Effects of collectors(butyl xanthate(BX), O-isopropyl-N-sulfur ethyl carbamate(Z-200) and emulsified kerosene), dereagent(sodium sulfide) and depressant thioglycollic acid(TGA) on the flotation of chalcocite and molyb...Effects of collectors(butyl xanthate(BX), O-isopropyl-N-sulfur ethyl carbamate(Z-200) and emulsified kerosene), dereagent(sodium sulfide) and depressant thioglycollic acid(TGA) on the flotation of chalcocite and molybdenite were investigated through flotation. The first principle theory was adopted to understand the difference of their surfaces and reaction between minerals and reagents. Results of flotation tests revealed that selectivity of emulsified kerosene is the best of three collectors in separation of chalcocite and molybdenite, though the others also display excellent collecting properties. Sodium sulfide can effectively remove collectors adsorbed on chalcocite surface, and TGA is an effective depressant of chalcocite at pH 8-9. Through first principle study, molybdenite displays relatively stronger covalence property while bonding interaction between copper atoms in chalcocite enhanced its ionicity. Bonding interaction is weaker in reaction of TGA and molybdenite, so it shows higher hydrophobicity and better flotability. Therefore, TGA is an effective inhibitor in the separation.展开更多
The title compounds, [Co（H2O）6]（OVA）2·2H2O 1, [Ni（H2O）6]（OVA）2·2H2O 2 and [Zn（OVA）2·2H2O] 3 （HOVA = o-vanillic acid = 2-hydroxy-3-methoxybenzoate）, were synthesized and characterized by sing...The title compounds, [Co（H2O）6]（OVA）2·2H2O 1, [Ni（H2O）6]（OVA）2·2H2O 2 and [Zn（OVA）2·2H2O] 3 （HOVA = o-vanillic acid = 2-hydroxy-3-methoxybenzoate）, were synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR and TGA. Compounds 1 and 2 are both of triclinic with space group P1. The metal atom coordinated by six water molecules displays a slightly distorted octahedral configuration. Interestingly, the carboxyl group from HOVA ligand does not coordinate to the metal atom. Correspondingly, compound 3 belongs to the monoclinic system, space group C2/c. Each zinc（Ⅱ） atom exhibits a distorted four-coordinated tetrahedral geometry. Two monodentate carboxyl groups link one zinc（Ⅱ） atom to form a mononuclear molecule. The structure feature is different from that of compounds 1 and 2, which could be attributed to the different coordinated numbers and radii of Co（Ⅱ）, Ni（Ⅱ） and Zn（Ⅱ） atoms.展开更多
In this letter, the self-assembling process of thioglycollic acid on gold in aqueous solutions was studied by QCM technique. Frequency information suggests bilayer or multilayer adsorbate formation in 0.5 mol/L HCl so...In this letter, the self-assembling process of thioglycollic acid on gold in aqueous solutions was studied by QCM technique. Frequency information suggests bilayer or multilayer adsorbate formation in 0.5 mol/L HCl solution but only monolayer one in 0.5 mol/L KOH solution. This phenomenon is explained by hydrogen bond effect.展开更多
Glycolic acid was polymerized under vacuum in the presence and absence of nano sized clay.The added clay catalyzed the condensation polymerization which can be confirmed by recording FTIR spectroscopy and intrinsic vi...Glycolic acid was polymerized under vacuum in the presence and absence of nano sized clay.The added clay catalyzed the condensation polymerization which can be confirmed by recording FTIR spectroscopy and intrinsic viscosity (Ⅳ)values.The relative intensity of C=O/CH is increased while increasing the amount of clay.DSC showed the appearance of multiple endotherms of poly(glycolic acid).TGA showed the percentage weight residue remain above 750℃for polymer-nano composite system was 21% and hence proved the fl...展开更多
Ni-mSA-mCS bipolar membrane （BM） was prepared by sodium alginate （SA） and chitosan （CS）, which were modified by Ca^2＋ and glutaraldehyde as linking reagents, respectively, mSA-mCS membrane was characterized by ...Ni-mSA-mCS bipolar membrane （BM） was prepared by sodium alginate （SA） and chitosan （CS）, which were modified by Ca^2＋ and glutaraldehyde as linking reagents, respectively, mSA-mCS membrane was characterized by FTIR, SEM, TG and used as a separator in the electrolysis cell to produce thioglycolic acid （TGA）. The experiment results show that TGAwas prepared effectively by electro-reduction of dithiodiglycolic acid （DTDGA） with the mixture of TGA and DTDGA in the cathodic chamber. The current efficiency was up to 66.7% at the room temperature （25 ℃） during the current density of 10 mA/cm^2. Compared with the traditional metal reduction method, the electro-reduction technology saves the zinc powder and eliminates the pollution to environment.展开更多
The terpolymer of itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization. The IR spectra confirmed that there was no olefinic band, while th...The terpolymer of itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization. The IR spectra confirmed that there was no olefinic band, while the TGA results revealed that the terpolymer was of high thermal stability.展开更多
The polyaddition of isocyanate and polyol to form polyurethane elastomers has rarely been applied to the construction of chiral polyurethane elastomers. Hence, the introduction of chiral units via polyaddition remains...The polyaddition of isocyanate and polyol to form polyurethane elastomers has rarely been applied to the construction of chiral polyurethane elastomers. Hence, the introduction of chiral units via polyaddition remains a challenging subject in polymer chemistry. In this study, the synthesis of chiral polyurethane elastomers using an aromatic isocyanate, polyols (polyether and polyester polyols), and L(+)-, D(−)-, or meso-tartaric acid by a one-shot method is investigated. The polymers are characterized using FTIR and NMR spectroscopy, and their thermal properties are investigated by TGA, DMA, and DSC analyses. The optical activities of the polymers are confirmed by rotation. The use of chiral tartaric acids is essential to obtain the desired chiral polyurethane elastomers.展开更多
Water-dispersible ZnSe quantum dots （ZnSe QDs） were prepared in aqueous media and characterized by ultraviolet-visible absorption, fluorescence emission spectroscopy, X-ray powder diffraction, transmission electron ...Water-dispersible ZnSe quantum dots （ZnSe QDs） were prepared in aqueous media and characterized by ultraviolet-visible absorption, fluorescence emission spectroscopy, X-ray powder diffraction, transmission electron microscopy, energydispersive spectroscopy, and inductively coupled plasma atomic emission spectroscopy. The influences of various experimental variables on the photoluminescence properties of ZnSe QDs were investigated. The results showed that the average diameter of these nanocrystals was 4 nm with narrow size distribution. The optimized conditions were as follows： pH value of 9.5, Zn/NaHSe molar ratio of 10：1, Zn/TGA molar ratio of 1：3, heating time of 1 h, and irradiation time of 19 h. Under optimized conditions, the photoluminescence quantum yield of ZnSe QDs in aqueous solution reached 20%.展开更多
Most luminescent glucose sensors based on the interaction of glucose with organic boric acids or borates.Herein,a new luminescent glucose sensor is designed using thioglycolic acid-capped CdTe quantum dots in the pres...Most luminescent glucose sensors based on the interaction of glucose with organic boric acids or borates.Herein,a new luminescent glucose sensor is designed using thioglycolic acid-capped CdTe quantum dots in the presence of cheap inorganic boric acid.Both peak position and intensities change upon the addition of glucose because of the interaction of boric acid with glucose and thioglycolic acid-capped CdTe quantum dots,which enables glucose detection by either color change or intensity change.The luminescent intensities change linearly with glucose concentrations in the ranges from 0.03 to 1 mM and 1–25 mM with a detection limit of 10μM(S/N=3).Moreover,glucose concentrations can be conveniently detected by color change in the range from 1 mM–25 mM.It displays a highly selective response to glucose over other interfering but biologically important saccharides,amino acids,and common ions.Graphical Abstract A thioglycolic acid-capped CdTe QD-based sensor can detect glucose with wide linear range by change in intensity or color in the presence of cheap inorganic boric acid.展开更多
基金provided by the National Natural Science Foundation of China(No.51274255)the Innovation Driven Plan of Central South University(No.2015CX005)+1 种基金the Postdoctoral Research Station of Central South UniversityCo-Innovation Centre for Clean and Efficient Utilization of Strategic Metal Mineral Resources
文摘Effects of collectors(butyl xanthate(BX), O-isopropyl-N-sulfur ethyl carbamate(Z-200) and emulsified kerosene), dereagent(sodium sulfide) and depressant thioglycollic acid(TGA) on the flotation of chalcocite and molybdenite were investigated through flotation. The first principle theory was adopted to understand the difference of their surfaces and reaction between minerals and reagents. Results of flotation tests revealed that selectivity of emulsified kerosene is the best of three collectors in separation of chalcocite and molybdenite, though the others also display excellent collecting properties. Sodium sulfide can effectively remove collectors adsorbed on chalcocite surface, and TGA is an effective depressant of chalcocite at pH 8-9. Through first principle study, molybdenite displays relatively stronger covalence property while bonding interaction between copper atoms in chalcocite enhanced its ionicity. Bonding interaction is weaker in reaction of TGA and molybdenite, so it shows higher hydrophobicity and better flotability. Therefore, TGA is an effective inhibitor in the separation.
基金supported by the National Natural Science Foundation of China (No. 20573073)the Natural Scientific Research Foundation of Shaanxi Provincial Education Office of China (No. 09JK826, 08JZ82 and 08JK490)
文摘The title compounds, [Co（H2O）6]（OVA）2·2H2O 1, [Ni（H2O）6]（OVA）2·2H2O 2 and [Zn（OVA）2·2H2O] 3 （HOVA = o-vanillic acid = 2-hydroxy-3-methoxybenzoate）, were synthesized and characterized by single-crystal X-ray diffraction, elemental analysis, IR and TGA. Compounds 1 and 2 are both of triclinic with space group P1. The metal atom coordinated by six water molecules displays a slightly distorted octahedral configuration. Interestingly, the carboxyl group from HOVA ligand does not coordinate to the metal atom. Correspondingly, compound 3 belongs to the monoclinic system, space group C2/c. Each zinc（Ⅱ） atom exhibits a distorted four-coordinated tetrahedral geometry. Two monodentate carboxyl groups link one zinc（Ⅱ） atom to form a mononuclear molecule. The structure feature is different from that of compounds 1 and 2, which could be attributed to the different coordinated numbers and radii of Co（Ⅱ）, Ni（Ⅱ） and Zn（Ⅱ） atoms.
文摘In this letter, the self-assembling process of thioglycollic acid on gold in aqueous solutions was studied by QCM technique. Frequency information suggests bilayer or multilayer adsorbate formation in 0.5 mol/L HCl solution but only monolayer one in 0.5 mol/L KOH solution. This phenomenon is explained by hydrogen bond effect.
文摘Glycolic acid was polymerized under vacuum in the presence and absence of nano sized clay.The added clay catalyzed the condensation polymerization which can be confirmed by recording FTIR spectroscopy and intrinsic viscosity (Ⅳ)values.The relative intensity of C=O/CH is increased while increasing the amount of clay.DSC showed the appearance of multiple endotherms of poly(glycolic acid).TGA showed the percentage weight residue remain above 750℃for polymer-nano composite system was 21% and hence proved the fl...
基金supported by the Nature Science Foundations of Fujian Province(No.D0710009)the Fujian Education Bureau(Nos.JB06069,JB05314).
文摘Ni-mSA-mCS bipolar membrane （BM） was prepared by sodium alginate （SA） and chitosan （CS）, which were modified by Ca^2＋ and glutaraldehyde as linking reagents, respectively, mSA-mCS membrane was characterized by FTIR, SEM, TG and used as a separator in the electrolysis cell to produce thioglycolic acid （TGA）. The experiment results show that TGAwas prepared effectively by electro-reduction of dithiodiglycolic acid （DTDGA） with the mixture of TGA and DTDGA in the cathodic chamber. The current efficiency was up to 66.7% at the room temperature （25 ℃） during the current density of 10 mA/cm^2. Compared with the traditional metal reduction method, the electro-reduction technology saves the zinc powder and eliminates the pollution to environment.
文摘The terpolymer of itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization. The IR spectra confirmed that there was no olefinic band, while the TGA results revealed that the terpolymer was of high thermal stability.
文摘The polyaddition of isocyanate and polyol to form polyurethane elastomers has rarely been applied to the construction of chiral polyurethane elastomers. Hence, the introduction of chiral units via polyaddition remains a challenging subject in polymer chemistry. In this study, the synthesis of chiral polyurethane elastomers using an aromatic isocyanate, polyols (polyether and polyester polyols), and L(+)-, D(−)-, or meso-tartaric acid by a one-shot method is investigated. The polymers are characterized using FTIR and NMR spectroscopy, and their thermal properties are investigated by TGA, DMA, and DSC analyses. The optical activities of the polymers are confirmed by rotation. The use of chiral tartaric acids is essential to obtain the desired chiral polyurethane elastomers.
基金Supported by the National High Technology Research and Development Program of China (863 Program) (2007AA06Z418)the Fundamental Research Funds for the Central Universities
文摘Water-dispersible ZnSe quantum dots （ZnSe QDs） were prepared in aqueous media and characterized by ultraviolet-visible absorption, fluorescence emission spectroscopy, X-ray powder diffraction, transmission electron microscopy, energydispersive spectroscopy, and inductively coupled plasma atomic emission spectroscopy. The influences of various experimental variables on the photoluminescence properties of ZnSe QDs were investigated. The results showed that the average diameter of these nanocrystals was 4 nm with narrow size distribution. The optimized conditions were as follows： pH value of 9.5, Zn/NaHSe molar ratio of 10：1, Zn/TGA molar ratio of 1：3, heating time of 1 h, and irradiation time of 19 h. Under optimized conditions, the photoluminescence quantum yield of ZnSe QDs in aqueous solution reached 20%.
基金the National Natural Science Foundation of China(Nos.21475123 and 21505128)Chinese Academy of Sciences(CAS)and Faculty Development Program of the Bahauddin Zakaryia University,Multan,Pakistan(100 Foreign Scholarships)(No.PF/Cont./2-50/Admin/5398).
文摘Most luminescent glucose sensors based on the interaction of glucose with organic boric acids or borates.Herein,a new luminescent glucose sensor is designed using thioglycolic acid-capped CdTe quantum dots in the presence of cheap inorganic boric acid.Both peak position and intensities change upon the addition of glucose because of the interaction of boric acid with glucose and thioglycolic acid-capped CdTe quantum dots,which enables glucose detection by either color change or intensity change.The luminescent intensities change linearly with glucose concentrations in the ranges from 0.03 to 1 mM and 1–25 mM with a detection limit of 10μM(S/N=3).Moreover,glucose concentrations can be conveniently detected by color change in the range from 1 mM–25 mM.It displays a highly selective response to glucose over other interfering but biologically important saccharides,amino acids,and common ions.Graphical Abstract A thioglycolic acid-capped CdTe QD-based sensor can detect glucose with wide linear range by change in intensity or color in the presence of cheap inorganic boric acid.
