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2016 Volume 79 Issue 2
2016, 79(2): 99-105
Abstract:
PAMAM is the dendrimer with most possible application foreground. The aggregate can be formed after the interaction between dendrimer and surfactant; it can effectively improve the micro environment and physicochemical properties of the system. This paper summarizes the recent progress in the interaction between dendrimer and surfactant, and emphatically discusses on the changes of physicochemical properties, such as, the hydrophobic environment, turbidity and median diameter of aggregation in the mixed system of dendrimer and ionic surfactant. On this basis, the paper discusses the research progress in mechanism of the interaction between dendrimer and surfactant. The authors hope this paper can supply reference for further expanding the field of dendrimer.
PAMAM is the dendrimer with most possible application foreground. The aggregate can be formed after the interaction between dendrimer and surfactant; it can effectively improve the micro environment and physicochemical properties of the system. This paper summarizes the recent progress in the interaction between dendrimer and surfactant, and emphatically discusses on the changes of physicochemical properties, such as, the hydrophobic environment, turbidity and median diameter of aggregation in the mixed system of dendrimer and ionic surfactant. On this basis, the paper discusses the research progress in mechanism of the interaction between dendrimer and surfactant. The authors hope this paper can supply reference for further expanding the field of dendrimer.
2016, 79(2): 106-110
Abstract:
Dye-sensitized solar cells (DSSC) have attracted great attention due to their ease of fabrication, low cost, and high light-to-electricity conversion efficiencies compared with those of commercial silicon solar cells. In this paper, the effects of the donor, substituent group, bridge (π) and acceptor of meso-D-π-A porphyrin dyes on the DSSC performances were summarized.
Dye-sensitized solar cells (DSSC) have attracted great attention due to their ease of fabrication, low cost, and high light-to-electricity conversion efficiencies compared with those of commercial silicon solar cells. In this paper, the effects of the donor, substituent group, bridge (π) and acceptor of meso-D-π-A porphyrin dyes on the DSSC performances were summarized.
2016, 79(2): 111-117
Abstract:
The wound dressings can protect wounds, control infection and promote wounds healing when skin is damaged. In this paper, firstly, the selection criteria and classification of ideal wound dressings are introduced. Then, the studies on the natural polymer wound dressing materials are summarized according to structural characteristics and applications. Polysaccharides including cellulose, alginates, chitin, chitosan, agar, pectin, gum, glycosaminoglycans and so on can be used as wound dressings. Protein based wound dressings are mainly classified as plant proteins and animal proteins. In the future, the researches and applications of wound dressings will be greatly promoted with the development of polymer synthesis technology and controlled drug delivery technology.
The wound dressings can protect wounds, control infection and promote wounds healing when skin is damaged. In this paper, firstly, the selection criteria and classification of ideal wound dressings are introduced. Then, the studies on the natural polymer wound dressing materials are summarized according to structural characteristics and applications. Polysaccharides including cellulose, alginates, chitin, chitosan, agar, pectin, gum, glycosaminoglycans and so on can be used as wound dressings. Protein based wound dressings are mainly classified as plant proteins and animal proteins. In the future, the researches and applications of wound dressings will be greatly promoted with the development of polymer synthesis technology and controlled drug delivery technology.
2016, 79(2): 118-122,128
Abstract:
Cellulose is the most abundant organic raw material and renewable resource in the nature. As a high active biocatalyst, cellulase plays an important role in the utilization of cellulosic resources. This paper summarizes molecular structures of cellulose and cellulase, mechanism of cellulose degradation by cellulase, and main influence factors on enzyme activity and methods of enhancing hydrolysis efficiency of cellulose. Finally, the problems and the future prospect in the research on cellulase are discussed.
Cellulose is the most abundant organic raw material and renewable resource in the nature. As a high active biocatalyst, cellulase plays an important role in the utilization of cellulosic resources. This paper summarizes molecular structures of cellulose and cellulase, mechanism of cellulose degradation by cellulase, and main influence factors on enzyme activity and methods of enhancing hydrolysis efficiency of cellulose. Finally, the problems and the future prospect in the research on cellulase are discussed.
2016, 79(2): 123-128
Abstract:
As a type of environmentally friendly catalyst, nickel-based amorphous alloy catalysts exhibit good catalytic performance and possess some characters such as high activity, high selectivity, low prices etc. It is widely used in the fields of the catalytic hydrogenation of unsaturated compounds, compound desulfurization, hydrolysis of borohydride, fuel cells electro-catalytic oxidation and so on. The structural characteristics of nickel-based amorphous alloy catalysts and the research status at home and abroad in recent years are summarized. Meanwhile, the effects of addition of metal, supports and preparation methods on the performance of the nickel-based amorphous alloy catalysts are emphasized, and its future research directions are analyzed and prospected.
As a type of environmentally friendly catalyst, nickel-based amorphous alloy catalysts exhibit good catalytic performance and possess some characters such as high activity, high selectivity, low prices etc. It is widely used in the fields of the catalytic hydrogenation of unsaturated compounds, compound desulfurization, hydrolysis of borohydride, fuel cells electro-catalytic oxidation and so on. The structural characteristics of nickel-based amorphous alloy catalysts and the research status at home and abroad in recent years are summarized. Meanwhile, the effects of addition of metal, supports and preparation methods on the performance of the nickel-based amorphous alloy catalysts are emphasized, and its future research directions are analyzed and prospected.
2016, 79(2): 129-134
Abstract:
Many living organisms have the instinct that can allow them to alter their properties in response to the stimulation around environments. In the biological realm, light can promote both the positive and negative phototaxis as a powerful stimulus. A one-dimensional active BZ gel was designed; the oscillation frequency of the gel can be controlled by the photosensivity of the BZ reaction catalyzed by Ru-catalyst, which drives the move of gel directionally. At the same time, a responsive gel model proposed by Yashin was modified to simulate the relation between the light intensity and the oscillation frequency of BZ reaction and explain the mechanism of self-sustain motion of active BZ gel. The results may help to design novel smart bionic robot for studying the response to the stimulation from outside environments.
Many living organisms have the instinct that can allow them to alter their properties in response to the stimulation around environments. In the biological realm, light can promote both the positive and negative phototaxis as a powerful stimulus. A one-dimensional active BZ gel was designed; the oscillation frequency of the gel can be controlled by the photosensivity of the BZ reaction catalyzed by Ru-catalyst, which drives the move of gel directionally. At the same time, a responsive gel model proposed by Yashin was modified to simulate the relation between the light intensity and the oscillation frequency of BZ reaction and explain the mechanism of self-sustain motion of active BZ gel. The results may help to design novel smart bionic robot for studying the response to the stimulation from outside environments.
2016, 79(2): 135-140
Abstract:
The macrocyclic triamine derivative ligand N,N',N"-tris(2-hydroxypropyl)-1,4,7-triazacyclodecane (L) and its four transition metal complexes[ML]·[ClO4]2 (M=Zn2+, Cu2+, Ni2+, Co2+) were synthesized and characterized. The complexes possess similar structures. Furthermore, their activities for promoting hydrolysis of 4-nitrophenyl acetate (NA) were also investigated. The results indicated that the kNA for complexes of Zn2+, Cu2+, Ni2+ and Co2+ at pH 7.53 and 25℃ are 22770, 7478, 6331 and 2531 mmol-1·L·s-1, respectively, the activity order of center metal for introducing the hydrolysis of NA is Zn > Cu > Ni > Co.
The macrocyclic triamine derivative ligand N,N',N"-tris(2-hydroxypropyl)-1,4,7-triazacyclodecane (L) and its four transition metal complexes[ML]·[ClO4]2 (M=Zn2+, Cu2+, Ni2+, Co2+) were synthesized and characterized. The complexes possess similar structures. Furthermore, their activities for promoting hydrolysis of 4-nitrophenyl acetate (NA) were also investigated. The results indicated that the kNA for complexes of Zn2+, Cu2+, Ni2+ and Co2+ at pH 7.53 and 25℃ are 22770, 7478, 6331 and 2531 mmol-1·L·s-1, respectively, the activity order of center metal for introducing the hydrolysis of NA is Zn > Cu > Ni > Co.
2016, 79(2): 141-146
Abstract:
A ternary complex of rare earth ion, Sm2(Asp)2(Im)6(ClO4)6·6H2O, was synthesized and its thermodynamic properties were studied. Molar heat capacities at constant pressure (Cp,m) of the complex were measured with a high-precision automatic adiabatic calorimeter over the temperature range from 80 to 390 K, and the thermodynamic functions (HT-H298.15 and ST-S298.15) were derived from the heat capacity data with temperature interval of 5 K. The phase transitions of the new complex around 220 K and 245 K were discovered both by adiabatic calorimetry and differential scanning calorimetry (DSC). The thermodynamic data of the phase transitions were calculated and the mechanism of phase transitions was deduced to be the reorientation process of perchlorate ions in the complex. Thermal stability of the complex was tested by thermogravimetric (TG) technique and a possible mechanism for the decomposition was suggested.
A ternary complex of rare earth ion, Sm2(Asp)2(Im)6(ClO4)6·6H2O, was synthesized and its thermodynamic properties were studied. Molar heat capacities at constant pressure (Cp,m) of the complex were measured with a high-precision automatic adiabatic calorimeter over the temperature range from 80 to 390 K, and the thermodynamic functions (HT-H298.15 and ST-S298.15) were derived from the heat capacity data with temperature interval of 5 K. The phase transitions of the new complex around 220 K and 245 K were discovered both by adiabatic calorimetry and differential scanning calorimetry (DSC). The thermodynamic data of the phase transitions were calculated and the mechanism of phase transitions was deduced to be the reorientation process of perchlorate ions in the complex. Thermal stability of the complex was tested by thermogravimetric (TG) technique and a possible mechanism for the decomposition was suggested.
2016, 79(2): 147-151
Abstract:
The magnetic γ-Fe2O3/BiOCl/BiVO4 composite photocatalyst was successfully synthesized by a simple ultrasound-hydrothermal method. The crystalline structures, morphologies and optical properties of the γ-Fe2O3/BiOCl/BiVO4 composite photocatalyst were characterized by X-ray powder diffraction, SEM and UV-Vis DRS. The as-prepared micron massive of BiVO4 with average diameters of 1.5~2.0 μm were constructed by BiOCl/BiVO4 nanosheets decorated by γ-Fe2O3 nanoparticles. The photocatalytic activities of γ-Fe2O3/BiOCl/BiVO4 were evaluated via the photodegradation of rhodamine B under visible-light radiation. The results showed that the 15% γ-Fe2O3/BiOCl/BiVO4 composite photocatalyst can be easily separated from the reaction solution by external magnetic field, and the composite photocatalyst has high visible light catalytic activity and stability, the degradation rate of rhodamine B and light catalyst recovery rate can still be reached to 88.6% and 90.3% after used 4 times. It has potential applications in water treatment and environmental cleaning.
The magnetic γ-Fe2O3/BiOCl/BiVO4 composite photocatalyst was successfully synthesized by a simple ultrasound-hydrothermal method. The crystalline structures, morphologies and optical properties of the γ-Fe2O3/BiOCl/BiVO4 composite photocatalyst were characterized by X-ray powder diffraction, SEM and UV-Vis DRS. The as-prepared micron massive of BiVO4 with average diameters of 1.5~2.0 μm were constructed by BiOCl/BiVO4 nanosheets decorated by γ-Fe2O3 nanoparticles. The photocatalytic activities of γ-Fe2O3/BiOCl/BiVO4 were evaluated via the photodegradation of rhodamine B under visible-light radiation. The results showed that the 15% γ-Fe2O3/BiOCl/BiVO4 composite photocatalyst can be easily separated from the reaction solution by external magnetic field, and the composite photocatalyst has high visible light catalytic activity and stability, the degradation rate of rhodamine B and light catalyst recovery rate can still be reached to 88.6% and 90.3% after used 4 times. It has potential applications in water treatment and environmental cleaning.
2016, 79(2): 152-156
Abstract:
The one-dimensional supermolecular coordination polymer[Co5(C5N2O4H)4(C5N2O4H3)2(C12N2H8)4(H2O)2]·(H2O)6 (1) was synthesized by using 4,5-imidazoledicarboxylic acid and Co(NO3)2·6H2O under hydrothermal condition. Single-crystal X-ray analysis revealed that compound 1 crystallizes in the triclinic system, P1 space group with Mr=2082.09, a=13.104(3) Å, b=13.463(3) Å, c=13.708(3) Å, α=75.03(3)o, β=70.00(3)°, γ=65.39(3)° and V=2046.9 (10) Å3. In compound 1, Co4Ⅲ squares and CoⅡ octahedral units are connected with each other via strong hydrogen bonds interactions to construct an one-dimension supermolecular structure. CCDC:977802. Compound 1 was also characterized by PXRD, TGA, IR and elemental analyses.
The one-dimensional supermolecular coordination polymer[Co5(C5N2O4H)4(C5N2O4H3)2(C12N2H8)4(H2O)2]·(H2O)6 (1) was synthesized by using 4,5-imidazoledicarboxylic acid and Co(NO3)2·6H2O under hydrothermal condition. Single-crystal X-ray analysis revealed that compound 1 crystallizes in the triclinic system, P1 space group with Mr=2082.09, a=13.104(3) Å, b=13.463(3) Å, c=13.708(3) Å, α=75.03(3)o, β=70.00(3)°, γ=65.39(3)° and V=2046.9 (10) Å3. In compound 1, Co4Ⅲ squares and CoⅡ octahedral units are connected with each other via strong hydrogen bonds interactions to construct an one-dimension supermolecular structure. CCDC:977802. Compound 1 was also characterized by PXRD, TGA, IR and elemental analyses.
2016, 79(2): 157-163
Abstract:
A series of mesoporous graphitic carbon nitride materials (CND-SBA15) with tunable surface areas and pore volumes have been prepared using dicyandiamide as a precursor and SBA-15 samples as templates under different hydrothermal temperatures. The textual properties, microscopic morphology, porous orderness, chemical compositions, and basic properties of CND-SBA15 materials were characterized by N2 adsorption-desorption, TEM, small angle XRD, XPS, FT-IR, and CO2-TPD. It has been demonstrated that CND-SBA15 materials exhibit high activity and stability for catalyzing Knoevenagel condensation reaction between benzyl aldehyde and malononitrile.
A series of mesoporous graphitic carbon nitride materials (CND-SBA15) with tunable surface areas and pore volumes have been prepared using dicyandiamide as a precursor and SBA-15 samples as templates under different hydrothermal temperatures. The textual properties, microscopic morphology, porous orderness, chemical compositions, and basic properties of CND-SBA15 materials were characterized by N2 adsorption-desorption, TEM, small angle XRD, XPS, FT-IR, and CO2-TPD. It has been demonstrated that CND-SBA15 materials exhibit high activity and stability for catalyzing Knoevenagel condensation reaction between benzyl aldehyde and malononitrile.
2016, 79(2): 164-169
Abstract:
A heterocyclic corrosion inhibitor with surface activity was synthesized from 2-aminobenzimidazole, cyanuric chloride, hexanamine and N,N-dimethyl-1,3-propanediamine. Its surface activity was studied through the surface tensions measurement of its hydrochloric acid (HCl) solution with different concentrations. Weight loss method and electrochemical measurements (including potentiodynamic polarization and electrochemical impedance spectroscopy) were used to investigate the inhibition action of the synthesized inhibitor as well as 2-amino-benzimidazole on carbon steel in HCl solution. SEM was used to observe the surface morphology of the test specimens in the weight loss measurement. Results showed that surface activity of as-synthesized inhibitor and the introduced multi-active adsorption centers in it improve its adsorption ability on carbon steel surface, so its inhibition efficiency is better significantly than that of 2-aminobenzimidazole. Inhibition efficiency of the inhibitor increased with increase of its concentrations. The electrochemical measurements showed that the inhibitor was a mixed-type inhibitor.
A heterocyclic corrosion inhibitor with surface activity was synthesized from 2-aminobenzimidazole, cyanuric chloride, hexanamine and N,N-dimethyl-1,3-propanediamine. Its surface activity was studied through the surface tensions measurement of its hydrochloric acid (HCl) solution with different concentrations. Weight loss method and electrochemical measurements (including potentiodynamic polarization and electrochemical impedance spectroscopy) were used to investigate the inhibition action of the synthesized inhibitor as well as 2-amino-benzimidazole on carbon steel in HCl solution. SEM was used to observe the surface morphology of the test specimens in the weight loss measurement. Results showed that surface activity of as-synthesized inhibitor and the introduced multi-active adsorption centers in it improve its adsorption ability on carbon steel surface, so its inhibition efficiency is better significantly than that of 2-aminobenzimidazole. Inhibition efficiency of the inhibitor increased with increase of its concentrations. The electrochemical measurements showed that the inhibitor was a mixed-type inhibitor.
2016, 79(2): 170-174
Abstract:
Allicin entrapping beads (AEBs) with a porous microstructure were prepared by entrapping allicin into alginate beads for investigating the quorum quenching (QQ) effect of allicin to the mixed liquor filterability in membrane bioreactor (MBR). The results showed that the QQ of allicin has a significant impact on the characteristics of activated sludge, whereas there is no obviously impact on the removal of pollutants in MBR. It was observed that the content of extracellular polymeric substances (EPS), soluble microbial products (SMP) as well as the modified fouling index (MFI) values were obviously decreased compared to the MBR-control, which indicated that the addition of AEBs would benefit to improve the filterability of activated sludge in MBR. Moreover, the formation ability of biofilm on the membrane surface was reduced by adding AEBs in MBR.
Allicin entrapping beads (AEBs) with a porous microstructure were prepared by entrapping allicin into alginate beads for investigating the quorum quenching (QQ) effect of allicin to the mixed liquor filterability in membrane bioreactor (MBR). The results showed that the QQ of allicin has a significant impact on the characteristics of activated sludge, whereas there is no obviously impact on the removal of pollutants in MBR. It was observed that the content of extracellular polymeric substances (EPS), soluble microbial products (SMP) as well as the modified fouling index (MFI) values were obviously decreased compared to the MBR-control, which indicated that the addition of AEBs would benefit to improve the filterability of activated sludge in MBR. Moreover, the formation ability of biofilm on the membrane surface was reduced by adding AEBs in MBR.
2016, 79(2): 175-178
Abstract:
Mo (VI) in water was pre-concentrated by the diffusive gradients in thin-films (DGT) technique with poly (quaternary ammonium salt) (PQAS) as binding phase (PQAS DGT) and measured by potassium thiocyanate (PT) spectrophotometry. The recoveries of Mo (VI) in the synthetic solutions measured by the DGT-PT method were 96.3%~101.3% with RSD of 1.3%~4.0%. The concentration of Mo (VI) in industrial wastewaters measured by the DGT-PT method was 27.13~121.79 μg/L with recoveries of 96.0%~101.6%. The enrichment factor of Mo (VI) pre-concentrated by PQAS DGT was 18 when deployment time of 48 h. Therefore, the DGT-PT method can be used to measure traces Mo (VI) in water.
Mo (VI) in water was pre-concentrated by the diffusive gradients in thin-films (DGT) technique with poly (quaternary ammonium salt) (PQAS) as binding phase (PQAS DGT) and measured by potassium thiocyanate (PT) spectrophotometry. The recoveries of Mo (VI) in the synthetic solutions measured by the DGT-PT method were 96.3%~101.3% with RSD of 1.3%~4.0%. The concentration of Mo (VI) in industrial wastewaters measured by the DGT-PT method was 27.13~121.79 μg/L with recoveries of 96.0%~101.6%. The enrichment factor of Mo (VI) pre-concentrated by PQAS DGT was 18 when deployment time of 48 h. Therefore, the DGT-PT method can be used to measure traces Mo (VI) in water.
Electrical Conductivity of Tetrabutylammonium Fluoride in water-N,N-Dimethyl Formamide Mixed Solvent
2016, 79(2): 179-182
Abstract:
Conductance measurements at temperatures range from 298.15 to 328.15k were performed for tetrabutylammonium fluoride (TBAF) in 20(wt)%~80(wt)% water/DMF mixtures. The conductivity data had been analyzed using Kraus-Bray and Shedlovsky models, the limiting equivalent conductance, the association constants, dissociation constants and thermodynamic parameters of association(△Ga,△Ha,△Sa) for TBAF were calculated and discussed based on the effect of the temperature and the composition of solvent mixture on them.
Conductance measurements at temperatures range from 298.15 to 328.15k were performed for tetrabutylammonium fluoride (TBAF) in 20(wt)%~80(wt)% water/DMF mixtures. The conductivity data had been analyzed using Kraus-Bray and Shedlovsky models, the limiting equivalent conductance, the association constants, dissociation constants and thermodynamic parameters of association(△Ga,△Ha,△Sa) for TBAF were calculated and discussed based on the effect of the temperature and the composition of solvent mixture on them.
2016, 79(2): 183-186
Abstract:
Based upon the author's practical experience in patent assessment, this article summarizes the frequently occurring problems by the Chinese universities and research institutions during patent application document writing, for examples, insufficient disclosure of description, non necessary technical features in claims, lack definition of technical terms, etc. The authors also put forward some solutions for eliminating these influences. It aims to facilitate the researchers writing proper patent application documents, hence better protecting the applicant's rights and interests.
Based upon the author's practical experience in patent assessment, this article summarizes the frequently occurring problems by the Chinese universities and research institutions during patent application document writing, for examples, insufficient disclosure of description, non necessary technical features in claims, lack definition of technical terms, etc. The authors also put forward some solutions for eliminating these influences. It aims to facilitate the researchers writing proper patent application documents, hence better protecting the applicant's rights and interests.
2016, 79(2): 187-191
Abstract:
Titration curve plays a key role in quantitative chemical analysis with useful and easily acquirable information. A method was proposed in this paper to plot accurate titration curves by means of inverse or implicit functions. Inverse or implicit functions are easier than general ones in both derivation and programming implementation. Consequently, a large number of data points are readily obtained without much demand on either mathematical or programming knowledge, which results in highly accurate titration curves. The proposed method is effective for all sorts of chemical equilibrium systems, particularly for those that traditional methods are incapable of. With highly accurate titration curves, tasks are readily implemented, such as choosing indicators, assessing a titration scheme, calculating titration errors, and evaluating factors in titration. This research is a part of a project to introduce computer-based approaches into the curriculum of analytical chemistry.
Titration curve plays a key role in quantitative chemical analysis with useful and easily acquirable information. A method was proposed in this paper to plot accurate titration curves by means of inverse or implicit functions. Inverse or implicit functions are easier than general ones in both derivation and programming implementation. Consequently, a large number of data points are readily obtained without much demand on either mathematical or programming knowledge, which results in highly accurate titration curves. The proposed method is effective for all sorts of chemical equilibrium systems, particularly for those that traditional methods are incapable of. With highly accurate titration curves, tasks are readily implemented, such as choosing indicators, assessing a titration scheme, calculating titration errors, and evaluating factors in titration. This research is a part of a project to introduce computer-based approaches into the curriculum of analytical chemistry.
