Five Populus x euramericana wood samples representing three different sites were selected and nearinfrared （NIR） spectra were obtained. For these sections, basis weight, brightness and three mechanical properties （...Five Populus x euramericana wood samples representing three different sites were selected and nearinfrared （NIR） spectra were obtained. For these sections, basis weight, brightness and three mechanical properties （tensile index, tearing index and bursting index） were determined by standard analytical methods. Calibrations were developed for each paper property using the NIR spectra, data on paper properties, using partial least squares （PLS） regression. The results show that the coefficients of correlation of calibration and validation for basis weight were 0.8824 and 0.8299, respectively; the standard error of calibration （SEC） and prediction （SEP） were 1.150 and 1.170, respectively. In testing for brightness, the correlation coefficient of calibration was 0.9621 and for validation 0.9612, while the SEC and SEP were 0.997 and 1.300, respectively; paper brightness and NIR spectroscopy were highly correlated. NIR spectroscopy can be used to predict tensile, tearing and bursting indices of paper samples rapidly. We found that the paper properties fitted by NIR and GB methods were highly correlated. The coefficients of correlation of calibration and validation for basis weight exceeded 0.8000, while the SEC and SEP were very small. These results reveal that the five paper properties of Populus x euramericana and those predicted by the NIR model were highly correlated. We conclude that the NIR models can be used for the prediction of paper properties.展开更多
This study investigated the potential of locally sourced mushrooms as a sustainable alternative to marine-derived chitosan in papermaking.Chitosan was extracted from four local(Boletus edulis,Suillus luteus,Leccinum a...This study investigated the potential of locally sourced mushrooms as a sustainable alternative to marine-derived chitosan in papermaking.Chitosan was extracted from four local(Boletus edulis,Suillus luteus,Leccinum auran-tiacum,Suillus variegatus),one commercially available(Agaricus bisporus)and one laboratory-grown(Phanero-chaete chrysosporium)fungal species.Paper handsheets were prepared using either 100%regenerated paper or a 50/50 blend of regenerated paper and hemp fibres.2.5%chitosan(based on dry mass)was incorporated into the paper mass,using chitosan sourced from B.edulis,A.bisporus,P.chrysosporium,and crustacean chitosan.Fungal chitosan sources were selected based on multiple factors.B.edulis exhibited the highest chitosan yield(5.03%),the highest degree of deacetylation(77.0%)and the highest molecular weight(59.18 kDa).It is also a widely prevalent species in the Baltic region.A.bisporus demonstrated the highest degree of crystallinity(62.7%).Additionally,it has readily available waste material due to its popularity in the food industry.P.chysosporium,with its low degree of crystallinity(33.9%)and small molecular weight(9.06 kDa),is easily cultivable in laboratory conditions.Mechanical testing of papers showed that fungal chitosan significantly improved tensile index and elongation at break(in wet and dry states)and burst strength while reducing air permeability.Notably,fungal chitosan con-sistently outperformed crustacean chitosan.Commercially available A.bisporus and locally sourced B.edulis emerged as promising alternatives to crustacean chitosan in papermaking.Further research is needed to explore other applications for fungal chitosan.展开更多
Both Edgeworthia and Wikstroemia have been used traditionally in hand papermaking in China.As plants from the Thymelaeaceae family,these species have been mentioned periodically and have been mixed or substituted with...Both Edgeworthia and Wikstroemia have been used traditionally in hand papermaking in China.As plants from the Thymelaeaceae family,these species have been mentioned periodically and have been mixed or substituted with each other.This study reviewed their papermaking background and status,and selected one of the Edgeworthia and three of the Wikstroemia raw materials that are still in use.Pulp was cooked under the same conditions in the laboratory,and handsheets of pure and mixed materials were obtained using a Rapid-Köthen sheet former.A series of physical properties,such as color,structure,and mechanical properties were tested,followed by a comparison and discussion of the raw material properties.The results show that Wikstroemia fibers are generally thinner and shorter,but there are variations between the different genera of raw materials.Thus,compared with Edgeworthia,Wikstroemia has some advantages in tensile strength,although it shows some disadvantages when it comes to tearing strength.The performance of a mixed-ingredient paper sheet falls between the performance of two pure-component papers.For cost and performance reasons,adding a small amount of Wikstroemia(e.g.,<20%)to Edgeworthia is preferable.展开更多
ZnO thin films prepared by using quantitative filter paper as a template and Zn（CH3CO2）2.2H2O ethanol precursor solution were characterized by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The ...ZnO thin films prepared by using quantitative filter paper as a template and Zn（CH3CO2）2.2H2O ethanol precursor solution were characterized by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The effects of sample calcination temperature, precursor concentration and filter paper types were studied, and the growth process was investigated by infra-red （IR） spectroscopy and thermogravimettic analysis/differential thermal analysis （TGA/DTA）. The results show that samples soaked in a 1.5 mol/L Zn（CH3 CO2）2.2H2O ethanol solution and calcined at 600 ℃ yield ZnO films of uniform particle size, approximately 30, 40 and 50 nm. for fast-, medium- and slow-speed filter papers, respectively. The formaldehyde gas sensing properties of the ZnO nanoparticles were tested, showing that the material prepared from fast-speed filter paper has a higher response to 120-205 ppm formaldehyde at 400 ℃ than that prepared from medium- or slow-sneed paper, which depends on the narticle size.展开更多
文摘Five Populus x euramericana wood samples representing three different sites were selected and nearinfrared （NIR） spectra were obtained. For these sections, basis weight, brightness and three mechanical properties （tensile index, tearing index and bursting index） were determined by standard analytical methods. Calibrations were developed for each paper property using the NIR spectra, data on paper properties, using partial least squares （PLS） regression. The results show that the coefficients of correlation of calibration and validation for basis weight were 0.8824 and 0.8299, respectively; the standard error of calibration （SEC） and prediction （SEP） were 1.150 and 1.170, respectively. In testing for brightness, the correlation coefficient of calibration was 0.9621 and for validation 0.9612, while the SEC and SEP were 0.997 and 1.300, respectively; paper brightness and NIR spectroscopy were highly correlated. NIR spectroscopy can be used to predict tensile, tearing and bursting indices of paper samples rapidly. We found that the paper properties fitted by NIR and GB methods were highly correlated. The coefficients of correlation of calibration and validation for basis weight exceeded 0.8000, while the SEC and SEP were very small. These results reveal that the five paper properties of Populus x euramericana and those predicted by the NIR model were highly correlated. We conclude that the NIR models can be used for the prediction of paper properties.
基金funded by the Latvian Council of Science Project No.lzp-2023/1-0123“Development of Biopolymer-Based Hydrophobic Multi-Layer Packaging Material from Biomass Waste Streams”。
文摘This study investigated the potential of locally sourced mushrooms as a sustainable alternative to marine-derived chitosan in papermaking.Chitosan was extracted from four local(Boletus edulis,Suillus luteus,Leccinum auran-tiacum,Suillus variegatus),one commercially available(Agaricus bisporus)and one laboratory-grown(Phanero-chaete chrysosporium)fungal species.Paper handsheets were prepared using either 100%regenerated paper or a 50/50 blend of regenerated paper and hemp fibres.2.5%chitosan(based on dry mass)was incorporated into the paper mass,using chitosan sourced from B.edulis,A.bisporus,P.chrysosporium,and crustacean chitosan.Fungal chitosan sources were selected based on multiple factors.B.edulis exhibited the highest chitosan yield(5.03%),the highest degree of deacetylation(77.0%)and the highest molecular weight(59.18 kDa).It is also a widely prevalent species in the Baltic region.A.bisporus demonstrated the highest degree of crystallinity(62.7%).Additionally,it has readily available waste material due to its popularity in the food industry.P.chysosporium,with its low degree of crystallinity(33.9%)and small molecular weight(9.06 kDa),is easily cultivable in laboratory conditions.Mechanical testing of papers showed that fungal chitosan significantly improved tensile index and elongation at break(in wet and dry states)and burst strength while reducing air permeability.Notably,fungal chitosan con-sistently outperformed crustacean chitosan.Commercially available A.bisporus and locally sourced B.edulis emerged as promising alternatives to crustacean chitosan in papermaking.Further research is needed to explore other applications for fungal chitosan.
基金supported by the National Key R&D Program of China(2019YFC1520300).
文摘Both Edgeworthia and Wikstroemia have been used traditionally in hand papermaking in China.As plants from the Thymelaeaceae family,these species have been mentioned periodically and have been mixed or substituted with each other.This study reviewed their papermaking background and status,and selected one of the Edgeworthia and three of the Wikstroemia raw materials that are still in use.Pulp was cooked under the same conditions in the laboratory,and handsheets of pure and mixed materials were obtained using a Rapid-Köthen sheet former.A series of physical properties,such as color,structure,and mechanical properties were tested,followed by a comparison and discussion of the raw material properties.The results show that Wikstroemia fibers are generally thinner and shorter,but there are variations between the different genera of raw materials.Thus,compared with Edgeworthia,Wikstroemia has some advantages in tensile strength,although it shows some disadvantages when it comes to tearing strength.The performance of a mixed-ingredient paper sheet falls between the performance of two pure-component papers.For cost and performance reasons,adding a small amount of Wikstroemia(e.g.,<20%)to Edgeworthia is preferable.
基金National 863 Program (No. 2007AA061401) for financial support
文摘ZnO thin films prepared by using quantitative filter paper as a template and Zn（CH3CO2）2.2H2O ethanol precursor solution were characterized by scanning electron microscopy （SEM） and X-ray diffraction （XRD）. The effects of sample calcination temperature, precursor concentration and filter paper types were studied, and the growth process was investigated by infra-red （IR） spectroscopy and thermogravimettic analysis/differential thermal analysis （TGA/DTA）. The results show that samples soaked in a 1.5 mol/L Zn（CH3 CO2）2.2H2O ethanol solution and calcined at 600 ℃ yield ZnO films of uniform particle size, approximately 30, 40 and 50 nm. for fast-, medium- and slow-speed filter papers, respectively. The formaldehyde gas sensing properties of the ZnO nanoparticles were tested, showing that the material prepared from fast-speed filter paper has a higher response to 120-205 ppm formaldehyde at 400 ℃ than that prepared from medium- or slow-sneed paper, which depends on the narticle size.
