Silicic acid,commonly derived from cheap and easily available sodium silicate,has recently received great attention for application in leather industry to produce ecological leather with a cleaner approach.However,lea...Silicic acid,commonly derived from cheap and easily available sodium silicate,has recently received great attention for application in leather industry to produce ecological leather with a cleaner approach.However,leather tanned with silicic acid alone is poor in storage stability,which limits its practical application in leather production.In this work,a new environment-friendly combination tannage based on silicic acid and plant tannin was developed to address this issue along with improving the comprehensive performances of leather.The obtained leather was characterized by scanning electron microscopy,Fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy and so on.The results showed that compared with leather tanned with silicic acid alone,the leather tanned with this combination method possessed improved thermal stability,enhanced mechanical properties,acceptable softness,appropriate hydrophilicity,and especially enhanced storage stability.More importantly,the combination tanned leather with 1:1 of the mass ratio of silicic acid to vegetable tannin(composed of valonea extract and mimosa extract with the same weight)had more prominent comprehensive performances.In addition,the results demonstrated that hydrogen bonding played an important role in the combination tanning process.Furthermore,the hydrogen bonds generated between phenolic hydroxyl groups of polyphenols with silicon hydroxyl groups of silicic acid molecules inhibited the excessive condensation of Si-OH groups between themselves.Subsequently,the assessment of environmental impact revealed the value of BOD 5/COD of the wastewater produced in this combination tanning process is more than 0.3,indicating the chrome-free combination tannage based on silicic acid and plant tannin was an environment-friendly tanning technology.These findings therefore indicated that a new chrome-free tanning method with silicon and biomass materials as main tanning agents has potential practical application prospect in leather production.展开更多
The utilization of ethnobotanical and phytochemical investigations in the discovery of novel medications is beneficial. Screening for phytochemicals is an important step in detecting the bioactive ingredients of medic...The utilization of ethnobotanical and phytochemical investigations in the discovery of novel medications is beneficial. Screening for phytochemicals is an important step in detecting the bioactive ingredients of medicinal plants which are used in conventional therapy. For the first time, 23 medicinal plants utilized in Saudi Arabian traditional therapy were examined. From August 2020 to July 2021, ethnobotanical fieldwork was conducted. There was some plant species identified, divided into pertinent families. Standard procedures were used to screen these medicinal plants for the occurrence of glycosides, alkaloids, saponins, resins, saponins, tannins, and flavonoids. Among the medicinal plants used, the most common phytochemicals were alkaloids (95.65%), glycosides (86.96%), saponin (82.61%), tannins (73.91%), flavonoids (56.52%), and resin (52.17%). The least widely distributed chemicals, on the other side, were resins. Trigonella foenum-graecum L., Pimpinella anisum L., and Cuminum cyminum L. seeds were shown to contain all six categories of secondary metabolites. The ethnographic importance of these medicinal plants is consistent with the content of secondary metabolites.展开更多
In this paper, a new kind of adsorption resin with multi-phenolic hydroxyl was created by immobilizing black wattle bark tannins to chloromethyl polystyrene resin. Its adsorption capacity to cation dye was tested. Wit...In this paper, a new kind of adsorption resin with multi-phenolic hydroxyl was created by immobilizing black wattle bark tannins to chloromethyl polystyrene resin. Its adsorption capacity to cation dye was tested. With an orthogonal test the optimal conditions of synthesis were determined： the concentration of sodium hydroxide solution 1.0 mol.L^-1; the reaction time is one hour and the mass concentration of tannins 5%. With single factorial experiment the optimal conditions of adsorption were confirmed： a solidified pH of 5.0; an adsorption temperature of 25℃ and a cation dye concentration of 100 mg.L^-1. The adsorption for cation dye can be similar to Langmuir isotherms.展开更多
基金This research was supported by the National Natural Science Foundation of China(No.21376153)the Fundamental Research Funds for the Central University of China,and Sichuan University-Zschimmer&Schwarz CmbH&Co.KG Scholarships(2020).
文摘Silicic acid,commonly derived from cheap and easily available sodium silicate,has recently received great attention for application in leather industry to produce ecological leather with a cleaner approach.However,leather tanned with silicic acid alone is poor in storage stability,which limits its practical application in leather production.In this work,a new environment-friendly combination tannage based on silicic acid and plant tannin was developed to address this issue along with improving the comprehensive performances of leather.The obtained leather was characterized by scanning electron microscopy,Fourier transform infrared spectroscopy,X-ray photoelectron spectroscopy and so on.The results showed that compared with leather tanned with silicic acid alone,the leather tanned with this combination method possessed improved thermal stability,enhanced mechanical properties,acceptable softness,appropriate hydrophilicity,and especially enhanced storage stability.More importantly,the combination tanned leather with 1:1 of the mass ratio of silicic acid to vegetable tannin(composed of valonea extract and mimosa extract with the same weight)had more prominent comprehensive performances.In addition,the results demonstrated that hydrogen bonding played an important role in the combination tanning process.Furthermore,the hydrogen bonds generated between phenolic hydroxyl groups of polyphenols with silicon hydroxyl groups of silicic acid molecules inhibited the excessive condensation of Si-OH groups between themselves.Subsequently,the assessment of environmental impact revealed the value of BOD 5/COD of the wastewater produced in this combination tanning process is more than 0.3,indicating the chrome-free combination tannage based on silicic acid and plant tannin was an environment-friendly tanning technology.These findings therefore indicated that a new chrome-free tanning method with silicon and biomass materials as main tanning agents has potential practical application prospect in leather production.
文摘The utilization of ethnobotanical and phytochemical investigations in the discovery of novel medications is beneficial. Screening for phytochemicals is an important step in detecting the bioactive ingredients of medicinal plants which are used in conventional therapy. For the first time, 23 medicinal plants utilized in Saudi Arabian traditional therapy were examined. From August 2020 to July 2021, ethnobotanical fieldwork was conducted. There was some plant species identified, divided into pertinent families. Standard procedures were used to screen these medicinal plants for the occurrence of glycosides, alkaloids, saponins, resins, saponins, tannins, and flavonoids. Among the medicinal plants used, the most common phytochemicals were alkaloids (95.65%), glycosides (86.96%), saponin (82.61%), tannins (73.91%), flavonoids (56.52%), and resin (52.17%). The least widely distributed chemicals, on the other side, were resins. Trigonella foenum-graecum L., Pimpinella anisum L., and Cuminum cyminum L. seeds were shown to contain all six categories of secondary metabolites. The ethnographic importance of these medicinal plants is consistent with the content of secondary metabolites.
文摘In this paper, a new kind of adsorption resin with multi-phenolic hydroxyl was created by immobilizing black wattle bark tannins to chloromethyl polystyrene resin. Its adsorption capacity to cation dye was tested. With an orthogonal test the optimal conditions of synthesis were determined： the concentration of sodium hydroxide solution 1.0 mol.L^-1; the reaction time is one hour and the mass concentration of tannins 5%. With single factorial experiment the optimal conditions of adsorption were confirmed： a solidified pH of 5.0; an adsorption temperature of 25℃ and a cation dye concentration of 100 mg.L^-1. The adsorption for cation dye can be similar to Langmuir isotherms.
