Water-resistant films were prepared by coating the surface of regenerated cellulose films with castor oil-based polyurethane (PU)/ poly-(methacrylate-co-styrene) [P (MA-St)]. The effects of the ratio of PU to P (MA-St...Water-resistant films were prepared by coating the surface of regenerated cellulose films with castor oil-based polyurethane (PU)/ poly-(methacrylate-co-styrene) [P (MA-St)]. The effects of the ratio of PU to P (MA-St) copolymer on tensile strength (dry and wet states), vapor permeability, size stability, and water resistivity of the coated films were studied. The interfacial interaction between cellulose and the PU/P (MA-St) coating was analyzed using infrared (IR), ultraviolet (UV), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal analysis (DTA), and electron probe microanalysis (EPMA). The results indicated that the mechanical properties and water resistivity of the coated films significantly enhanced, and the biodegradability was displayed, when the ratio of PU to P (MA-St) was 8∶2 by weight. The chemical bonds and hydrogen bonds between the cellulose, PU, and the copolymer exist in the coated films. It is regarded that PU/P (MA-St) semi-interpenetrating polymer networks (IPNs) were formed, and a shared network of PU with both the cellulose and the coating in the coated film occurred simultaneously resulting in a strong bonding between the coating layer and the film.展开更多
The 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO)oxidized cellulose film(TOCF)has been attempted to be used as a substrate in electronic and optoelectronic devices,but the changes in the TOCF properties before and after...The 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO)oxidized cellulose film(TOCF)has been attempted to be used as a substrate in electronic and optoelectronic devices,but the changes in the TOCF properties before and after annealing treatment have usually been neglected during device fabrication.In this study,TOCF was treated in different atmospheres(air,vacuum,and N2)and at different temperatures,and the properties were investigated.The results indicate that the optical properties are slightly affected by atmosphere and temperature;only slight transmittance loss and haze increase have been observed when TOCF is exposed to an air atmosphere at temperatures of above 120℃.In contrast to the slight effects on the optical properties,cellulose degradation and a loss of film strength have been observed regardless of the atmosphere used when placed at temperatures of above 100℃.Specifically,TOCF was exposed to air,followed by N2 and vacuum atmospheres.Additional Fourier transform infrared(FT-IR)and nuclear magnetic resonance(NMR)results showed that increasing the temperature had no significant effect on the structure of TOCF.Therefore,the annealing temperature should be controlled at a temperature of lower than 100℃and a vacuum atmosphere is preferred.展开更多
Regenerated cellulose films with water-resistance were obtained by an improved method ofpreparing cellulose cuoxam solution from pulps of agricultural wastes (linters, wheat straw, reedand Bamao). Experimental results...Regenerated cellulose films with water-resistance were obtained by an improved method ofpreparing cellulose cuoxam solution from pulps of agricultural wastes (linters, wheat straw, reedand Bamao). Experimental results showed that the mechanical properties of both the dry. and wetfilms were excellent. Data from IR, SEM and tensile strength measurements implied that thesignificant improvement of water-resistance of the films was due to the cohesion between the thinTung oil covers with hydrophobicity and the regenerated cellulose films. The films werecompletely biodegraded after being buried in soil for 100 days. The transmittance of the filmsderived from linter and reed in visible band range were 80-90%.展开更多
The biodegradability of Aspergillus niger (A. niger), Mucor (M-305) and Trichoderma (T-311) strains on regenerated cellulose films in media was investigated. The results showed that T-311 strain isolated from soil adh...The biodegradability of Aspergillus niger (A. niger), Mucor (M-305) and Trichoderma (T-311) strains on regenerated cellulose films in media was investigated. The results showed that T-311 strain isolated from soil adhered on the cellulose film fragments has stronger degradation effect on the cellulose film than A. niger strain. The weights, molecular weights and tensile strengths of the cellulose films in both shake culture and solid media decreased with incubation time, accompanied by producing CO2 and saccharides. HPLC, IR and released CO2 analysis indicated that the biodegradation products of the regenerated cellulose films mainly contain oligosaccharides, cellobiose, glucose, arabinose, erythrose, glycerose, glycerol, ethanal, formaldehyde and organic acid, the end products were CO2 and water. After a month, the films were completely decomposed by fungi in the media at 30 degrees C.展开更多
The microstructure of bacterial cellulose nanofibers(BCNs)film affects its characteristic.One of several means to engineer the microstructure is by changing the BCNs size and fiber distribution through a high-pressure...The microstructure of bacterial cellulose nanofibers(BCNs)film affects its characteristic.One of several means to engineer the microstructure is by changing the BCNs size and fiber distribution through a high-pressure homogenizer(HPH)process.This research aimed to find out the effects of repetition cycles on HPH process towards BCNs film characteristics.To prepare BCNs films,a pellicle from the fermentation of pineapple peels waste with Acetobacter xylinum(A.xylinum)was extracted,followed by crushing the pellicle with a high-speed blender,thereafter,homogenized using HPH at 150 bar pressure with variations of 5,10,15,and 20 cycles.The BCNs films were then formed through the casting process and drying in the oven at 60°C for 8 h followed by structural,morphological,and optical properties investigation using X-ray diffraction(XRD),scanning electron microscopy(SEM)and Fourier transform infrared(FTIR)spectrometer along with BCNs films porosity,tensile and roughness test.The research showed that the effect of HPH cycle on BCNs resulted in the highest film tensile strength by 109.15 MPa with the lowest surface roughness(Ra)of 0.93±0.10μm at 10 cycles.The HPH process is effective in controlling BCNs film porosity level.The HPH cycles influence the crystalline index and crystallite size,slightly.展开更多
Due to the increased potential for application of natural biopolymers in the food industry,the goal of this study was to prospectively produce antimicrobial films using asparagus residue.In this study,cellulose was ex...Due to the increased potential for application of natural biopolymers in the food industry,the goal of this study was to prospectively produce antimicrobial films using asparagus residue.In this study,cellulose was extracted from asparagus residue,and then 3 cellulose solutions of 0.008,0.01 and 0.025 g/mL were applied to prepare films using a phase inversion process.Films were characterized by Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),thermal gravimetric analysis(TGA)and scanning electron microscopy(SEM).The film produced by 0.01 g/mL asparagus cellulose solution exhibited a swelling ratio of 125.4%and excellent antimicrobial activity against Escherichia coli and Staphylococcus aureus using the disk agar diffusion method.This study presents a promising method for producing antimicrobial films with asparagus residue.展开更多
SiO_2/TiO_2/methylcellulose composite materials processed by the sol-gel technique were studied for optical waveguide applications. With the help of methylcellulose, an organic binder, SiO2/TiO2/methylcellulose hybrid...SiO_2/TiO_2/methylcellulose composite materials processed by the sol-gel technique were studied for optical waveguide applications. With the help of methylcellulose, an organic binder, SiO2/TiO2/methylcellulose hybrid thick films were prepared by a single spin-coating processes. After annealing at 70 °C for an hour, 2.5-μm crack-free and dense organic-inorganic hybrid optical films with a refractive index of 1.537 were achieved. Optical losses of plane waveguide made up of those films and ordinary slide glass substrate are around 0.3 dB/cm at 650 nm. Scanning electronmicroscopy (SEM) and UV-visible spectroscopy (UV-VIS), have been used to characterize the thick films.展开更多
High strength cellulose composite films with antibacterial activities were prepared by dispersing montmorillonites （MMT） into cellulose solution in LiOH/urea aqueous solvent followed by regeneration in ethanol coagu...High strength cellulose composite films with antibacterial activities were prepared by dispersing montmorillonites （MMT） into cellulose solution in LiOH/urea aqueous solvent followed by regeneration in ethanol coagulation bath, and then by soaking in 5 wt% hexadecylpyridine bromide ethanol solutions to induce the antibacterial action. The cellulose/MMT composite films were characterized by field emission scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, FTIR, UV-spectra, wide angle X-ray diffraction and mechanical test. The results revealed that MMT was dispersed well in the cellulose matrix to form layer structure with a thickness of approximately 3 nm. The mechanical properties of the cellulose/MMT composite films were significantly improved to achieve 132 MP for tensile strength as a result of the MMT delamination. The hexadecylpyridine bromide was fixed well in the cellulose/MMT matrix through cation exchange, leading to the excellent antibacterial activities against Staphylococcus aureus and Escherichia coli, which is important in their practical applications.展开更多
文摘Water-resistant films were prepared by coating the surface of regenerated cellulose films with castor oil-based polyurethane (PU)/ poly-(methacrylate-co-styrene) [P (MA-St)]. The effects of the ratio of PU to P (MA-St) copolymer on tensile strength (dry and wet states), vapor permeability, size stability, and water resistivity of the coated films were studied. The interfacial interaction between cellulose and the PU/P (MA-St) coating was analyzed using infrared (IR), ultraviolet (UV), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal analysis (DTA), and electron probe microanalysis (EPMA). The results indicated that the mechanical properties and water resistivity of the coated films significantly enhanced, and the biodegradability was displayed, when the ratio of PU to P (MA-St) was 8∶2 by weight. The chemical bonds and hydrogen bonds between the cellulose, PU, and the copolymer exist in the coated films. It is regarded that PU/P (MA-St) semi-interpenetrating polymer networks (IPNs) were formed, and a shared network of PU with both the cellulose and the coating in the coated film occurred simultaneously resulting in a strong bonding between the coating layer and the film.
基金National Natural Science Foundation of China(31770632)the Innovation Fund from Fujian Agriculture and Forestry University(CXZX2017296 and CXZX2017037).
文摘The 2,2,6,6-tetramethylpiperidine-1-oxyl(TEMPO)oxidized cellulose film(TOCF)has been attempted to be used as a substrate in electronic and optoelectronic devices,but the changes in the TOCF properties before and after annealing treatment have usually been neglected during device fabrication.In this study,TOCF was treated in different atmospheres(air,vacuum,and N2)and at different temperatures,and the properties were investigated.The results indicate that the optical properties are slightly affected by atmosphere and temperature;only slight transmittance loss and haze increase have been observed when TOCF is exposed to an air atmosphere at temperatures of above 120℃.In contrast to the slight effects on the optical properties,cellulose degradation and a loss of film strength have been observed regardless of the atmosphere used when placed at temperatures of above 100℃.Specifically,TOCF was exposed to air,followed by N2 and vacuum atmospheres.Additional Fourier transform infrared(FT-IR)and nuclear magnetic resonance(NMR)results showed that increasing the temperature had no significant effect on the structure of TOCF.Therefore,the annealing temperature should be controlled at a temperature of lower than 100℃and a vacuum atmosphere is preferred.
文摘Regenerated cellulose films with water-resistance were obtained by an improved method ofpreparing cellulose cuoxam solution from pulps of agricultural wastes (linters, wheat straw, reedand Bamao). Experimental results showed that the mechanical properties of both the dry. and wetfilms were excellent. Data from IR, SEM and tensile strength measurements implied that thesignificant improvement of water-resistance of the films was due to the cohesion between the thinTung oil covers with hydrophobicity and the regenerated cellulose films. The films werecompletely biodegraded after being buried in soil for 100 days. The transmittance of the filmsderived from linter and reed in visible band range were 80-90%.
基金The work ws supported by the State Economy and Trade Commission of China.
文摘The biodegradability of Aspergillus niger (A. niger), Mucor (M-305) and Trichoderma (T-311) strains on regenerated cellulose films in media was investigated. The results showed that T-311 strain isolated from soil adhered on the cellulose film fragments has stronger degradation effect on the cellulose film than A. niger strain. The weights, molecular weights and tensile strengths of the cellulose films in both shake culture and solid media decreased with incubation time, accompanied by producing CO2 and saccharides. HPLC, IR and released CO2 analysis indicated that the biodegradation products of the regenerated cellulose films mainly contain oligosaccharides, cellobiose, glucose, arabinose, erythrose, glycerose, glycerol, ethanal, formaldehyde and organic acid, the end products were CO2 and water. After a month, the films were completely decomposed by fungi in the media at 30 degrees C.
基金support by the Universitas Negeri Malang for the PNBP research grant for PUI CAMRY with Contract No.4.3.714/UN32.14.1/LT/2020.
文摘The microstructure of bacterial cellulose nanofibers(BCNs)film affects its characteristic.One of several means to engineer the microstructure is by changing the BCNs size and fiber distribution through a high-pressure homogenizer(HPH)process.This research aimed to find out the effects of repetition cycles on HPH process towards BCNs film characteristics.To prepare BCNs films,a pellicle from the fermentation of pineapple peels waste with Acetobacter xylinum(A.xylinum)was extracted,followed by crushing the pellicle with a high-speed blender,thereafter,homogenized using HPH at 150 bar pressure with variations of 5,10,15,and 20 cycles.The BCNs films were then formed through the casting process and drying in the oven at 60°C for 8 h followed by structural,morphological,and optical properties investigation using X-ray diffraction(XRD),scanning electron microscopy(SEM)and Fourier transform infrared(FTIR)spectrometer along with BCNs films porosity,tensile and roughness test.The research showed that the effect of HPH cycle on BCNs resulted in the highest film tensile strength by 109.15 MPa with the lowest surface roughness(Ra)of 0.93±0.10μm at 10 cycles.The HPH process is effective in controlling BCNs film porosity level.The HPH cycles influence the crystalline index and crystallite size,slightly.
基金the National Natural Science Foundation of China(31972134)the Key Science&Technology Specific Projects of Anhui Province(201903b06020003)+1 种基金the Fundamental Research Funds for the Central Universities(JZ2019YYPY0027)the Funds for Huangshan Professorship of Hefei University of Technology(407-037019).
文摘Due to the increased potential for application of natural biopolymers in the food industry,the goal of this study was to prospectively produce antimicrobial films using asparagus residue.In this study,cellulose was extracted from asparagus residue,and then 3 cellulose solutions of 0.008,0.01 and 0.025 g/mL were applied to prepare films using a phase inversion process.Films were characterized by Fourier transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),thermal gravimetric analysis(TGA)and scanning electron microscopy(SEM).The film produced by 0.01 g/mL asparagus cellulose solution exhibited a swelling ratio of 125.4%and excellent antimicrobial activity against Escherichia coli and Staphylococcus aureus using the disk agar diffusion method.This study presents a promising method for producing antimicrobial films with asparagus residue.
基金This work was supported by the National Natu- ral Science Foundation of China (No. 90206002 and 90201013)the National "863" Project of China (No. 2002AA313030).
文摘SiO_2/TiO_2/methylcellulose composite materials processed by the sol-gel technique were studied for optical waveguide applications. With the help of methylcellulose, an organic binder, SiO2/TiO2/methylcellulose hybrid thick films were prepared by a single spin-coating processes. After annealing at 70 °C for an hour, 2.5-μm crack-free and dense organic-inorganic hybrid optical films with a refractive index of 1.537 were achieved. Optical losses of plane waveguide made up of those films and ordinary slide glass substrate are around 0.3 dB/cm at 650 nm. Scanning electronmicroscopy (SEM) and UV-visible spectroscopy (UV-VIS), have been used to characterize the thick films.
基金financially supported by the Major Program of National Natural Science Foundation of China(No.21334005)the National Natural Science Foundation of China(No.20874079)
文摘High strength cellulose composite films with antibacterial activities were prepared by dispersing montmorillonites （MMT） into cellulose solution in LiOH/urea aqueous solvent followed by regeneration in ethanol coagulation bath, and then by soaking in 5 wt% hexadecylpyridine bromide ethanol solutions to induce the antibacterial action. The cellulose/MMT composite films were characterized by field emission scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, FTIR, UV-spectra, wide angle X-ray diffraction and mechanical test. The results revealed that MMT was dispersed well in the cellulose matrix to form layer structure with a thickness of approximately 3 nm. The mechanical properties of the cellulose/MMT composite films were significantly improved to achieve 132 MP for tensile strength as a result of the MMT delamination. The hexadecylpyridine bromide was fixed well in the cellulose/MMT matrix through cation exchange, leading to the excellent antibacterial activities against Staphylococcus aureus and Escherichia coli, which is important in their practical applications.
