APPITA 2018年第2期中英文摘要

正The strength properties of paper made from bamboo fibres under the treatment of ZnCl_2 aqueous solution XINLI TIAN WEICHENG LISUMMARY:In this work,paper made from bleached baruboo chemical pulp was treated in ZnCl_2 aqueous solution to prepare high strength paper.The effects of ZnCl_2 mass ratio,soaking time,treatment temperature,treatment time and washing time were evaluated through single factor experiments.The micro-properties of the untreated and treated paper     

Preparation and properties of high-flux and hydrophilic polysulfone superfine fibrous membrane北大核心CSCD

In this paper, the effects of volume percent of glutaraldehyde in chitosan solution on porous structure, hydrophily, mechanical properties and pure water flux of PSF superfine fibrous membrane which was pretreated by oxygen plasma, and then padded with cross-linked chitosan solution. Results show that the pore size decreases obviously, but the hydrophilicity and pure water flux improve significantly after the treatment. The optimum volume percent of glutaraldehyde is 0.40%. In this condition, the treated membrane still has high porous structure, and the average pore diameter is 2. 62 μm. The mechanical properties improve obviously. The membranes also change from hydrophobic property into hydrophilic property. The pure water flux is (1 624. 7±189.5) L/(m2 • h). © 2017 China Silk Association. All rights reserved.     

Preparation of High-precision Electrospun Nanoair Filter Paper for Air Purification

Electrospinning technology has become a research hotspot because of its advantages, such as simple operation, low cost, large specific surface area, high porosity, and good fiber continuity. Here, a new type of composite nanoair filter paper was prepared using electrospinning technology. To improve the practicability of air filter base paper, phenolic resin was used as a curing agent to improve the strength. The results show that the electrospun nanoair filter paper with air filter paper as the receiving substrate and polyvinyl alcohol (PVA) solution as the spinning solution excellently performed in all aspects. The influence of the thickness (spinning time) of the PVA nanofiber membrane on the micromorphology, physical properties, and filtration performance of the electrospun nanoair filter paper was analyzed. According to the ISO 5011-2014 standard, the initial resistance, filtration efficiency, mean pore size, and dust capacity of the electrospun nanoair filter paper were 77.3 Pa, 99.9941%, 3.50 μm, and 146 g/m², respectively, when the spinning time was 15 min.     

Homogeneous Synthesis and Characteri-zation of Quaternized Cellulose Derivatives in NaOH-urea Aqueous Solutions

Quaternized cellulose( QC) derivatives were synthesized by reacting cellulose with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride( CHPTAC) in an aqueous solution of Na OH-urea. The chemical structures and physical properties of the obtained QC derivatives were characterized using nitrogen content analysis,Fourier transform infrared spectroscopy( FT-IR),~1H-nuclear magnetic resonance(1H-NMR),X-ray diffraction( XRD),and thermal gravity analysis( TGA). The FT-IR and ~1H-NMR results confirmed the successful introduction of cationic quaternary ammonium groups into the main chain of cellulose. A series of QC derivatives with the degree of substitution( DS) values ranging from 0. 33 to 0. 80 were derived by adjusting the molar ratio of CHPTAC to anhydroglucose unit( AGU) of cellulose,concentration of cellulose in the Na OH-urea solution,as well as reaction temperature and time. According to the DS values of the QC derivatives,the optimized synthetic conditions were as follows: 25℃ reaction temperature,3% cellulose in Na OH-urea solution,the molar ratio of etherification agent to glycosidic cellulose of 15∶ 1,and 12 h reaction time. The TGA and XRD results revealed that the crystalline structure was destroyed during etherification,and the thermal stability of the QC derivatives was lower than that of cellulose.     

Mechanism Analysis of Stiffness Improvement by Waterborne Epoxy Resin Surface Sizing Agent

Low-basis-weight paper lacks normal strength and stiffness.Waterborne epoxy resin could be employed with oxidized starch to improve paper stiffness through surface sizing.In this study,the mechanism of enhancing stiffness by adding waterborne epoxy resin was fully investigated.The results indicated that through surface sizing with epoxy resin,the paper thickness was preserved,whereas the elastic modulus increased significantly and the epoxy resin had positive impact on single fiber strength.A rigid resin layer and interpenetrating polymer network formed on the surface and in the inner layer of the paper,respectively.The formed resin layer and interpenetrating polymer network strongly supported the paper,leading to the improvement of the elastic modulus and stiffness.The stiffness improvement through surface sizing was mainly due to the formation of a fibrous composite layer and penetration of the sizing agent into the inner layers of the paper.The better the combination between fiber and sizing agent,the higher were the elastic modulus and the stiffness of the whole paper.     

Changes Promote Development

正The world is changing,the environment is changing,and the paper industry is also changing.Since Cai Lun of ancient China invented the papermaking technology,paper products made from renewable plant fibers have been widely used for books,prints,packaging and functional materials,etc.These paper products also play an important role in cultural communication and life consumption.With the development of science     

淀粉-脂肪酸改性高岭土的制备及其在包装纸上的应用

To improve the bondability between clay filler and lignocellulosic fiber,Kaolin clay particles were modified using a starch-fatty acid complex method.The coating efficiency of starch on clay particle surfaces was investigated by measuring the dissolved starch in the supernatant.The experimental results indicated that more than 98%of the applied starch was precipitated onto the surface of the filler,and the resulting starch-fatty acid-clay composites had relatively good resistance against moderate shear force.The morphology,particle size,andζpotential of the starch modified filler were also determined with scanning electron microscopy,Malvern particle size analyzer,and Malvern Zetasizer,respectively.An aqueous slurry of linerboard pulp containing 5～15wt%modified fillers was used for handsheet preparation,and the effects of the addition of modified filler on the paper properties were studied.At a dosage of 10%of the modified filler(based on filler), the retention of the filler was higher than 75%.The strength properties of paper with starch modified fillers were improved by approximately 15%when compared against those of paper with unmodified fillers.     

Surface Modification and Characterization of PET Fibers

Improvement in synthetic fiber based composites is a hot topic in the material area.The incompatibility between the surfaces of synthetic fibers is a significant challenge due to fibers hydrophobic property.In this study,PET(polyethylene terephthalate) fibers based on low hydrophilic were slightly treated with NaOH or sodium dodecyl benzene sulfonate(SDBS).SEM images showed that there were some pits on the surface of PET fibers treated by NaOH,while PET fibers treated by SDBS became smoother.The peaks at 3725 cm~(-1) and 3628 cm~(-1) were generated for PET fibers treated by NaOH,which was attributed to—OH produced from the ester group hydrolysis,but no same peak is shown for the treated ones by SDBS.Meanwhile,the crystallinity indices of the treated PET fibers slightly decreased.Compared with original PET fibers,the formation of sheet made from PET fibers treated by NaOH became worse,but that from SDBS treated PET fibers became better.     

Influence of Solvent Polarity and Conditions on Extraction of Antioxidant,Flavonoids and Phenolic Content from A verrhoa bilimbi

This paper presents the influence of solvent polarity and extraction conditions on the extraction of total flavonoid, total phenolic and antioxidants from Averrhoa bilimbi. The experiment was performed using a different solvent at different extraction conditions, including extraction time （15-240 min）, temperature （30-70 ℃） and agitation speed （50-300 rpm）. Results showed that yields of extraction varies with solvent polarity. Extraction using 50% aqueous methanol gives the highest antioxidant activity and flavonoid content. The highest total flavonoid content （193.3 μg quercetin equivalent/g dry weight）, total phenolic content （717.8 μg gallic acid equivalent/g dry weight） and antioxidant activity （77%） was achieved using 50% methanol, at 70 ℃ and agitation speed of 300 rpm. This work may be useful for obtaining higher bioactive compounds during the extraction process of A. bilimbi.     

Wet Oxidation Pretreatment of Poplar Waste for Enhancing Enzymatic Hydrolysis Efficiency

In this paper, we described the optimization of the wet oxidation pretreatment conditions to enhance enzymatic hydrolysis efficiency, using poplar waste from the stock section of a paper mill as the raw material. We showed that the optimal conditions of the pretreatment for poplar waste were an initial p H value of 10, a temperature of 195℃, a holding time of 15 min, and an oxygen pressure of 1.2 MPa. In this case, the yield of the obtained solid material produced by the process was 51.7% and the reducing sugar yield was 46.8%. The solid part obtained from the pretreatment process was hydrolyzed by cellulase L-10. The optimal enzymatic conditions were a temperature of 49℃, a duration time of 56 h, an enzyme dosage of 38 FPU/g at a p H value of 4.8, and a solid-to-liquor ratio of 1∶50. The resulting cellulose conversion rate reached 96.4% in terms of the pretreated substances. In addition, a chemical composition analysis of the poplar waste and pretreated material indicated that about 92% of the hemicelluloses and 43% of the lignin in the raw material were degraded and dissolved. In addition, the crystallization decreased from 57.5% to 54.8%. An obvious fibrillation of the fiber pretreated by the wet oxidization process was observed by SEM. Moreover, high-performance liquid chromatography(HPLC) results showed a high xylose content and monosaccharide degradation products in the pretreatment solution. In conclusion, the wet oxidation pretreatment process could efficiently degrade or remove the lignin and hemicellulose, as well as reduce the crystallinity of the lignocellulosic material, which resulted in animprovement of the enzymatic ability and an increase in the cellulose conversion rate.     

基于嗅觉可视化技术的猪肉新鲜度检测

嗅觉可视化技术是使非可见物质成像（主要是气体成像）的一种无损检测新技术,属人工嗅觉模拟技术的一个新分支.使用卟啉和pH指示剂作为嗅觉可视化传感器阵列的气敏材料,检测猪肉中的优势致腐菌和新鲜度.将3种优势致腐菌-梭状芽孢杆菌、热死环丝菌、假单胞菌-分别接种至3组猪肉样本中,在3种温度--16℃,.4℃和20℃-条件下分别贮藏不同的时间后,采用扫描仪获取可视化传感器阵列与每个样本反应前后的图像信息;将阵列反应前后的颜色差值作为样本特征值,对不同的猪肉样本经不同贮藏时间后产生的挥发性气味,可视化传感器阵列显示其特定的颜色图像与其对应.结果表明,嗅觉可视化技术可以用于检测猪肉的优势致腐菌以及判断猪肉的新鲜度.     

畜禽饲养对动物源性产品质量安全的影响与防控对策

较详细地阐述了畜禽饲养环节对动物源性产品质量安全影响因素的来源,并根据分析的影响因素,针对性地提出了解决畜禽饲养环节动物源性产品质量安全的防控对策和思路.     

Prof. Dr. Dr. h. c. Dr. h. c. Bruno Huber

Ohne Zusammenfassung     

Prof. Dr.-Ing. Dr. h. c. Franz Kollmann Zum 65. Geburtstag

Ohne Zusammenfassung