Chemical modification(CM)and deposition-precipitation(DP)methods were used for the dispersion of active Au nanoparticles on mesoporous silica materials in this work.XRD,TEM,N2 adsorption isotherms and UV-Vis absorptio...Chemical modification(CM)and deposition-precipitation(DP)methods were used for the dispersion of active Au nanoparticles on mesoporous silica materials in this work.XRD,TEM,N2 adsorption isotherms and UV-Vis absorption spectra were used to characterize in detail Au-SBA-15 materials prepared by the two methods. The analysis results showed that high loading(1.7%,by mass)and uniform Au nanoparticles(approximately 3 nm) were dispersed in the channels of mesoporous SBA-15 by the CM method.While for the DP method,most of Au nanoparticles with the size of 10—15nm were aggregated outside of the channels of SBA-15 and the actual loading of Au was only 0.38%(by mass).展开更多
Stability, specificity, and pharmacokinetic properties are some of the challenges facing RNAi therapeutics. In this review, the progresses in chemically modified siRNAs and siRNA conjugates are summarized. The proper ...Stability, specificity, and pharmacokinetic properties are some of the challenges facing RNAi therapeutics. In this review, the progresses in chemically modified siRNAs and siRNA conjugates are summarized. The proper modification of siRNA with nucleoside analogues, construction of siRNA conjugates, and reliable prediction of the property based on those strategies for a given siRNA sequence would certainly be an essential part of the solution to these challenges.展开更多
Graphene has attracted the interest of chemists, physicists, and materials scientists due to its extraordinary structural, mechanical, and electronic properties. While pristine graphene is desirable for applications t...Graphene has attracted the interest of chemists, physicists, and materials scientists due to its extraordinary structural, mechanical, and electronic properties. While pristine graphene is desirable for applications that require a high electrical conductivity, many other applications require modified or functionalized forms of graphene, such as graphene oxide, reduced graphene, or other functionalized forms. Structurally modifying graphene through chemical functionalization reveals the numerous possibilities for tuning its structure; several chemical and physical functionalization methods have been explored to improve the stabilization and modification of graphene. In this review, we report recent progress towards the chemical modification of graphene, including both covalent and noncovalent methods, for use in various applications.展开更多
As a small catalytic DNA molecule, 10-23 DNAzyme has cleavage ability against complementary RNA. Previous studies of chemical modification have shown that its catalytic core can be further optimized in order to obtain...As a small catalytic DNA molecule, 10-23 DNAzyme has cleavage ability against complementary RNA. Previous studies of chemical modification have shown that its catalytic core can be further optimized in order to obtain more powerful catalytic ability. The analogues of 2＇-deoxyadenosine （5） and 2＇-deoxyguanosine （6） could improve the cleavage ability of the DNAzyme when positioned at positions A9, （32 and G14 in the catalytic core, respectively. Moreover, their combinatorial incorporations were studied, the results implicated that the effect was position-dependent, and positive additive results could be achieved at some positions. The highly conserved G1, G2 and G14 could be optimized by single or combinatorial modification with 2＇-deoxyguanosine analogues. Chemical modifications on the functional groups of the core residues would be a feasible approach for the optimization of 10-23 DNAzyme.展开更多
Two-dimensional(2D)metal oxides and chalcogenides(MOs&MCs)have been regarded as a new class of promising electro-and photocatalysts for many important chemical reactions such as hydrogen evolution reaction,CO_(2) ...Two-dimensional(2D)metal oxides and chalcogenides(MOs&MCs)have been regarded as a new class of promising electro-and photocatalysts for many important chemical reactions such as hydrogen evolution reaction,CO_(2) reduction reaction and N2 reduction reaction in virtue of their outstanding physicochemical properties.However,pristine 2D MOs&MCs generally show the relatively poor catalytic performances due to the low electrical conductivity,few active sites and fast charge recombination.Therefore,considerable efforts have been devoted to engineering 2D MOs&MCs by rational structural design and chemical modification to further improve the catalytic activities.Herein,we comprehensively review the recent advances for engineering technologies of 2D MOs&MCs,which are mainly focused on the intercalation,doping,defects creation,facet design and compositing with functional materials.Meanwhile,the relationship between morphological,physicochemical,electronic,and optical properties of 2D MOs&MCs and their electro-and photocatalytic performances is also systematically discussed.Finally,we further give the prospect and challenge of the field and possible future research directions,aiming to inspire more research for achieving high-performance 2D MOs&MCs catalysts in energy storage and conversion fields.展开更多
Device stability becomes one of the most crucial issues for the commercialization of organic solar cells(OSCs) after high power conversion efficiencies have been achieved. Besides the intrinsic stability of photoactiv...Device stability becomes one of the most crucial issues for the commercialization of organic solar cells(OSCs) after high power conversion efficiencies have been achieved. Besides the intrinsic stability of photoactive materials, the chemical/catalytic reaction between interfacial materials and photoactive materials is another critical factor that determines the stability of OSC devices. Herein, we design and synthesize a reaction-inert rylene diimide-embedded hyperbranched polymer named as PDIEIE, which effectively reduces the work function of indium tin oxide electrode from 4.62 to 3.65 eV. Meanwhile, PDIEIE shows negligible chemical reaction with high-performance photoactive materials and no catalytic effect under strong ultraviolet illumination, resulting in much better photo-stability of OSCs with PDIEIE cathode interlayer(CIL), relative to the traditional CILs, including most-widely used metal oxides and polyethyleneimine derivatives.展开更多
基金Supported by the National Natural Science Foundation of China （No.20490204）, Shanghai Municipal Science and Technology Commission of China （No.05DJ 14002） and Shanghai Municipal Education Commission of China.
文摘Chemical modification(CM)and deposition-precipitation(DP)methods were used for the dispersion of active Au nanoparticles on mesoporous silica materials in this work.XRD,TEM,N2 adsorption isotherms and UV-Vis absorption spectra were used to characterize in detail Au-SBA-15 materials prepared by the two methods. The analysis results showed that high loading(1.7%,by mass)and uniform Au nanoparticles(approximately 3 nm) were dispersed in the channels of mesoporous SBA-15 by the CM method.While for the DP method,most of Au nanoparticles with the size of 10—15nm were aggregated outside of the channels of SBA-15 and the actual loading of Au was only 0.38%(by mass).
基金National NaturalScience Foundation of China (Grant No.2093200 1,20832008)National Basic Research Program of China(Grant No.2009ZX09503)
文摘Stability, specificity, and pharmacokinetic properties are some of the challenges facing RNAi therapeutics. In this review, the progresses in chemically modified siRNAs and siRNA conjugates are summarized. The proper modification of siRNA with nucleoside analogues, construction of siRNA conjugates, and reliable prediction of the property based on those strategies for a given siRNA sequence would certainly be an essential part of the solution to these challenges.
文摘Graphene has attracted the interest of chemists, physicists, and materials scientists due to its extraordinary structural, mechanical, and electronic properties. While pristine graphene is desirable for applications that require a high electrical conductivity, many other applications require modified or functionalized forms of graphene, such as graphene oxide, reduced graphene, or other functionalized forms. Structurally modifying graphene through chemical functionalization reveals the numerous possibilities for tuning its structure; several chemical and physical functionalization methods have been explored to improve the stabilization and modification of graphene. In this review, we report recent progress towards the chemical modification of graphene, including both covalent and noncovalent methods, for use in various applications.
基金The National Natural Science Foundation of China(Grant No.21572268)
文摘As a small catalytic DNA molecule, 10-23 DNAzyme has cleavage ability against complementary RNA. Previous studies of chemical modification have shown that its catalytic core can be further optimized in order to obtain more powerful catalytic ability. The analogues of 2＇-deoxyadenosine （5） and 2＇-deoxyguanosine （6） could improve the cleavage ability of the DNAzyme when positioned at positions A9, （32 and G14 in the catalytic core, respectively. Moreover, their combinatorial incorporations were studied, the results implicated that the effect was position-dependent, and positive additive results could be achieved at some positions. The highly conserved G1, G2 and G14 could be optimized by single or combinatorial modification with 2＇-deoxyguanosine analogues. Chemical modifications on the functional groups of the core residues would be a feasible approach for the optimization of 10-23 DNAzyme.
基金Australian Research Council(ARC)for funding received under the ARC Discovery Project scheme(DP180102752)the financial support via the ARC DECRA scheme(DE160100715)+1 种基金the support from the Shuguang Program supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(18SG035)State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Donghua University(KF2015)。
文摘Two-dimensional(2D)metal oxides and chalcogenides(MOs&MCs)have been regarded as a new class of promising electro-and photocatalysts for many important chemical reactions such as hydrogen evolution reaction,CO_(2) reduction reaction and N2 reduction reaction in virtue of their outstanding physicochemical properties.However,pristine 2D MOs&MCs generally show the relatively poor catalytic performances due to the low electrical conductivity,few active sites and fast charge recombination.Therefore,considerable efforts have been devoted to engineering 2D MOs&MCs by rational structural design and chemical modification to further improve the catalytic activities.Herein,we comprehensively review the recent advances for engineering technologies of 2D MOs&MCs,which are mainly focused on the intercalation,doping,defects creation,facet design and compositing with functional materials.Meanwhile,the relationship between morphological,physicochemical,electronic,and optical properties of 2D MOs&MCs and their electro-and photocatalytic performances is also systematically discussed.Finally,we further give the prospect and challenge of the field and possible future research directions,aiming to inspire more research for achieving high-performance 2D MOs&MCs catalysts in energy storage and conversion fields.
基金supported by the National Natural Science Foundation of China(52173189 and 22105208)。
文摘Device stability becomes one of the most crucial issues for the commercialization of organic solar cells(OSCs) after high power conversion efficiencies have been achieved. Besides the intrinsic stability of photoactive materials, the chemical/catalytic reaction between interfacial materials and photoactive materials is another critical factor that determines the stability of OSC devices. Herein, we design and synthesize a reaction-inert rylene diimide-embedded hyperbranched polymer named as PDIEIE, which effectively reduces the work function of indium tin oxide electrode from 4.62 to 3.65 eV. Meanwhile, PDIEIE shows negligible chemical reaction with high-performance photoactive materials and no catalytic effect under strong ultraviolet illumination, resulting in much better photo-stability of OSCs with PDIEIE cathode interlayer(CIL), relative to the traditional CILs, including most-widely used metal oxides and polyethyleneimine derivatives.
