Aqueous zinc metal batteries are regarded as the most promising energy storage system due to their advantages of high safety,low cost,and high theoretical capacity.However,the growth of dendrites and the occurrence of...Aqueous zinc metal batteries are regarded as the most promising energy storage system due to their advantages of high safety,low cost,and high theoretical capacity.However,the growth of dendrites and the occurrence of side reactions hinder the development of zinc metal batteries.Despite previous attempts to design advanced hydrogel electrolytes,achieving high mechanical performance and ionic conductivity of hydrogel electrolytes has remained challenging.In this work,a hydrogel electrolyte with an ionic crosslinked network is prepared by carboxylic bacterial cellulose fiber and imidazole-type ionic liquid,following by a covalent network of polyacrylamide.The hydrogel electrolyte possesses a superior ionic conductivity of 43.76 mS cm^(−1),leading to a Zn^(2+)migration number of 0.45,and high mechanical performance with an elastic modulus of 3.48 GPa and an elongation at breaking of 38.36%.More importantly,under the anion-coordination effect of the carboxyl group in bacterial cellulose and[BF4]−in imidazole-type ionic liquid,the solvation sheath of hydrated Zn^(2+)ions and the nucleation overpotential of Zn plating are regulated.The results of cycled testing show that the growth of zinc dendrites is effectively inhibited and the generation of irreversible by-products is reduced.With the carboxylic bacterial cellulose-based hydrogel electrolyte,the Zn||Zn symmetric batteries offer good cyclability as well as Zn||Ti batteries.展开更多
Bamboo fibers(BFs),with features of renewability and biodegradability,have been widely used in paper-making products.In order to improve the mechanical properties and water absorption behaviors of the BF paper,bacteri...Bamboo fibers(BFs),with features of renewability and biodegradability,have been widely used in paper-making products.In order to improve the mechanical properties and water absorption behaviors of the BF paper,bacterial cellulose nanofibers(BCNFs)as environmentally friendly nano-fibrillated cellulose(NFC)were combined with BFs.The structures and properties of the BF/BCNF composite paper were characterized by field emission scanning electron microscopy(FE-SEM),X-ray diffraction(XRD),Fourier transforms infrared(FTIR)spectroscopy,mechanical tests,pore size tests,and water absorption tests.The results indicated that the addition of BCNFs could significantly improve the water absorption capacity and mechanical properties.The water absorption ratio of the BF/BCNF composite paper with a BCNF mass fraction of 9%comes to 443%,about 1.33 times that of the pure BF paper.At the same BCNF content,the tensile strength of the BF/BCNF composite paper in dry and wet states was 12.37 MPa and 200.9 kPa,respectively,increasing by 98.24%and 136.91%as compared with that of the BF paper.展开更多
Degradable industrial packaging foam trays made from cellulose fibers were fabricated using a hot-press baking process.Bleached softwood pulp fibers with a concentration of 30%were dispersed at a high speed under the ...Degradable industrial packaging foam trays made from cellulose fibers were fabricated using a hot-press baking process.Bleached softwood pulp fibers with a concentration of 30%were dispersed at a high speed under the action of a dispersant.The effects of the dispersant dosage of the fibers on the porosity,foam density,and static compression characteristics were discussed.Furthermore,the effects of the reinforcing adhesive including polyvinyl alcohol(PVA),and cassava starch on the physical and mechanical properties of the foam trays were studied,as well as the relationship between these properties and the microstructure of the foam trays.The dispersant enhanced the rheological and blistering properties of the fiber dispersion.As the dispersant dosage increased from 2%to 4%,the foam density gradually increased and the compressive strain performance and residual compressive strain of the foam trays decreased.Under the condition of constant dosage of dispersant,increasing the fiber proportion from 67%to 77%improved the porosity and foam density and slightly reduced the static compression performance.In additioton,the static compression resistance of the foamed materials was improved by increasing the PVA dosage since PVA was beneficial for improving the strength of the foam trays.展开更多
It is very difficult to directly spin the lignocellulose without pretreatment.Ionic liquids(ILs)are promising solvent to dissolve lignocellulose to prepare cellulose fiber.However,the degree of cellulose polymerizatio...It is very difficult to directly spin the lignocellulose without pretreatment.Ionic liquids(ILs)are promising solvent to dissolve lignocellulose to prepare cellulose fiber.However,the degree of cellulose polymerization(DP)is reduced when lignocellulose is dissolved in ILs,and the lignin removal rate is low.The elongation at break and tensile strength of the fibers obtained by spinning the lignocellulose dissolved in ILs are poor.In this paper,preparing cellulose fiber directly from lignocellulose based on dissolving corn stalk via[C4mim]Cl-L-arginine binary system is achieved.It shows that the removal rate of lignin can reach 92.35%and the purity of cellulose can reach 85.32%after corn stalk was dissolved at 150℃C for 11.5 h when the mass fraction of arginine is 2.5%.The elongation at break of fiber reached 10.12%and the tensile strength reached 420 MPa.It is mainly due to the fact that L-arginine not only inhibits the degradation of cellulose but also promotes the delignination.Without any pulping or pretreatment,preparing cellulose fibers via direct dissolution and extrusion may provide a simple and effective way to prepare many novel cellulose materials.展开更多
Cotton fibers are the main raw materials of the textile industry.Exogenous superior fiber genes have been introduced into upland cotton to develop high-yield cultivars with excellent fiber quality.We used a single chr...Cotton fibers are the main raw materials of the textile industry.Exogenous superior fiber genes have been introduced into upland cotton to develop high-yield cultivars with excellent fiber quality.We used a single chromosomal segment on the chromosome A07 substitution line SL7,with high fiber strength,to investigate the molecular mechanism underlying its fiber quality.RNA-seq and KEGG analysis showed that 70 differentially expressed genes were enriched in plant hormone transduction pathways,including auxin,ethylene and abscisic acid,in fibers at 10 days post-anthesis(DPA).Among these,fiberdevelopment related transcription factors MYB and NAC,including Gh_A11G0981(MYB108),Gh_A03G0887(NAC029),and Gh_A08G1691(NAC021),were significantly upregulated in SL7,as were numerous cellulose synthase-like(CSL)genes involved in non-cellulose polysaccharide and cell wall synthesis.The hemicellulose content of SL7 was significantly higher than that of L22,an upland cotton cultivar.These results suggest that key genes in the introgressed chromosomal segment of SL7 regulate the expression of transcription-factor genes via hormone-transduction pathways,thereby inducing the expression of genes involved in secondary wall synthesis and ultimately improving fiber quality.This study has shed light on the molecular mechanism of fiber development and will contribute to the improvement of fiber quality of upland cotton by molecular breeding.展开更多
Conductive ionic hydrogels(CIH)have been widely studied for the development of stretchable electronic devices,such as sensors,electrodes,and actuators.Most of these CIH are made into 3D or 2D shape,while 1D CIH(hydrog...Conductive ionic hydrogels(CIH)have been widely studied for the development of stretchable electronic devices,such as sensors,electrodes,and actuators.Most of these CIH are made into 3D or 2D shape,while 1D CIH(hydrogel fibers)is often difficult to make because of the low mechanical robustness of common CIH.Herein,we use gel spinning method to prepare a robust CIH fiber with high strength,large stretchability,and good conductivity.The robust CIH fiber is drawn from the composite gel of sodium polyacrylate(PAAS)and sodium carboxymethyl cellulose(CMC).In the composite CIH fiber,the soft PAAS presents good conductivity and stretchability,while the rigid CMC significantly enhances the strength and toughness of the PAAS/CMC fiber.To protect the conductive PAAS/CMC fiber from damage by water,a thin layer of hydrophobic polymethyl acrylate(PMA)or polybutyl acrylate(PBA)is coated on the PAAS/CMC fiber as a water-resistant and insulating cover.The obtained PAAS/CMC-PMA and PAAS/CMC-PBA CIH fibers present high tensile strength(up to 28 MPa),high tensile toughness(up to 43 MJ/m~3),and good electrical conductivity(up to 0.35 S/m),which are useful for textile-based stretchable electronic devices.展开更多
This study examined the effects of the enzyme cellulose on a few single jersey and interlock 100% flax t-shirts, two different styles of knit children’s clothes that differ in both their chemical and mechanical chara...This study examined the effects of the enzyme cellulose on a few single jersey and interlock 100% flax t-shirts, two different styles of knit children’s clothes that differ in both their chemical and mechanical characteristics. Clothing samples were dyed using reactive colours and then subjected to normal acid cellulose enzyme treatment procedures. We evaluated some physical and mechanical features before and after cellulose treatments, then compared these characteristics. Its cellulose enzymatic processing enhances some mechanical properties of fibre knitwear, such as pilling resistance and retention of water. Some characteristics of fibre-knitted clothing, such as fabric weight, fabric thickness, fabric burst resistance, and seam tensile strength of T-shirt side seams, are reduced by cellulose enzyme treatment at a manageable rate. Compared to single-jersey all-fiber children’s T-shirts, interlocking 100% flax children’s T-shirts have a better effect of the enzyme cellulose treatment on the majority of physical and mechanical attributes.展开更多
The effects of coagulation conditions on tensile properties of the regenerated cellulose fibers prepared by wet-spinning from NaOH/thiourea/urea(8∶6.5∶8 by weight)aqueous solvent were investigated by tensile tester,...The effects of coagulation conditions on tensile properties of the regenerated cellulose fibers prepared by wet-spinning from NaOH/thiourea/urea(8∶6.5∶8 by weight)aqueous solvent were investigated by tensile tester,X-ray diffraction(XRD),and scanning electron microscope(SEM).The results show that the tensile properties of the as-spun fibers change with the coagualtion concentration,temperature,and time.When the spinning solution is coagulated in 10% H2SO4/12.5% Na2SO4 aqueous solution,the as-spun fibers have a typical structure of cellulose II,a circular cross-section,and homogeneous morphological structure.展开更多
Polypyrrole(PPy)@cellulose fiber-based composites have been widely investigated as electrode materials for use in flexible supercapacitors.However,they cannot readily provide high specific capacitance and cyclic stabi...Polypyrrole(PPy)@cellulose fiber-based composites have been widely investigated as electrode materials for use in flexible supercapacitors.However,they cannot readily provide high specific capacitance and cyclic stability owing to their inherent drawbacks,such as high resistance,Weber impedance,and volume expansion or collapse during charging/discharging.In this study,iron oxyhydroxide(FeOOH)is incorporated in the abovementioned composite to decrease the equivalent series resistance,charge transfer resistance,and Weber impedance,thereby enhancing electron transfer and ion diffusion,which results in superior electrochemical performance.The PPy-wrapped FeOOH@cellulose fiber-based composite electrode with the molar ratio of FeSO_(4) to NaBH4 of 1∶1 exhibits a high specific capacitance of 513.8 F/g at a current density of 0.2 A/g,as well as an excellent capacitance retention of 89.4% after 1000 cycles.展开更多
This study was conducted to evaluate the effectiveness of enzymes in purifying and reducing the degree of polymerization of cellulose for the production of dissolving pulp.Our goal was to determine the contributions o...This study was conducted to evaluate the effectiveness of enzymes in purifying and reducing the degree of polymerization of cellulose for the production of dissolving pulp.Our goal was to determine the contributions of xylanase(X)and endoglucanase(EG)in the treatment of pulp,specifically by quantifying the formation of soluble and insoluble reducing sugars using the dinitrosalycilic acid(DNS)test.Predominantly,the release of soluble reducing sugars(RSSol)was enhanced after xylanase treatment,while endoglucanase(EG)treatment led to changes in insoluble reducing sugars(RSIns).The maximum synergism was observed for RSIns when a high ratio of endoglucanase to xylanase(320EG:5X/g pulp)was used.The relative contribution of endoglucanase to RSins was determined to be 15.6%of the total reducing sugar.The viscosity of pulps treated with xylanase decreased only by 7%,whereas endoglucanase treatment significantly reduced viscosity by 45%.Modifications in the particle size were observed after pulp treatment with the combination of endoglucanase and xylanase.In summary,the DNS test is a rapid and effective method for evaluating the efficiency of enzyme treatments on pulps.The measurement of RSIns correlates with changes in pulp viscosity to different extents,providing valuable insights into the effectiveness of enzyme treatments.展开更多
In this paper, fibrillation properties of solvent - spun cellulose fiber and some influencing factors are analyzed based on the experiment results. It is pointed out that special textile styles and aesthetic appearanc...In this paper, fibrillation properties of solvent - spun cellulose fiber and some influencing factors are analyzed based on the experiment results. It is pointed out that special textile styles and aesthetic appearance could be obtained by controlling the fibrillation.展开更多
Carboxymethyl cellulose(CMC) fibers were produced by extruding the CMC solution into the metal salt coagulation bath and collected with a winding machine.It was found that copper chloride,ferric chloride,cerium chlori...Carboxymethyl cellulose(CMC) fibers were produced by extruding the CMC solution into the metal salt coagulation bath and collected with a winding machine.It was found that copper chloride,ferric chloride,cerium chloride,lanthanum chloride and aluminum nitrate solution could be used as coagulation bath to prepare CMC fibers,whereas the metal salt solutions,such as nickel chloride,zinc chloride,calcium chloride and magnesium chloride,could not.The fiber formation is due to the coordination between the carboxylates of CMC and metal ion.Fourier transform infrared spectroscopy(FTIR) was applied to studying the coordination mode of CMC and metal ion.The metal salt concentration,pH value and temperature of the coagulation bath affect the tenacity and elongation of the fiber.CMC fibers show good water uptake ability and can adsorb water more than 200% of its own weight.The mechanical behaviors of CMC fiber show dependence on environment humidity.展开更多
Cellulose whiskers were isolated from kenaf (Hibiscus cannabinus L.) bast fibers via sulfuric acid and hydrochloric acid hydrolysis. Raw kenaf bast, NaOH treated, bleached fibers, sulfuric acid whiskers (SAW) and hydr...Cellulose whiskers were isolated from kenaf (Hibiscus cannabinus L.) bast fibers via sulfuric acid and hydrochloric acid hydrolysis. Raw kenaf bast, NaOH treated, bleached fibers, sulfuric acid whiskers (SAW) and hydrochloric acid whiskers (HClW) morphology, functional groups, crystallinity, and thermal stability were characterized. The TEM images showed that the sulfuric acid and HCl whiskers have average diameters and length range of 3 nm and 100 - 500 nm, respectively. The FTIR study indicated that during the conversion process, most of the hemicellulose and almost all the lignin were removed by the NaOH and subsequent bleaching treatments. The crystallinity of HCl whiskers was found to be higher (84%) than that of sulfuric acid whiskers (72%). Thermogravimetric analysis indicated that HCl whiskers had better thermal stability than the sulfuric acid ones. In addition, a two-stage decomposition behavior was revealed by TGA in the sulfuric acid whiskers because of incorporation of the sulfate group with the cellulose crystals.展开更多
This study was aimed to determine the mechanical strength of composites made from Agave cantala with an unsaturated polyester matrix and microcrystalline cellulose.Cantala fiber(CF)was treated with 6%Na OH with immers...This study was aimed to determine the mechanical strength of composites made from Agave cantala with an unsaturated polyester matrix and microcrystalline cellulose.Cantala fiber(CF)was treated with 6%Na OH with immersion times of 0 h(UF),3 h(AK3),6 h(AK6),9 h(AK9),and12 h(AK12).Thermogravimetric analysis(TGA)analysis shows that treated CF has higher thermal stability than CF without treatment.Cantala fiber was tested by X-ray diffraction.After alkali treatment with a 6-h soaking,it had a crystallinity index of 73.65%.Scanning electron microscopy(SEM)showed that the fibers were cleaner after alkali treatment because hemicellulose,wax,and other impurities were removed.Examination of the contact angle and surface energy showed that treated CF has smaller contact angles and greater surface energy.展开更多
Fibers are used in various areas for improving the performance of different materials, commonly used are synthetic fibers and glass fibers. More and more sustainable alternatives are required to reduce energy consumpt...Fibers are used in various areas for improving the performance of different materials, commonly used are synthetic fibers and glass fibers. More and more sustainable alternatives are required to reduce energy consumption and the carbon footprint. Traditional natural fibers (like hemp or flax) very often do not fulfill requirements for construction purposes like resistance to elevated temperature or lacking purity. Also mechanical properties of natural fibers are influenced by factors like harvesting, kink bands, climate and growth conditions. Lenzing AG has put a lot of efforts into developing a sustainable fiber overcoming the above mentioned issues. The raw material for TENCEL is wood, which is transformed into a fiber of pure cellulose in an economy friendly process as been proven by a life cycle assessment. The properties of a composite material are highly dependent on parameters like mechanical fiber properties, fiber diameter, quality of fiber dispersion and fiber matrix adhesion. Keeping these properties constant throughout the whole composite part is the factor to success. The diameter as well as the mechanical properties of TENCEL fibers is kept within a very narrow range thanks to the unique manufacturing process. It was shown that the fiber dispersion of TENCEL as well as the fiber matrix adhesion is better than for natural fibers.展开更多
Influence factors on the biodegradation of cellulose fiber composite paperboard were studied experimentally and explained theoretically. The results show that the inorganic salts as nutriment added in the soil lixiviu...Influence factors on the biodegradation of cellulose fiber composite paperboard were studied experimentally and explained theoretically. The results show that the inorganic salts as nutriment added in the soil lixivium, the ratio of C/N, the temperature for biodegradation and content of basaltic fibers in the composite paperboard are the main influence factors.展开更多
Cellulose nanofibrils(CNFs) are a type of natural nanomaterials extracted from plants and animals that have expanding applications in numerous areas benefiting from their inherent properties of renewability,biodegrada...Cellulose nanofibrils(CNFs) are a type of natural nanomaterials extracted from plants and animals that have expanding applications in numerous areas benefiting from their inherent properties of renewability,biodegradability,and sustainability.For energy consumption reduction,CNFs were extracted from raw jute fibers,which were not pretreated in a hot alkali or acid solution,by TEMPOmediated oxidation.Synchrotron radiation wide-angle scattering was performed to realize the crystallization of the CNF crystallites;Fourier transform infrared spectroscopy,transmission electron microscopy,and fieldemission scanning electron microscopy were used to characterize the changes in chemical groups and visualized morphology of CNFs.The simplified preparation and shortened cycle should further help the study of the structure–function relationship of jute CNFs subjected to chemical modification.展开更多
In this study, bio-yogurts, which contain L. acidophilus and Bifidobacterium animalis subsp. lactis, were produced with cellulose fiber (CF) addition at a various level (0%, 0.5%, 1% and 2%) and stored at 4°C ...In this study, bio-yogurts, which contain L. acidophilus and Bifidobacterium animalis subsp. lactis, were produced with cellulose fiber (CF) addition at a various level (0%, 0.5%, 1% and 2%) and stored at 4°C ± 1°C for 20 days. Bio-yogurts were analysed 1, 10 and 20 days after production. The storage period significantly influenced overall properties of the samples. Addition of CF has positively affected the physical and textural properties of yoghurt, such as serum separation, water holding capacity, viscosity, firmness, adhesiveness, cohesiveness, springiness, gumminess and chewiness (p < 0.05). It also slightly stimulated the development of probiotic bacteria (p < 0.05). Bio-yogurt, which contains 0.5% CF in sensory aspect, is the most appreciated.展开更多
以聚丙烯腈(PAN)/纤维素(Cellulose)复合纤维为碳纤维前驱体,通过预氧化、碳化工艺处理,制备了PAN/Cellulose基复合碳纤维,对前驱体复合纤维PAN/Cellulose与所得碳纤维的结构及性能进行了研究。结果表明:相比PAN纤维,PAN/Cellulose复合...以聚丙烯腈(PAN)/纤维素(Cellulose)复合纤维为碳纤维前驱体,通过预氧化、碳化工艺处理,制备了PAN/Cellulose基复合碳纤维,对前驱体复合纤维PAN/Cellulose与所得碳纤维的结构及性能进行了研究。结果表明:相比PAN纤维,PAN/Cellulose复合纤维的结晶度和晶粒尺寸减小,环化反应活化能降低了约40 k J/mol;Cellulose具有促进石墨化的效果,PAN/Cellulose基复合碳纤维的电阻率较PAN基碳纤维提高了112.7%,这将有助于拓展PAN基碳纤维在民用隔热材料领域的应用。展开更多
Nowadays, the material recycling is a growing trend in development of building materials and therefore using of secondary raw materials for production new building materials is in accordance with sustainable developme...Nowadays, the material recycling is a growing trend in development of building materials and therefore using of secondary raw materials for production new building materials is in accordance with sustainable development in civil engineering. Therefore, it is increasingly becoming crucial to accelerate the transition from application of non-renewable sources of raw materials to renewable raw materials. One fast renewable resource is natural plant fibers. The use of the cellulosic fibers as environmentally friendly material in building products contributes to the environmental protection and saves non-renewable resources of raw materials. Wood fibers and recycled cellulose fibers of waste paper appear as suited reinforcing elements for cement-based materials. In this paper, there is used application of Fourier transform infrared spectroscopy (FTIR) on cellulose fibers coming from different sources. FTIR spectra of cellulose fiber samples are investigated and compared with reference sample of cellulose.展开更多
基金National Natural Science Foundation of China(51903113,51763014,and 52073133)China Postdoctoral Science Foundation(2022T150282,2019M663858)Program for Hongliu Excellent and Distinguished Young Scholars at Lanzhou University of Technology.
文摘Aqueous zinc metal batteries are regarded as the most promising energy storage system due to their advantages of high safety,low cost,and high theoretical capacity.However,the growth of dendrites and the occurrence of side reactions hinder the development of zinc metal batteries.Despite previous attempts to design advanced hydrogel electrolytes,achieving high mechanical performance and ionic conductivity of hydrogel electrolytes has remained challenging.In this work,a hydrogel electrolyte with an ionic crosslinked network is prepared by carboxylic bacterial cellulose fiber and imidazole-type ionic liquid,following by a covalent network of polyacrylamide.The hydrogel electrolyte possesses a superior ionic conductivity of 43.76 mS cm^(−1),leading to a Zn^(2+)migration number of 0.45,and high mechanical performance with an elastic modulus of 3.48 GPa and an elongation at breaking of 38.36%.More importantly,under the anion-coordination effect of the carboxyl group in bacterial cellulose and[BF4]−in imidazole-type ionic liquid,the solvation sheath of hydrated Zn^(2+)ions and the nucleation overpotential of Zn plating are regulated.The results of cycled testing show that the growth of zinc dendrites is effectively inhibited and the generation of irreversible by-products is reduced.With the carboxylic bacterial cellulose-based hydrogel electrolyte,the Zn||Zn symmetric batteries offer good cyclability as well as Zn||Ti batteries.
基金Open Project Program of Key Laboratory of Yarn Materials Forming and Composite Processing Technology of Zhejiang Province,China(No.MTC2020-10)。
文摘Bamboo fibers(BFs),with features of renewability and biodegradability,have been widely used in paper-making products.In order to improve the mechanical properties and water absorption behaviors of the BF paper,bacterial cellulose nanofibers(BCNFs)as environmentally friendly nano-fibrillated cellulose(NFC)were combined with BFs.The structures and properties of the BF/BCNF composite paper were characterized by field emission scanning electron microscopy(FE-SEM),X-ray diffraction(XRD),Fourier transforms infrared(FTIR)spectroscopy,mechanical tests,pore size tests,and water absorption tests.The results indicated that the addition of BCNFs could significantly improve the water absorption capacity and mechanical properties.The water absorption ratio of the BF/BCNF composite paper with a BCNF mass fraction of 9%comes to 443%,about 1.33 times that of the pure BF paper.At the same BCNF content,the tensile strength of the BF/BCNF composite paper in dry and wet states was 12.37 MPa and 200.9 kPa,respectively,increasing by 98.24%and 136.91%as compared with that of the BF paper.
文摘Degradable industrial packaging foam trays made from cellulose fibers were fabricated using a hot-press baking process.Bleached softwood pulp fibers with a concentration of 30%were dispersed at a high speed under the action of a dispersant.The effects of the dispersant dosage of the fibers on the porosity,foam density,and static compression characteristics were discussed.Furthermore,the effects of the reinforcing adhesive including polyvinyl alcohol(PVA),and cassava starch on the physical and mechanical properties of the foam trays were studied,as well as the relationship between these properties and the microstructure of the foam trays.The dispersant enhanced the rheological and blistering properties of the fiber dispersion.As the dispersant dosage increased from 2%to 4%,the foam density gradually increased and the compressive strain performance and residual compressive strain of the foam trays decreased.Under the condition of constant dosage of dispersant,increasing the fiber proportion from 67%to 77%improved the porosity and foam density and slightly reduced the static compression performance.In additioton,the static compression resistance of the foamed materials was improved by increasing the PVA dosage since PVA was beneficial for improving the strength of the foam trays.
基金This research was financially supported by the National Natural Science Foundation of China(No.21878292,No.21606240,No.21878314)K.C.Wong Education Foundation(No.GJTD-2018-04)the Strategic Priority Research Program of Chinese Academy of Science(No.XDA21060300).
文摘It is very difficult to directly spin the lignocellulose without pretreatment.Ionic liquids(ILs)are promising solvent to dissolve lignocellulose to prepare cellulose fiber.However,the degree of cellulose polymerization(DP)is reduced when lignocellulose is dissolved in ILs,and the lignin removal rate is low.The elongation at break and tensile strength of the fibers obtained by spinning the lignocellulose dissolved in ILs are poor.In this paper,preparing cellulose fiber directly from lignocellulose based on dissolving corn stalk via[C4mim]Cl-L-arginine binary system is achieved.It shows that the removal rate of lignin can reach 92.35%and the purity of cellulose can reach 85.32%after corn stalk was dissolved at 150℃C for 11.5 h when the mass fraction of arginine is 2.5%.The elongation at break of fiber reached 10.12%and the tensile strength reached 420 MPa.It is mainly due to the fact that L-arginine not only inhibits the degradation of cellulose but also promotes the delignination.Without any pulping or pretreatment,preparing cellulose fibers via direct dissolution and extrusion may provide a simple and effective way to prepare many novel cellulose materials.
基金the National Natural Science Foundation of China(31601345 and 31671742)the Earmarked Fund for China Agriculture Research System(CARS-15-05)+1 种基金the Taishan Scholar Project of Shandong Province(ts201511070)the Innovation Project in Shandong Academy of Agricultural Sciences(CXGC2016A01).
文摘Cotton fibers are the main raw materials of the textile industry.Exogenous superior fiber genes have been introduced into upland cotton to develop high-yield cultivars with excellent fiber quality.We used a single chromosomal segment on the chromosome A07 substitution line SL7,with high fiber strength,to investigate the molecular mechanism underlying its fiber quality.RNA-seq and KEGG analysis showed that 70 differentially expressed genes were enriched in plant hormone transduction pathways,including auxin,ethylene and abscisic acid,in fibers at 10 days post-anthesis(DPA).Among these,fiberdevelopment related transcription factors MYB and NAC,including Gh_A11G0981(MYB108),Gh_A03G0887(NAC029),and Gh_A08G1691(NAC021),were significantly upregulated in SL7,as were numerous cellulose synthase-like(CSL)genes involved in non-cellulose polysaccharide and cell wall synthesis.The hemicellulose content of SL7 was significantly higher than that of L22,an upland cotton cultivar.These results suggest that key genes in the introgressed chromosomal segment of SL7 regulate the expression of transcription-factor genes via hormone-transduction pathways,thereby inducing the expression of genes involved in secondary wall synthesis and ultimately improving fiber quality.This study has shed light on the molecular mechanism of fiber development and will contribute to the improvement of fiber quality of upland cotton by molecular breeding.
基金supported by the National Natural Science Foundation of China(No.21778052 and No.21975240)by the Natural Science Foundation of Anhui Province(No.1908085J19)the Talent Research Foundation of Hefei University(No.18-19RC08)。
文摘Conductive ionic hydrogels(CIH)have been widely studied for the development of stretchable electronic devices,such as sensors,electrodes,and actuators.Most of these CIH are made into 3D or 2D shape,while 1D CIH(hydrogel fibers)is often difficult to make because of the low mechanical robustness of common CIH.Herein,we use gel spinning method to prepare a robust CIH fiber with high strength,large stretchability,and good conductivity.The robust CIH fiber is drawn from the composite gel of sodium polyacrylate(PAAS)and sodium carboxymethyl cellulose(CMC).In the composite CIH fiber,the soft PAAS presents good conductivity and stretchability,while the rigid CMC significantly enhances the strength and toughness of the PAAS/CMC fiber.To protect the conductive PAAS/CMC fiber from damage by water,a thin layer of hydrophobic polymethyl acrylate(PMA)or polybutyl acrylate(PBA)is coated on the PAAS/CMC fiber as a water-resistant and insulating cover.The obtained PAAS/CMC-PMA and PAAS/CMC-PBA CIH fibers present high tensile strength(up to 28 MPa),high tensile toughness(up to 43 MJ/m~3),and good electrical conductivity(up to 0.35 S/m),which are useful for textile-based stretchable electronic devices.
文摘This study examined the effects of the enzyme cellulose on a few single jersey and interlock 100% flax t-shirts, two different styles of knit children’s clothes that differ in both their chemical and mechanical characteristics. Clothing samples were dyed using reactive colours and then subjected to normal acid cellulose enzyme treatment procedures. We evaluated some physical and mechanical features before and after cellulose treatments, then compared these characteristics. Its cellulose enzymatic processing enhances some mechanical properties of fibre knitwear, such as pilling resistance and retention of water. Some characteristics of fibre-knitted clothing, such as fabric weight, fabric thickness, fabric burst resistance, and seam tensile strength of T-shirt side seams, are reduced by cellulose enzyme treatment at a manageable rate. Compared to single-jersey all-fiber children’s T-shirts, interlocking 100% flax children’s T-shirts have a better effect of the enzyme cellulose treatment on the majority of physical and mechanical attributes.
文摘The effects of coagulation conditions on tensile properties of the regenerated cellulose fibers prepared by wet-spinning from NaOH/thiourea/urea(8∶6.5∶8 by weight)aqueous solvent were investigated by tensile tester,X-ray diffraction(XRD),and scanning electron microscope(SEM).The results show that the tensile properties of the as-spun fibers change with the coagualtion concentration,temperature,and time.When the spinning solution is coagulated in 10% H2SO4/12.5% Na2SO4 aqueous solution,the as-spun fibers have a typical structure of cellulose II,a circular cross-section,and homogeneous morphological structure.
基金This study was supported by the National Natural Science Foundation of China(grant no.31770620).
文摘Polypyrrole(PPy)@cellulose fiber-based composites have been widely investigated as electrode materials for use in flexible supercapacitors.However,they cannot readily provide high specific capacitance and cyclic stability owing to their inherent drawbacks,such as high resistance,Weber impedance,and volume expansion or collapse during charging/discharging.In this study,iron oxyhydroxide(FeOOH)is incorporated in the abovementioned composite to decrease the equivalent series resistance,charge transfer resistance,and Weber impedance,thereby enhancing electron transfer and ion diffusion,which results in superior electrochemical performance.The PPy-wrapped FeOOH@cellulose fiber-based composite electrode with the molar ratio of FeSO_(4) to NaBH4 of 1∶1 exhibits a high specific capacitance of 513.8 F/g at a current density of 0.2 A/g,as well as an excellent capacitance retention of 89.4% after 1000 cycles.
基金supported by CNPq(303416/2018-1)and FAPESP(2019/25867-3).
文摘This study was conducted to evaluate the effectiveness of enzymes in purifying and reducing the degree of polymerization of cellulose for the production of dissolving pulp.Our goal was to determine the contributions of xylanase(X)and endoglucanase(EG)in the treatment of pulp,specifically by quantifying the formation of soluble and insoluble reducing sugars using the dinitrosalycilic acid(DNS)test.Predominantly,the release of soluble reducing sugars(RSSol)was enhanced after xylanase treatment,while endoglucanase(EG)treatment led to changes in insoluble reducing sugars(RSIns).The maximum synergism was observed for RSIns when a high ratio of endoglucanase to xylanase(320EG:5X/g pulp)was used.The relative contribution of endoglucanase to RSins was determined to be 15.6%of the total reducing sugar.The viscosity of pulps treated with xylanase decreased only by 7%,whereas endoglucanase treatment significantly reduced viscosity by 45%.Modifications in the particle size were observed after pulp treatment with the combination of endoglucanase and xylanase.In summary,the DNS test is a rapid and effective method for evaluating the efficiency of enzyme treatments on pulps.The measurement of RSIns correlates with changes in pulp viscosity to different extents,providing valuable insights into the effectiveness of enzyme treatments.
文摘In this paper, fibrillation properties of solvent - spun cellulose fiber and some influencing factors are analyzed based on the experiment results. It is pointed out that special textile styles and aesthetic appearance could be obtained by controlling the fibrillation.
基金National Natural Science Foundation of China(No.51373032)Innovation Program of Shanghai Municipal Education Commission,China+1 种基金Fundamental Research Funds for the Central University,ChinaDHU Distinguished Young Professor Program,China
文摘Carboxymethyl cellulose(CMC) fibers were produced by extruding the CMC solution into the metal salt coagulation bath and collected with a winding machine.It was found that copper chloride,ferric chloride,cerium chloride,lanthanum chloride and aluminum nitrate solution could be used as coagulation bath to prepare CMC fibers,whereas the metal salt solutions,such as nickel chloride,zinc chloride,calcium chloride and magnesium chloride,could not.The fiber formation is due to the coordination between the carboxylates of CMC and metal ion.Fourier transform infrared spectroscopy(FTIR) was applied to studying the coordination mode of CMC and metal ion.The metal salt concentration,pH value and temperature of the coagulation bath affect the tenacity and elongation of the fiber.CMC fibers show good water uptake ability and can adsorb water more than 200% of its own weight.The mechanical behaviors of CMC fiber show dependence on environment humidity.
文摘Cellulose whiskers were isolated from kenaf (Hibiscus cannabinus L.) bast fibers via sulfuric acid and hydrochloric acid hydrolysis. Raw kenaf bast, NaOH treated, bleached fibers, sulfuric acid whiskers (SAW) and hydrochloric acid whiskers (HClW) morphology, functional groups, crystallinity, and thermal stability were characterized. The TEM images showed that the sulfuric acid and HCl whiskers have average diameters and length range of 3 nm and 100 - 500 nm, respectively. The FTIR study indicated that during the conversion process, most of the hemicellulose and almost all the lignin were removed by the NaOH and subsequent bleaching treatments. The crystallinity of HCl whiskers was found to be higher (84%) than that of sulfuric acid whiskers (72%). Thermogravimetric analysis indicated that HCl whiskers had better thermal stability than the sulfuric acid ones. In addition, a two-stage decomposition behavior was revealed by TGA in the sulfuric acid whiskers because of incorporation of the sulfate group with the cellulose crystals.
文摘This study was aimed to determine the mechanical strength of composites made from Agave cantala with an unsaturated polyester matrix and microcrystalline cellulose.Cantala fiber(CF)was treated with 6%Na OH with immersion times of 0 h(UF),3 h(AK3),6 h(AK6),9 h(AK9),and12 h(AK12).Thermogravimetric analysis(TGA)analysis shows that treated CF has higher thermal stability than CF without treatment.Cantala fiber was tested by X-ray diffraction.After alkali treatment with a 6-h soaking,it had a crystallinity index of 73.65%.Scanning electron microscopy(SEM)showed that the fibers were cleaner after alkali treatment because hemicellulose,wax,and other impurities were removed.Examination of the contact angle and surface energy showed that treated CF has smaller contact angles and greater surface energy.
文摘Fibers are used in various areas for improving the performance of different materials, commonly used are synthetic fibers and glass fibers. More and more sustainable alternatives are required to reduce energy consumption and the carbon footprint. Traditional natural fibers (like hemp or flax) very often do not fulfill requirements for construction purposes like resistance to elevated temperature or lacking purity. Also mechanical properties of natural fibers are influenced by factors like harvesting, kink bands, climate and growth conditions. Lenzing AG has put a lot of efforts into developing a sustainable fiber overcoming the above mentioned issues. The raw material for TENCEL is wood, which is transformed into a fiber of pure cellulose in an economy friendly process as been proven by a life cycle assessment. The properties of a composite material are highly dependent on parameters like mechanical fiber properties, fiber diameter, quality of fiber dispersion and fiber matrix adhesion. Keeping these properties constant throughout the whole composite part is the factor to success. The diameter as well as the mechanical properties of TENCEL fibers is kept within a very narrow range thanks to the unique manufacturing process. It was shown that the fiber dispersion of TENCEL as well as the fiber matrix adhesion is better than for natural fibers.
基金The work is funded by the science and research plant foundation of Hebei province educational committee (No.2002163).
文摘Influence factors on the biodegradation of cellulose fiber composite paperboard were studied experimentally and explained theoretically. The results show that the inorganic salts as nutriment added in the soil lixivium, the ratio of C/N, the temperature for biodegradation and content of basaltic fibers in the composite paperboard are the main influence factors.
基金supported by the National Nature Science Foundation of China(Nos.11505272,51773221,U1732123)Youth Innovation Promotion Association CAS(No.2017308)
文摘Cellulose nanofibrils(CNFs) are a type of natural nanomaterials extracted from plants and animals that have expanding applications in numerous areas benefiting from their inherent properties of renewability,biodegradability,and sustainability.For energy consumption reduction,CNFs were extracted from raw jute fibers,which were not pretreated in a hot alkali or acid solution,by TEMPOmediated oxidation.Synchrotron radiation wide-angle scattering was performed to realize the crystallization of the CNF crystallites;Fourier transform infrared spectroscopy,transmission electron microscopy,and fieldemission scanning electron microscopy were used to characterize the changes in chemical groups and visualized morphology of CNFs.The simplified preparation and shortened cycle should further help the study of the structure–function relationship of jute CNFs subjected to chemical modification.
文摘In this study, bio-yogurts, which contain L. acidophilus and Bifidobacterium animalis subsp. lactis, were produced with cellulose fiber (CF) addition at a various level (0%, 0.5%, 1% and 2%) and stored at 4°C ± 1°C for 20 days. Bio-yogurts were analysed 1, 10 and 20 days after production. The storage period significantly influenced overall properties of the samples. Addition of CF has positively affected the physical and textural properties of yoghurt, such as serum separation, water holding capacity, viscosity, firmness, adhesiveness, cohesiveness, springiness, gumminess and chewiness (p < 0.05). It also slightly stimulated the development of probiotic bacteria (p < 0.05). Bio-yogurt, which contains 0.5% CF in sensory aspect, is the most appreciated.
文摘以聚丙烯腈(PAN)/纤维素(Cellulose)复合纤维为碳纤维前驱体,通过预氧化、碳化工艺处理,制备了PAN/Cellulose基复合碳纤维,对前驱体复合纤维PAN/Cellulose与所得碳纤维的结构及性能进行了研究。结果表明:相比PAN纤维,PAN/Cellulose复合纤维的结晶度和晶粒尺寸减小,环化反应活化能降低了约40 k J/mol;Cellulose具有促进石墨化的效果,PAN/Cellulose基复合碳纤维的电阻率较PAN基碳纤维提高了112.7%,这将有助于拓展PAN基碳纤维在民用隔热材料领域的应用。
文摘Nowadays, the material recycling is a growing trend in development of building materials and therefore using of secondary raw materials for production new building materials is in accordance with sustainable development in civil engineering. Therefore, it is increasingly becoming crucial to accelerate the transition from application of non-renewable sources of raw materials to renewable raw materials. One fast renewable resource is natural plant fibers. The use of the cellulosic fibers as environmentally friendly material in building products contributes to the environmental protection and saves non-renewable resources of raw materials. Wood fibers and recycled cellulose fibers of waste paper appear as suited reinforcing elements for cement-based materials. In this paper, there is used application of Fourier transform infrared spectroscopy (FTIR) on cellulose fibers coming from different sources. FTIR spectra of cellulose fiber samples are investigated and compared with reference sample of cellulose.