Aerogels are predominantly mesoporous,extremely lightweight,low density(∼0.003 g/cm 3)and thermally insulat-ing materials.Over the years,aerogels have gained increasing attention due to their extraordinary properties...Aerogels are predominantly mesoporous,extremely lightweight,low density(∼0.003 g/cm 3)and thermally insulat-ing materials.Over the years,aerogels have gained increasing attention due to their extraordinary properties(light,heat,sound,electricity and force)and application potentials in varieties of fields.Several studies have been carried out regarding aerogel preparation and its applications in coatings on different substrates.In this review,an overview of aerogels preparation and their application progress in coatings of most common substrates is presented.Attention is paid to aerogel coatings of textiles,leather,and substrates other than leather and textiles for special functionali-ties that could address the application progress in coatings.This review will help to inspire scientists and engineers towards novel aerogel materials and technologies to boost the industrial fabrication of flexible advanced materials.展开更多
The application and mechanism study of microwave irradiation in traditional industries have attracted considerable attention owing to the unique thermal and athermal effects that could lead to unexpected benefits in h...The application and mechanism study of microwave irradiation in traditional industries have attracted considerable attention owing to the unique thermal and athermal effects that could lead to unexpected benefits in high-efficiency and clean production.Herein,we report the investigation of the aluminum tanning under microwave irradiation upon using hide powder and skin pieces,respectively,as simulants of real hide or skin.The aluminum tanning process and the tanned products under microwave heating(MWH)were studied and compared with those of conventional water bath heating(WBH)as the controls.For the tanning system of hide powder,the tanning effluents were analyzed in terms of pH,conductivity,dielectric constant and aluminum content,and the tanned powder was investigated by differential scanning calorimetry(DSC),thermogravimetric(TG)analysis,and FT-IR spectroscopy.For the skin piece system,the pH and aluminum content of tanning effluents were also determined,and at the same time,DSC,TG,SEM,FT-IR and shrinkage temperature were used to illustrate the actions of microwaves on the structure and properties of the tanned pieces.The results show that aluminum reactivity in the penetration and binding process of collagen fibers in hide powder and skin pieces improved using microwave treatment.The residual aluminum content was greatly reduced by microwave heating action,and the increased amount of aluminum with evener distribution was observed in the tanned products.Microwave irradiation also resulted in the tanned products with better thermal stability and thermal decomposition resistance.This work further promotes application of microwave treatments for aluminumbased tanning in leather industry.展开更多
The global demand for renewable and affordable feed-stocks,combined with the worldwide targets for reduc-ing carbon emissions,is the driving force behind a breakthrough in resource revolution and GreenTech innovations...The global demand for renewable and affordable feed-stocks,combined with the worldwide targets for reduc-ing carbon emissions,is the driving force behind a breakthrough in resource revolution and GreenTech innovations[1].Owing to the vast reserves and short growing cycle,utilizing lignocellulosic biomass as an alternative to petroleum and environmentally friendly feedstock to furnish bioenergy and biomaterials is key to building a more sustainable future.Lignocellulose mainly contains three biopolymers,i.e.,cellulose,hemicellulose and lignin.Over the centuries,utilization of lignocellu-lose has crossed its possible molecular scale ranging from 101 m,as the original matrix,to 10-10 m,as a mono-meric molecule.展开更多
Dialdehyde sodium alginate(DSA)is an alternative chrome-free tanning material for fur production.To obtain satisfactory resultant fur and provide suggestions for the usage of DSA in fur making,the general properties o...Dialdehyde sodium alginate(DSA)is an alternative chrome-free tanning material for fur production.To obtain satisfactory resultant fur and provide suggestions for the usage of DSA in fur making,the general properties of DSA tanned sheep fur were systematically investigated.The tanning mechanism of DSA was analyzed and it was verified that DSA was mainly combined with collagen fiber by forming Schiff base covalent bonds while supplemented by a small number of hydrogen bonds and ionic bonds.Due to the acid sensitivity of Schiff base structure,DSA tanned fur had poor resistance to acid rinsing but had excellent resistance to washing and good fatliquoring performance.Also,it had good resistances to yellowing and reductant.After being retanned by chrome tanning agent,the fur was capable of enduring a high-temperature dyeing process(68°C for 8 h).Overall,DSA tanned sheep fur had favorable properties under appropriate post-tanning processing conditions to manufacture light-colored or dark-colored fur products with desirable physical properties.展开更多
Since microwave irradiation could promote hydrolysis and olation of chromium tanning liquor,but the influence of microwave on chromium complex component in the liquor was still unknown.Chromium sulphate solution(0%bas...Since microwave irradiation could promote hydrolysis and olation of chromium tanning liquor,but the influence of microwave on chromium complex component in the liquor was still unknown.Chromium sulphate solution(0%basicity)and 33%basicity chromium tanning liquor were subjected microwave(MW)and water bath(WB)heating,and the samples without any warming were regarded as control.Ion exchange chromatography(IEC)and gel filtration chromatography(GFC)were used to measure the charge composition and molecular size of chromium complexes in each sample.FT-IR was used to characterize the structure of chromium complexes in each composition separated by IEC.Moreover,the chromium tanning liquor after warming was used in hide powder tanning trials to illustrate whether microwave would affect its tanning ability.The results show there are more high positive charge and large molecular size complexes in chromium tanning liquor after warming but the phenomena are more significant in MW samples compared with WB due to non-thermal effect of microwave.In addition,microwave has more powerful effect on 33%basicity chromium tanning liquor hydrolysis and olation to generate larger molecular size complexes.In FT-IR results,the combination pattern between chromium and ligands are changed after warming but there is no difference between WB and MW.The chromium exhaustion and thermal stability of hide powder tanned with chromium tanning liquor after microwave irradiation are both higher.It could conclude that both thermal and non-thermal effects of microwave promote the process together,and the nonthermal effect leads to more high positive charge and large molecular size complexes and has stronger influence on high polarity system.In short,this work would provide theoretical basis for applying microwave in tanning agent modification and chrome tanning process further.展开更多
基金This work was financially supported by the National Foreign Experts Program-Foreign Youth Talent Program(QN20200173001)the National Key R&D Pro-gram(2020YFE0203800)the Research and development project of China Leather and Footwear Research Institute Co.Ltd.(2021PGX02).
文摘Aerogels are predominantly mesoporous,extremely lightweight,low density(∼0.003 g/cm 3)and thermally insulat-ing materials.Over the years,aerogels have gained increasing attention due to their extraordinary properties(light,heat,sound,electricity and force)and application potentials in varieties of fields.Several studies have been carried out regarding aerogel preparation and its applications in coatings on different substrates.In this review,an overview of aerogels preparation and their application progress in coatings of most common substrates is presented.Attention is paid to aerogel coatings of textiles,leather,and substrates other than leather and textiles for special functionali-ties that could address the application progress in coatings.This review will help to inspire scientists and engineers towards novel aerogel materials and technologies to boost the industrial fabrication of flexible advanced materials.
基金Financial support from the National Natural Science Foundation(No.21576171)the Science&Technology Department of Sichuan Province(No.2018HH0038)is gratefully acknowledgedfunded by the Innovation Training Program for college students of Sichuan University(C2020107809).
文摘The application and mechanism study of microwave irradiation in traditional industries have attracted considerable attention owing to the unique thermal and athermal effects that could lead to unexpected benefits in high-efficiency and clean production.Herein,we report the investigation of the aluminum tanning under microwave irradiation upon using hide powder and skin pieces,respectively,as simulants of real hide or skin.The aluminum tanning process and the tanned products under microwave heating(MWH)were studied and compared with those of conventional water bath heating(WBH)as the controls.For the tanning system of hide powder,the tanning effluents were analyzed in terms of pH,conductivity,dielectric constant and aluminum content,and the tanned powder was investigated by differential scanning calorimetry(DSC),thermogravimetric(TG)analysis,and FT-IR spectroscopy.For the skin piece system,the pH and aluminum content of tanning effluents were also determined,and at the same time,DSC,TG,SEM,FT-IR and shrinkage temperature were used to illustrate the actions of microwaves on the structure and properties of the tanned pieces.The results show that aluminum reactivity in the penetration and binding process of collagen fibers in hide powder and skin pieces improved using microwave treatment.The residual aluminum content was greatly reduced by microwave heating action,and the increased amount of aluminum with evener distribution was observed in the tanned products.Microwave irradiation also resulted in the tanned products with better thermal stability and thermal decomposition resistance.This work further promotes application of microwave treatments for aluminumbased tanning in leather industry.
文摘The global demand for renewable and affordable feed-stocks,combined with the worldwide targets for reduc-ing carbon emissions,is the driving force behind a breakthrough in resource revolution and GreenTech innovations[1].Owing to the vast reserves and short growing cycle,utilizing lignocellulosic biomass as an alternative to petroleum and environmentally friendly feedstock to furnish bioenergy and biomaterials is key to building a more sustainable future.Lignocellulose mainly contains three biopolymers,i.e.,cellulose,hemicellulose and lignin.Over the centuries,utilization of lignocellu-lose has crossed its possible molecular scale ranging from 101 m,as the original matrix,to 10-10 m,as a mono-meric molecule.
基金This work was financially supported by the National Key R&D Program(2017YFB0308500).
文摘Dialdehyde sodium alginate(DSA)is an alternative chrome-free tanning material for fur production.To obtain satisfactory resultant fur and provide suggestions for the usage of DSA in fur making,the general properties of DSA tanned sheep fur were systematically investigated.The tanning mechanism of DSA was analyzed and it was verified that DSA was mainly combined with collagen fiber by forming Schiff base covalent bonds while supplemented by a small number of hydrogen bonds and ionic bonds.Due to the acid sensitivity of Schiff base structure,DSA tanned fur had poor resistance to acid rinsing but had excellent resistance to washing and good fatliquoring performance.Also,it had good resistances to yellowing and reductant.After being retanned by chrome tanning agent,the fur was capable of enduring a high-temperature dyeing process(68°C for 8 h).Overall,DSA tanned sheep fur had favorable properties under appropriate post-tanning processing conditions to manufacture light-colored or dark-colored fur products with desirable physical properties.
基金National Natural Science Foundation of China(No.21576171).
文摘Since microwave irradiation could promote hydrolysis and olation of chromium tanning liquor,but the influence of microwave on chromium complex component in the liquor was still unknown.Chromium sulphate solution(0%basicity)and 33%basicity chromium tanning liquor were subjected microwave(MW)and water bath(WB)heating,and the samples without any warming were regarded as control.Ion exchange chromatography(IEC)and gel filtration chromatography(GFC)were used to measure the charge composition and molecular size of chromium complexes in each sample.FT-IR was used to characterize the structure of chromium complexes in each composition separated by IEC.Moreover,the chromium tanning liquor after warming was used in hide powder tanning trials to illustrate whether microwave would affect its tanning ability.The results show there are more high positive charge and large molecular size complexes in chromium tanning liquor after warming but the phenomena are more significant in MW samples compared with WB due to non-thermal effect of microwave.In addition,microwave has more powerful effect on 33%basicity chromium tanning liquor hydrolysis and olation to generate larger molecular size complexes.In FT-IR results,the combination pattern between chromium and ligands are changed after warming but there is no difference between WB and MW.The chromium exhaustion and thermal stability of hide powder tanned with chromium tanning liquor after microwave irradiation are both higher.It could conclude that both thermal and non-thermal effects of microwave promote the process together,and the nonthermal effect leads to more high positive charge and large molecular size complexes and has stronger influence on high polarity system.In short,this work would provide theoretical basis for applying microwave in tanning agent modification and chrome tanning process further.
