The semi-carbonization method is a kind of waste treatment to carbonize rice straw fiber at low semi-carbon temperature. The rice straw fiber is carbonized incompletely, which serves as building materials additive. Th...The semi-carbonization method is a kind of waste treatment to carbonize rice straw fiber at low semi-carbon temperature. The rice straw fiber is carbonized incompletely, which serves as building materials additive. The results reveal that the optimized carbonization condition is at 313 ℃ for 20-40 min with H3PO4 as activator. The structure of semi-carbonized straw fiber displays a large quantity of micropores, with which the wall thickness and the pore diameter are in the range of 1-4 μm, presenting the iodine sorption value of 1 320-1 470 mL/g and the methylene blue sorption value of 1 330-1 460 mg/g, respectively. Moreover, the acidic oxygen-containing groups impart the structure higher sorption of polar molecules. The semi-carbonized rice straw fiber with open and closed micro-mesopores demonstrates good hygroscopicity, implying the potential application as a functional additive in building materials.展开更多
The silicification of rice straw is a factor that affects the grain production and straw nutritive quality. The procedure of chemical analysis for silicon in straw is, however, time and labor consuming, and slightly p...The silicification of rice straw is a factor that affects the grain production and straw nutritive quality. The procedure of chemical analysis for silicon in straw is, however, time and labor consuming, and slightly poor in accuracy. The study has attempted to apply near infrared reflectance spectroscopy (NIRS) technique as an advanced alternative to predict the fiber composition and silicification in rice straw. Ninety-two samples from different seasons and varieties were collected over the Fujian Province. Their chemical analyses were carried on the aspects of hemicellulose, cellulose, lignin, extractable and non-extractable silicon, and the results were used as a database for NIRS analyses. The prediction model was developed through modified partial least square regression (MPLS) for a calibration program. The factors that may affect the calibration, cross-validation and the prediction for the application of NIRS on rice straw were also discussed.展开更多
Straw fiber-reinforced cement board made from straw fiber and cement was prepared by semi-dry processing technology to investigate the effects of alkali treatment on the mechanical properties of the board.The results ...Straw fiber-reinforced cement board made from straw fiber and cement was prepared by semi-dry processing technology to investigate the effects of alkali treatment on the mechanical properties of the board.The results indicate that the board fibers were treated with 1%alkali solution showed obvious improvements in mechanical properties.After alkali treatment,hemi-celluloses of straw fiber were hydrolyzed and dissolved,which avoided hemi-celluloses hydrolyzing into monosaccharide to hinder the solidifying of cement. The fibers surface became rough,which increased the mechanical interweaving force between cement and fibers.Thereby the board’s mechanical properties were improved.At the same time,the increase of tensile strength and aspect ratio of the fibers improved the mechanical properties.展开更多
基金Funded by Key Projects of the National Science&Technology Pillar Program(No.2013BAC13B01)Independent Research of State Key Laboratory of Silicate Materials for Architectures
文摘The semi-carbonization method is a kind of waste treatment to carbonize rice straw fiber at low semi-carbon temperature. The rice straw fiber is carbonized incompletely, which serves as building materials additive. The results reveal that the optimized carbonization condition is at 313 ℃ for 20-40 min with H3PO4 as activator. The structure of semi-carbonized straw fiber displays a large quantity of micropores, with which the wall thickness and the pore diameter are in the range of 1-4 μm, presenting the iodine sorption value of 1 320-1 470 mL/g and the methylene blue sorption value of 1 330-1 460 mg/g, respectively. Moreover, the acidic oxygen-containing groups impart the structure higher sorption of polar molecules. The semi-carbonized rice straw fiber with open and closed micro-mesopores demonstrates good hygroscopicity, implying the potential application as a functional additive in building materials.
文摘The silicification of rice straw is a factor that affects the grain production and straw nutritive quality. The procedure of chemical analysis for silicon in straw is, however, time and labor consuming, and slightly poor in accuracy. The study has attempted to apply near infrared reflectance spectroscopy (NIRS) technique as an advanced alternative to predict the fiber composition and silicification in rice straw. Ninety-two samples from different seasons and varieties were collected over the Fujian Province. Their chemical analyses were carried on the aspects of hemicellulose, cellulose, lignin, extractable and non-extractable silicon, and the results were used as a database for NIRS analyses. The prediction model was developed through modified partial least square regression (MPLS) for a calibration program. The factors that may affect the calibration, cross-validation and the prediction for the application of NIRS on rice straw were also discussed.
文摘Straw fiber-reinforced cement board made from straw fiber and cement was prepared by semi-dry processing technology to investigate the effects of alkali treatment on the mechanical properties of the board.The results indicate that the board fibers were treated with 1%alkali solution showed obvious improvements in mechanical properties.After alkali treatment,hemi-celluloses of straw fiber were hydrolyzed and dissolved,which avoided hemi-celluloses hydrolyzing into monosaccharide to hinder the solidifying of cement. The fibers surface became rough,which increased the mechanical interweaving force between cement and fibers.Thereby the board’s mechanical properties were improved.At the same time,the increase of tensile strength and aspect ratio of the fibers improved the mechanical properties.
