TaN coatings were deposited on Ti bipolar plates by magnetron sputtering to improve corrosion resistance and service life.The influence of N_(2) flow rate on the surface morphology,hydrophobicity,crystallinity,corrosi...TaN coatings were deposited on Ti bipolar plates by magnetron sputtering to improve corrosion resistance and service life.The influence of N_(2) flow rate on the surface morphology,hydrophobicity,crystallinity,corrosion resistance,and interfacial contact resistance of TaN coatings was studied.Results show that as the N_(2) flow rate increases,the roughness of TaN coatings decreases firstly and then increases,and the hydrophobicity increases firstly and then decreases.At the N_(2) flow rate of 3 mL/min,TaN coating with larger grain size presents lower roughness and high hydrophobicity.The coating possesses the lowest corrosion current density of 2.82µA·cm^(−2) and the highest corrosion potential of−0.184 V vs.SCE in the simulated proton exchange membrane water electrolyser environment.After a potentiostatic polarization test for 10 h,a few corrosion pits are observed on the TaN coatings deposited at an N_(2) flow rate of 3 mL/min.After 75 h of electrolytic water performance testing,the TaN coating on bipolar plate improves the corrosion resistance and thus enhances the electrolysis efficiency(68.87%),greatly reducing the cost of bipolar plates.展开更多
Traditional chrome tanning technology is still widely used today. In this technology, chrome shaving as well as chrome contained effluent in tanning and retanning processes is a big issue in the industry. Wet white ta...Traditional chrome tanning technology is still widely used today. In this technology, chrome shaving as well as chrome contained effluent in tanning and retanning processes is a big issue in the industry. Wet white tanning technology has been gaining in importance in recent years, but in general, the comprehensive performance of chrome-free tanned leather is not comparable with that of chrome tanned leather. In the present work, chrome-free tanning and chrome tanning are combined in a reversed procedure, which produces leather with chrome tanned leather quality without chrome tanned leather waste problems. In this procedure, a special amphoteric organic compound, no pickle, no salt chrome-free tanning agent TWT was used to tan delimed hides （no pickle） making wet white with shrinking temperature at 80-85 ~C. Then, new method called reversed tanning further process the wet white into chrome-tanned crust. In this reversed method, retanning, fatliquoring and coloring processes were carried out before chrome tanning. This technology eliminates chrome waste issue in tanning, shaving, post tanning processes. The chrome contained effluent is only concentrated in the last chrome tanning process. The leather made with this technology has complete conventional chrome-tanned leather quality. In this way, chrome leather quality without chrome waste problems was achieved. So, it is a new clean tanning technology.展开更多
While walking in Xiamen University,you can enjoy the gentle ocean breezes,the blue sky and the exquisite Tan Kah-Kee-style architecture.It has architectural styles from both the East and the West.To have a deeper unde...While walking in Xiamen University,you can enjoy the gentle ocean breezes,the blue sky and the exquisite Tan Kah-Kee-style architecture.It has architectural styles from both the East and the West.To have a deeper understanding of the design,I’ll introduce a prominent community leader and philanthropist(慈善家),Tan Kah Kee(or Chen Jiageng)who was also a founder of Xiamen University and Jimei University to you.展开更多
Collagen powder hydrolysates were reacted with a solution of commercial mimosa bark tannin extract.The mixture was prepared at ambient temperature and prepared at 80°C to determine what reactions,if any,did occur...Collagen powder hydrolysates were reacted with a solution of commercial mimosa bark tannin extract.The mixture was prepared at ambient temperature and prepared at 80°C to determine what reactions,if any,did occur between the collagen protein through its amino acids and the polyphenolic condensed tannin.The reaction products obtained were analyzed by matrix assisted laser desorption ionization time-of-flight(MALDI ToF)mass spectrometry.Reactions between the two materials did appear to occur,with the formation of a relatively small proportion of covalent and ionic linkages at ambient temperature but a considerable proportion of covalent linkages tannin-protein amino acids and the disappearance of ionic bonds.The linkages between the two materials appeared to be by amination of the phenolic–OHs of the tannin by the amino groups of the non-skeletal side chains of arginine,and by esterification by the–COOH groups of glutamic and aspartic acid of the aliphatic alcohol-OH on the C3 site of the flavonoid units heterocycle of the tannin.The proportion of covalent linkages increases markedly and predominate with increasing temperatures.This tightening of the tannin-protein covalent network formed may be an additional contributing factor both to leather wear resistance and performance as well to leather shrinking when this is subjected to excessive temperatures.展开更多
The acid-base properties of 1-（2-thiazolylazo）-2-naphthol （TAN） in mixtures of methanol-water at 25℃ and an ionic strength of 0.1 mol/L are studied by a multi-wavelength spectrophotometfic method. The acidity con...The acid-base properties of 1-（2-thiazolylazo）-2-naphthol （TAN） in mixtures of methanol-water at 25℃ and an ionic strength of 0.1 mol/L are studied by a multi-wavelength spectrophotometfic method. The acidity constants of all related equilibria are estimated using the whole spectral fitting of the collected data to an established factor analysis model. DATAN program was used for determination of acidity constants. The corresponding pKa values in methanol-water mixtures were determined. There is a linear relationship between acidity constants and the mole fraction of methanol in the solvent mixtures.展开更多
基金National Key Research and Development Program of China(2022YFB4002100)National Natural Science Foundation of China(52271136)Natural Science Foundation of Shaanxi Province(2021JC-06)。
文摘TaN coatings were deposited on Ti bipolar plates by magnetron sputtering to improve corrosion resistance and service life.The influence of N_(2) flow rate on the surface morphology,hydrophobicity,crystallinity,corrosion resistance,and interfacial contact resistance of TaN coatings was studied.Results show that as the N_(2) flow rate increases,the roughness of TaN coatings decreases firstly and then increases,and the hydrophobicity increases firstly and then decreases.At the N_(2) flow rate of 3 mL/min,TaN coating with larger grain size presents lower roughness and high hydrophobicity.The coating possesses the lowest corrosion current density of 2.82µA·cm^(−2) and the highest corrosion potential of−0.184 V vs.SCE in the simulated proton exchange membrane water electrolyser environment.After a potentiostatic polarization test for 10 h,a few corrosion pits are observed on the TaN coatings deposited at an N_(2) flow rate of 3 mL/min.After 75 h of electrolytic water performance testing,the TaN coating on bipolar plate improves the corrosion resistance and thus enhances the electrolysis efficiency(68.87%),greatly reducing the cost of bipolar plates.
文摘Traditional chrome tanning technology is still widely used today. In this technology, chrome shaving as well as chrome contained effluent in tanning and retanning processes is a big issue in the industry. Wet white tanning technology has been gaining in importance in recent years, but in general, the comprehensive performance of chrome-free tanned leather is not comparable with that of chrome tanned leather. In the present work, chrome-free tanning and chrome tanning are combined in a reversed procedure, which produces leather with chrome tanned leather quality without chrome tanned leather waste problems. In this procedure, a special amphoteric organic compound, no pickle, no salt chrome-free tanning agent TWT was used to tan delimed hides （no pickle） making wet white with shrinking temperature at 80-85 ~C. Then, new method called reversed tanning further process the wet white into chrome-tanned crust. In this reversed method, retanning, fatliquoring and coloring processes were carried out before chrome tanning. This technology eliminates chrome waste issue in tanning, shaving, post tanning processes. The chrome contained effluent is only concentrated in the last chrome tanning process. The leather made with this technology has complete conventional chrome-tanned leather quality. In this way, chrome leather quality without chrome waste problems was achieved. So, it is a new clean tanning technology.
文摘While walking in Xiamen University,you can enjoy the gentle ocean breezes,the blue sky and the exquisite Tan Kah-Kee-style architecture.It has architectural styles from both the East and the West.To have a deeper understanding of the design,I’ll introduce a prominent community leader and philanthropist(慈善家),Tan Kah Kee(or Chen Jiageng)who was also a founder of Xiamen University and Jimei University to you.
文摘Collagen powder hydrolysates were reacted with a solution of commercial mimosa bark tannin extract.The mixture was prepared at ambient temperature and prepared at 80°C to determine what reactions,if any,did occur between the collagen protein through its amino acids and the polyphenolic condensed tannin.The reaction products obtained were analyzed by matrix assisted laser desorption ionization time-of-flight(MALDI ToF)mass spectrometry.Reactions between the two materials did appear to occur,with the formation of a relatively small proportion of covalent and ionic linkages at ambient temperature but a considerable proportion of covalent linkages tannin-protein amino acids and the disappearance of ionic bonds.The linkages between the two materials appeared to be by amination of the phenolic–OHs of the tannin by the amino groups of the non-skeletal side chains of arginine,and by esterification by the–COOH groups of glutamic and aspartic acid of the aliphatic alcohol-OH on the C3 site of the flavonoid units heterocycle of the tannin.The proportion of covalent linkages increases markedly and predominate with increasing temperatures.This tightening of the tannin-protein covalent network formed may be an additional contributing factor both to leather wear resistance and performance as well to leather shrinking when this is subjected to excessive temperatures.
文摘The acid-base properties of 1-（2-thiazolylazo）-2-naphthol （TAN） in mixtures of methanol-water at 25℃ and an ionic strength of 0.1 mol/L are studied by a multi-wavelength spectrophotometfic method. The acidity constants of all related equilibria are estimated using the whole spectral fitting of the collected data to an established factor analysis model. DATAN program was used for determination of acidity constants. The corresponding pKa values in methanol-water mixtures were determined. There is a linear relationship between acidity constants and the mole fraction of methanol in the solvent mixtures.
