compounds were obtained in good to excellent yields under solvent-free conditions with fast reaction rate.These two DESs can be reused for multiple times with no loss of catalytic activity.
文摘Bisphenol A bis(diphenyl phosphate) oligomer(BDP) is prepared successfully from the reactants consisting of phosphorus oxyehloride (POCl3), bisphenol A and phenol with a Friedel-Crafts catalyst. The resultant products were examined with thermtygravimetrie analysis (TGA) and high performance liquid chro- matography(HPLC). Thermogravimetry data shows that BDP decomposes at 375℃ when 5 % weight lost. Experiments results show that catalyst is preferably AICI3 and the amount of it is preferably 1% relative to bisphenol A by mole. POCl3/bisphenol A mole ratio is preferably about 5:1 to 6:1. Experiments unclosed that a seal apparatus is very important to the properties of product.
基金financially supported by the Australian Research Council(Nos.DP190102992,FT190100188)the National Natural Science Foundation of China(No.51873196)the Key Research and Development Projects of Zhejiang Province(No.2019C01098)。
文摘Driven by global environmental concerns,many efforts have been made to develop halogen-free flame retardants for rigid polyurethane foam(RPUF).These environmentally benign flame retardants are mainly divided into(i)reactive,(ii)additive,and(iii)coating types.The last decade has witnessed great progress of these three strategies,which enhance the fire safety of RPUF and maintain even improve the thermal insulation properties.This comprehensive review focuses on the up-to-date design of the reactive,additive,and coating flame retardants,and their effects on flame retardancy and thermal conductivity of RPUF.Moreover,the practical applications of the as-prepared flame-retardant RPUFs are highlighted.Finally,key challenges associated with these three kinds of flame retardants are discussed and future research opportunities are also proposed.
基金financial support from the National Natural Science Foundation of China (91333204, 21325419 and 51673201)the Chinese Academy of Sciences (XDB12030200, KJZD-EW-J01)+3 种基金the National Basic Research Program 973 (2014CB643501)the CAS-Croucher Funding Scheme for Joint Laboratories (CAS14601)supported by the US Office of Naval Resea (ONR) grant N00141512322supported by a Research Opportunity Initiative grant by the UNC General Administatrtion