A series of stearates with different rare-earth ion were investigated as thermal stabilizers for rigid PVC at 180 ℃ in air. Their stabilizing efficiency was based on measuring the rate of dehydrochlorination. The res...A series of stearates with different rare-earth ion were investigated as thermal stabilizers for rigid PVC at 180 ℃ in air. Their stabilizing efficiency was based on measuring the rate of dehydrochlorination. The resulted revealed the higher stabilizing efficiency of the investigated rare-earth stearates as thermal stabilizers for rigid PVC compared with the thermal stabilizers for industry: calcium stearate, zinc stearate, butyl stannum mercaptide, phosphite esters, β-diketone and epoxidized sunflower oil. This was well illustrated by longer incubation period (T_S) values and lower rate of dehydrochlorination. The stable efficiency was affected by the nature of rare-earth element's individual electronic shell. The mechanism for the stabilizing effect of rare-earth stearates was proposed. The result was experimentally proved based on IR spectrum.展开更多
Waste shell stacking with odor and toxicity is a serious hazard to our living environment. To make effective use of the natural resources, the shell powder was applied as a filler of outdoor thermal insulation coating...Waste shell stacking with odor and toxicity is a serious hazard to our living environment. To make effective use of the natural resources, the shell powder was applied as a filler of outdoor thermal insulation coatings. Sodium stearate(SS) was used to modify the properties of shell powder to reduce its agglomeration and to increase its compatibility with the emulsion. The oil absorption rate and the spectrum reflectance of the shell powder show that the optimized content of SS as a modifier is 1.5wt%. The total spectrum reflectance of the coating made with the shell powder that is modified at this optimum SS content is 9.33% higher than that without any modification. At the optimum SS content of 1.5wt%, the thermal insulation of the coatings is improved by 1.0℃ for the cement mortar board and 1.6℃ for the steel plate, respectively. The scouring resistance of the coating with the 1.5wt% SS-modified shell powder is three times that of the coating without modification.展开更多
In this study, the barite nanoparticles were successfully modified with stearate and the influence of stearate addition on the performance of barite nanoparticles was systematically investigated. The products were cha...In this study, the barite nanoparticles were successfully modified with stearate and the influence of stearate addition on the performance of barite nanoparticles was systematically investigated. The products were characterized by activating factor analysis, contact angle test, surface energy calculation, sedimentation rate calculation, rheological measurement, and FT-IR analysis, etc. As the quantity of added stearate increased, both the activating factor and contact angle of barite nanoparticles increased first then decreased. When the stearate content was 5% of the mass of barite nanoparticles, the activating factor and water contact angle of modified particles reached maximum value, 97% and 126% respectively. At this time, the sedimentation rate reached minimum, and so did the surface energy. The rheological test reveals that the viscosity of modified barite nanoparticles/petronol system decreases greatly, indicating the surface performance of barite nanoparticles has changed from hydrophilicity to lipophilicity after modification. C=O and COO stretching vibration peaks were found in the FT-IR spectra, which proves that the stearate has combined onto the surface of barite nanoparticles. Finally, according to the zeta potential result of unmodified barite, the possible modification mechanism was provided.展开更多
Epigallocatechin gallate (EGCG), a green tea polyphenol possesses antioxidant, antibacterial, anticancer and antiviral properties. EGCG-Stearate (EGCG-S) is of interest for this study because of its stability and lipo...Epigallocatechin gallate (EGCG), a green tea polyphenol possesses antioxidant, antibacterial, anticancer and antiviral properties. EGCG-Stearate (EGCG-S) is of interest for this study because of its stability and lipophilic properties. The chemical modification of EGCG-S increased its lipid solubility. Herpes simplex virus-1 (HSV-1), a member of the family Herpesviridae, and Alphaherpesvirinae subfamily is a leading cause of human viral diseases in the United States. In this study, 25 μM, 50 μM, 75 μM, and 100 μM of EGCG and EGCG-S were used to carry out cytotoxicity, cell viability and cell proliferation assays to determine the maximum non-cytotoxic concentrations on cultured A549 cells. The results suggested that 75 μM of EGCG and EGCG-S is the appropriate concentration to further study the effect on the infection of HSV-1 in A549 cells. Infectivity, antiviral, and inverted microscopy assays were performed to study the effects of EGCG and EGCG-S on HSV-1 infection. An antiviral assay was performed using luminescence and it indicated that EGCG-S treated HSV-1 showed up to 90% inhibition. Confocal microscopy images further supported the inhibitory effects of 75 μM EGCG-S on HSV-1 infection in A549 cells. The long-term goal of this research is to use EGCG-S as a possible novel topical therapeutic treatment to limit the spread of HSV-1 infections.展开更多
Objective:To perform phytochemical analyses on the leaves of Ocimum basilicum L.(O.basilicum),to elucidate the structure of isolate and then perform the antisickling activity on the crude extract and on the isolate.Me...Objective:To perform phytochemical analyses on the leaves of Ocimum basilicum L.(O.basilicum),to elucidate the structure of isolate and then perform the antisickling activity on the crude extract and on the isolate.Methods:The Emmel test performed on the acidified methanolic extract of this plant was used to evaluate the antisickling activity.The structure characterization of the active compound was performed using chromatographic techniques for the separation and the spectroscopic ones for structure elucidation(1H-NMR,13C-NMR.COSY,HMBC).Resurte:The chemical screening on the crude extract revealed the presence of polyphenols(flavonoids,anthocyanins,leucoanthocyanins,tannins,quinones) alkaloids,saponins,triterpenoids and steroids.The ohtained extract after evaporation yielded 34.50g(11.5%) out of 300g of powdered leaves of O.basilicum.The acidified methanolic extract and butyl stearate showed an interesting antisickling activity.Conchisions:The acidified methanolic extract and butyl stearate from O.basilicum displayed a good antisickling activity.To the best of our knowledge,this is the first time to report the antisickling activity of this compound in this plant.The synmesized compound presented the same spectroscopic characteristics than the natural one and the antisickling activities of its derivatives are understudying.展开更多
Glycerol stearate was synthesized by esterification with non-toxic,inexpensive glycerol and stearic acid.The composite of glycerol stearate and Pinus radiata wood was prepared by vacuum impregnation.By Fourier transfo...Glycerol stearate was synthesized by esterification with non-toxic,inexpensive glycerol and stearic acid.The composite of glycerol stearate and Pinus radiata wood was prepared by vacuum impregnation.By Fourier transform infrared(FTIR)analysis,there was the generation of new C=O stretching vibration band of glycerol stearate in comparison with stearic acid.This confirms that glycerol stearate was successfully synthesized.The weight gain,FTIR spectrum and morphological analyses of the composite indicate that glycerol stearate was impregnated into the interior lumina of the cells.Thermal analysis showed that the maximal degradation temperature of the composite was 42℃higher than untreated wood.Contact angle images indicated that the value of the composite was134.2°.Hydrophobicity(the repulsion of water)of the composite was stronger than glycerol stearate,which a large number of hydroxyl of wood reacted with the oxygen-containing groups of glycerol stearate,improved hydrophobicity and thermal stability,thereby enhancing the potential application of P.radiata wood.展开更多
For thermal energy storage application in energy-saving building materials,silica microcapsules containing phase change material were prepared using sol-gel method in O/W emulsion system. In the system droplets in mic...For thermal energy storage application in energy-saving building materials,silica microcapsules containing phase change material were prepared using sol-gel method in O/W emulsion system. In the system droplets in microns are formed by emulsifying an organic phase consisting of butyl-stearate as core material. The silica shell was formed via hydrolysis and condensation from tetraethyl silicate with acetate as catalyst. The SEM photographs show the particles possess spherical morphology and core-shell structure. The as-prepared silica microcapsules mainly consist of microsphere in the diameter of 3-7 μm and the median diameter of these microcapsules equals to 5.2 μm. The differential scanning calorimetry(DSC) curves indicate that the latent heat and the melting point of microcapsules are 86 J/g and 22.6 ℃,respectively. The results of DSC and TG further testify the microcapsules with core-shell structure.展开更多
The usability of polyoxyethylene stearate with 10 ethylene epoxides(POES 10) as lubricant in warp sizing was investigated for replacing sizing cream in order to prevent blockage of paste delivery tube.The influences o...The usability of polyoxyethylene stearate with 10 ethylene epoxides(POES 10) as lubricant in warp sizing was investigated for replacing sizing cream in order to prevent blockage of paste delivery tube.The influences of POES 10 and sizing cream upon the adhesion of starch to fibers and the performances of starch film were measured and compared.Then,the usability of POES 10 as lubricant was evaluated through the comparison between POES 10 and sizing cream in tensile behaviors,abrasion resistance,and hairiness of sized cotton yarns.The experimental observation demonstrates that the influence of POES 10 upon the adhesion is similar to that of sizing cream.POES 10 is superior to sizing cream in tensile strength and breaking elongation of starch film when mass content of lubricants is equal to or exceeds 2%.Incorporating POES 10 into starch makes starch film more resistant to wear.Furthermore,POES 10 is preferred to sizing cream in the increase in tensile strength,loss in elongation,and abrasion resistance of sized cotton yarns.Using POES 10 as lubricant in size formulation is favorable to the decrease of longer hairs on sized yarns.POES 10 exhibits potential use during cotton warp sizing for replacing sizing cream.展开更多
In this article, 12-acryloyloxystearic acid was synthesized, which was then used to prepare the magnesium 12-acryloyloxy stearate detergent. Reaction conditions for synthesizing 12-acryloyloxystearic acid, including t...In this article, 12-acryloyloxystearic acid was synthesized, which was then used to prepare the magnesium 12-acryloyloxy stearate detergent. Reaction conditions for synthesizing 12-acryloyloxystearic acid, including the molar ratio of 12-hydroxystearic acid to acrylic acid, the catalyst amount, the esterification temperature, and the esterification time, were optimized. Under the optimized conditions, the 12-acryloyloxystearic acid with an acid value of 159 mg KOH/g and a melting range of between 70.4 ℃ and 71.4 ℃ was obtained. The structure of 12-acryloyloxystearic acid was confirmed by FTIR spectroscopy. Results of preparing magnesium 12-acryloyloxy stearate detergent showed the existence of acryloyloxy radical in 12-hydroxystearic acid could improve the quality of lubricant detergent greatly.展开更多
Introduction: The rise in antibiotic resistant cases has caused a global concern. Researchers around the world are trying to find a novel alternative to combat this issue. Green tea with its many health benefits, incl...Introduction: The rise in antibiotic resistant cases has caused a global concern. Researchers around the world are trying to find a novel alternative to combat this issue. Green tea with its many health benefits, including antibacterial and antiviral activity, has shown to be one of the most promising candidates to be used as an agent to solve this problem. Objective: This study focuses on evaluating the synergistic effects of antibiotics and two green tea polyphenols: epigallocatechin gallate (EGCG), and its modified lipophilic form epigallocatechin gallate stearate (EGCG-S). Methods: In this study, twelve antibiotics and eight bacteria: Gram-positive Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis) and Bacillus megaterium (B. megaterium);Gram-negative Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Serratia marcescens (S. marcescens), and Enterobacter aerogenes (E. aerogenes);and acid-fast Mycobacterium smegmatis (M. smegmatis) were used. Antibacterial synergism profiling of EGCG, EGCG-S and antibiotics has been established using a disk diffusion assay. Results: The results revealed that both 1% of EGCG and 1% EGCG-S enhanced the antimicrobial activities on antibiotics in various bacteria. Antimicrobial susceptibility study indicated that EGCG-S was able to enhance some antibiotics from the resistant category to intermediate or susceptible and/or from intermediate category to susceptible. Both EGCG and EGCG-S worked comparably on Gram-positive bacteria;in S. aureus, both compounds enhanced 5 antibiotics (AM10, CF30, C30, S10 and TE30) activities while EGCG-S had higher efficiency. B. megaterium were susceptible to most of the antibiotic treatment, thus the impact of EGCG and EGCG-S was insignificant. EGCG-S worked better than EGCG on Gram-negative bacteria;converted 9 antibiotics susceptibility in E. coli and P. aeruginosa, and 8 antibiotics in E. aerogenes. EGCG and EGCG-S also showed synergism on acid-fast bacteria M. smegmatis with EGCG-S has much higher efficiency than EGCG. Conclusion: The results suggested that EGCG-S might be a promising antibacterial synergistic agent with antibiotics to combat antibiotic-resistant bacteria.展开更多
文摘A series of stearates with different rare-earth ion were investigated as thermal stabilizers for rigid PVC at 180 ℃ in air. Their stabilizing efficiency was based on measuring the rate of dehydrochlorination. The resulted revealed the higher stabilizing efficiency of the investigated rare-earth stearates as thermal stabilizers for rigid PVC compared with the thermal stabilizers for industry: calcium stearate, zinc stearate, butyl stannum mercaptide, phosphite esters, β-diketone and epoxidized sunflower oil. This was well illustrated by longer incubation period (T_S) values and lower rate of dehydrochlorination. The stable efficiency was affected by the nature of rare-earth element's individual electronic shell. The mechanism for the stabilizing effect of rare-earth stearates was proposed. The result was experimentally proved based on IR spectrum.
文摘Waste shell stacking with odor and toxicity is a serious hazard to our living environment. To make effective use of the natural resources, the shell powder was applied as a filler of outdoor thermal insulation coatings. Sodium stearate(SS) was used to modify the properties of shell powder to reduce its agglomeration and to increase its compatibility with the emulsion. The oil absorption rate and the spectrum reflectance of the shell powder show that the optimized content of SS as a modifier is 1.5wt%. The total spectrum reflectance of the coating made with the shell powder that is modified at this optimum SS content is 9.33% higher than that without any modification. At the optimum SS content of 1.5wt%, the thermal insulation of the coatings is improved by 1.0℃ for the cement mortar board and 1.6℃ for the steel plate, respectively. The scouring resistance of the coating with the 1.5wt% SS-modified shell powder is three times that of the coating without modification.
基金supported by the International Corporation Project (Grant No.07SU07001)the Science Foundation of Science and Technology Commission of Shanghai Municipality (Grant No.0552nm011)
文摘In this study, the barite nanoparticles were successfully modified with stearate and the influence of stearate addition on the performance of barite nanoparticles was systematically investigated. The products were characterized by activating factor analysis, contact angle test, surface energy calculation, sedimentation rate calculation, rheological measurement, and FT-IR analysis, etc. As the quantity of added stearate increased, both the activating factor and contact angle of barite nanoparticles increased first then decreased. When the stearate content was 5% of the mass of barite nanoparticles, the activating factor and water contact angle of modified particles reached maximum value, 97% and 126% respectively. At this time, the sedimentation rate reached minimum, and so did the surface energy. The rheological test reveals that the viscosity of modified barite nanoparticles/petronol system decreases greatly, indicating the surface performance of barite nanoparticles has changed from hydrophilicity to lipophilicity after modification. C=O and COO stretching vibration peaks were found in the FT-IR spectra, which proves that the stearate has combined onto the surface of barite nanoparticles. Finally, according to the zeta potential result of unmodified barite, the possible modification mechanism was provided.
文摘Epigallocatechin gallate (EGCG), a green tea polyphenol possesses antioxidant, antibacterial, anticancer and antiviral properties. EGCG-Stearate (EGCG-S) is of interest for this study because of its stability and lipophilic properties. The chemical modification of EGCG-S increased its lipid solubility. Herpes simplex virus-1 (HSV-1), a member of the family Herpesviridae, and Alphaherpesvirinae subfamily is a leading cause of human viral diseases in the United States. In this study, 25 μM, 50 μM, 75 μM, and 100 μM of EGCG and EGCG-S were used to carry out cytotoxicity, cell viability and cell proliferation assays to determine the maximum non-cytotoxic concentrations on cultured A549 cells. The results suggested that 75 μM of EGCG and EGCG-S is the appropriate concentration to further study the effect on the infection of HSV-1 in A549 cells. Infectivity, antiviral, and inverted microscopy assays were performed to study the effects of EGCG and EGCG-S on HSV-1 infection. An antiviral assay was performed using luminescence and it indicated that EGCG-S treated HSV-1 showed up to 90% inhibition. Confocal microscopy images further supported the inhibitory effects of 75 μM EGCG-S on HSV-1 infection in A549 cells. The long-term goal of this research is to use EGCG-S as a possible novel topical therapeutic treatment to limit the spread of HSV-1 infections.
基金Supported by the International Foundation for Science(IFS)the Organization for the Prohibition of Chemical Weapons(OPCW)for the Research Grant(IFS Research Grant F/4921-2)
文摘Objective:To perform phytochemical analyses on the leaves of Ocimum basilicum L.(O.basilicum),to elucidate the structure of isolate and then perform the antisickling activity on the crude extract and on the isolate.Methods:The Emmel test performed on the acidified methanolic extract of this plant was used to evaluate the antisickling activity.The structure characterization of the active compound was performed using chromatographic techniques for the separation and the spectroscopic ones for structure elucidation(1H-NMR,13C-NMR.COSY,HMBC).Resurte:The chemical screening on the crude extract revealed the presence of polyphenols(flavonoids,anthocyanins,leucoanthocyanins,tannins,quinones) alkaloids,saponins,triterpenoids and steroids.The ohtained extract after evaporation yielded 34.50g(11.5%) out of 300g of powdered leaves of O.basilicum.The acidified methanolic extract and butyl stearate showed an interesting antisickling activity.Conchisions:The acidified methanolic extract and butyl stearate from O.basilicum displayed a good antisickling activity.To the best of our knowledge,this is the first time to report the antisickling activity of this compound in this plant.The synmesized compound presented the same spectroscopic characteristics than the natural one and the antisickling activities of its derivatives are understudying.
基金funded by the Fundamental Research Funds for the Central Universities(No.2572017CB24)the Postdoctoral Scientific Research Starting Foundation of Heilongjiang Province(No.LBH-Q17004)
文摘Glycerol stearate was synthesized by esterification with non-toxic,inexpensive glycerol and stearic acid.The composite of glycerol stearate and Pinus radiata wood was prepared by vacuum impregnation.By Fourier transform infrared(FTIR)analysis,there was the generation of new C=O stretching vibration band of glycerol stearate in comparison with stearic acid.This confirms that glycerol stearate was successfully synthesized.The weight gain,FTIR spectrum and morphological analyses of the composite indicate that glycerol stearate was impregnated into the interior lumina of the cells.Thermal analysis showed that the maximal degradation temperature of the composite was 42℃higher than untreated wood.Contact angle images indicated that the value of the composite was134.2°.Hydrophobicity(the repulsion of water)of the composite was stronger than glycerol stearate,which a large number of hydroxyl of wood reacted with the oxygen-containing groups of glycerol stearate,improved hydrophobicity and thermal stability,thereby enhancing the potential application of P.radiata wood.
基金Project(50572045) supported by the National Natural Science Foundation of Chinaproject supported by Innovation Fund from the PetroChina Company Limited
文摘For thermal energy storage application in energy-saving building materials,silica microcapsules containing phase change material were prepared using sol-gel method in O/W emulsion system. In the system droplets in microns are formed by emulsifying an organic phase consisting of butyl-stearate as core material. The silica shell was formed via hydrolysis and condensation from tetraethyl silicate with acetate as catalyst. The SEM photographs show the particles possess spherical morphology and core-shell structure. The as-prepared silica microcapsules mainly consist of microsphere in the diameter of 3-7 μm and the median diameter of these microcapsules equals to 5.2 μm. The differential scanning calorimetry(DSC) curves indicate that the latent heat and the melting point of microcapsules are 86 J/g and 22.6 ℃,respectively. The results of DSC and TG further testify the microcapsules with core-shell structure.
基金Research Foundation Program of Scientific and Technological Innovation Team of College and University at the Provincial Level of Anhui,China (No.TD200710)
文摘The usability of polyoxyethylene stearate with 10 ethylene epoxides(POES 10) as lubricant in warp sizing was investigated for replacing sizing cream in order to prevent blockage of paste delivery tube.The influences of POES 10 and sizing cream upon the adhesion of starch to fibers and the performances of starch film were measured and compared.Then,the usability of POES 10 as lubricant was evaluated through the comparison between POES 10 and sizing cream in tensile behaviors,abrasion resistance,and hairiness of sized cotton yarns.The experimental observation demonstrates that the influence of POES 10 upon the adhesion is similar to that of sizing cream.POES 10 is superior to sizing cream in tensile strength and breaking elongation of starch film when mass content of lubricants is equal to or exceeds 2%.Incorporating POES 10 into starch makes starch film more resistant to wear.Furthermore,POES 10 is preferred to sizing cream in the increase in tensile strength,loss in elongation,and abrasion resistance of sized cotton yarns.Using POES 10 as lubricant in size formulation is favorable to the decrease of longer hairs on sized yarns.POES 10 exhibits potential use during cotton warp sizing for replacing sizing cream.
基金This work was supported by the National Undergraduate Innovative Training Program(201410375004)the Scientific Research Foundation for Introduced Scholars,Huangshan University(2015xkjq002)the Scientific Research Foundation of Huangshan University(2014xkj012)
文摘In this article, 12-acryloyloxystearic acid was synthesized, which was then used to prepare the magnesium 12-acryloyloxy stearate detergent. Reaction conditions for synthesizing 12-acryloyloxystearic acid, including the molar ratio of 12-hydroxystearic acid to acrylic acid, the catalyst amount, the esterification temperature, and the esterification time, were optimized. Under the optimized conditions, the 12-acryloyloxystearic acid with an acid value of 159 mg KOH/g and a melting range of between 70.4 ℃ and 71.4 ℃ was obtained. The structure of 12-acryloyloxystearic acid was confirmed by FTIR spectroscopy. Results of preparing magnesium 12-acryloyloxy stearate detergent showed the existence of acryloyloxy radical in 12-hydroxystearic acid could improve the quality of lubricant detergent greatly.
文摘Introduction: The rise in antibiotic resistant cases has caused a global concern. Researchers around the world are trying to find a novel alternative to combat this issue. Green tea with its many health benefits, including antibacterial and antiviral activity, has shown to be one of the most promising candidates to be used as an agent to solve this problem. Objective: This study focuses on evaluating the synergistic effects of antibiotics and two green tea polyphenols: epigallocatechin gallate (EGCG), and its modified lipophilic form epigallocatechin gallate stearate (EGCG-S). Methods: In this study, twelve antibiotics and eight bacteria: Gram-positive Staphylococcus aureus (S. aureus), Staphylococcus epidermidis (S. epidermidis) and Bacillus megaterium (B. megaterium);Gram-negative Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Serratia marcescens (S. marcescens), and Enterobacter aerogenes (E. aerogenes);and acid-fast Mycobacterium smegmatis (M. smegmatis) were used. Antibacterial synergism profiling of EGCG, EGCG-S and antibiotics has been established using a disk diffusion assay. Results: The results revealed that both 1% of EGCG and 1% EGCG-S enhanced the antimicrobial activities on antibiotics in various bacteria. Antimicrobial susceptibility study indicated that EGCG-S was able to enhance some antibiotics from the resistant category to intermediate or susceptible and/or from intermediate category to susceptible. Both EGCG and EGCG-S worked comparably on Gram-positive bacteria;in S. aureus, both compounds enhanced 5 antibiotics (AM10, CF30, C30, S10 and TE30) activities while EGCG-S had higher efficiency. B. megaterium were susceptible to most of the antibiotic treatment, thus the impact of EGCG and EGCG-S was insignificant. EGCG-S worked better than EGCG on Gram-negative bacteria;converted 9 antibiotics susceptibility in E. coli and P. aeruginosa, and 8 antibiotics in E. aerogenes. EGCG and EGCG-S also showed synergism on acid-fast bacteria M. smegmatis with EGCG-S has much higher efficiency than EGCG. Conclusion: The results suggested that EGCG-S might be a promising antibacterial synergistic agent with antibiotics to combat antibiotic-resistant bacteria.
