球状LaVO_4:Eu~(3+)纳米晶的水热合成及其荧光性能

以La2O3、Eu2O3、浓HNO3、氢氧化钠、Na VO3、无水乙醇、一缩二乙二醇为原料,采用聚乙烯吡咯烷酮(PVP)辅助水热法合成了La VO4:Eu3+纳米晶,并用X粉末衍射(XRD)、透射电镜(HRTEM)、红外光谱(IR)和荧光光谱(FL)对产品进行了表征和分析。测试结果表明,球状La VO4:Eu3+纳米晶在620nm处有较强的红光发射,溶液p H影响La VO4:Eu3+纳米晶的色纯度和发光强度,其中p H为5时样品的绿色纯度最好,而p H为8时的绿光发射最强。     

First experiments for the use of microblasting technique with powdered cellulose as a new tool for dry cleaning artworks on paper

This research evaluates the use of microblasting technique with powdered cellulose as a new tool for dry cleaning documents. Different cleaning tests were conducted on three documents with different properties following this new approach and the results were compared to those obtained with traditional dry cleaning with erasers. In order to assess changes caused to the supports, the treated documents were examined both before and after cleaning with optical and 3D stereomicroscopy, SEM-EDS and spectrophotometry. The results allow the conclusion that microblasting with powdered cellulose is a feasible technique to remove surface dirt or grime on paper documents. This research proves that the new use of the technique does not entail changes to the surface properties of the treated supports. Moreover, powdered cellulose is chemically stable and compatible with paper documents, preventing negative long-term effects derived from the presence of rubber residues that may remain in paper fibres when using erasers in dry cleaning treatments.     

Middle-ultraviolet laser cleaning of particulates from sized ground wood cellulose and pure cellulose paper

Ground wood cellulose paper exhibits a practicable cleaning laser fluence window during middle-UV radiation processing. In this case, a minimum dose volume density should be applied. However, cleaning of bleached cellulose paper is accompanied by strong yellowing and destruction. The presence of charcoal graphite particulates shows substantial influence on the yellowing with increasing coverage.     

一种ABS 塑料表面涂料的研制

用热塑性丙烯酸树脂, 醋酸- 丁酸纤维素(CAB) , 不同助剂等原料配制出ABS 塑料用表面涂料- 银色漆光油; 并对涂层附着机理, 溶剂的选用, 不同助剂的调配作了较为详细的叙述.     

Tert-butyl amine borane complex: An unusual application of a reducing agent on model molecules of cellulose based materials

The need to preserve cultural heritage on paper requires the setting up of methods and treatments that can be applied to original documents. The cellulose main degradation processes are hydrolysis and oxidation. Only the first one has been widely investigated. The Istituto Centrale per la Patologia del Libro (ICPL) focused its attention on oxidation phenomena and studied a particular class of reducing agents, namely the borane-amine complexes. During the investigation it was found that the borane tert-butylamine complex, besides being the most promising reducing agent, was also able to react with carboxylic functions. In the present study ¹H and ¹³C NMR, Pulsed field gradient NMR spectroscopy as well as Raman spectroscopy were used as analytical tools to disclose the mechanism of the interaction between the borane tert-butylamine complex and the carboxylic functions. Given the complexity of the paper/environment interactions and the subsequent degradation phenomena, we worked on simplified models based on small carbohydrate molecules in order to reproduce the behavior of degraded paper after reductive restoration. Modified D-glucose and D-cellobiose were used in this first step in order to set up the analytical methods before approaching more complex systems such as microcrystalline cellulose and paper. Our results give the experimental evidence that borane tert-butylamine complex is also able to neutralize acidic functions. This finding has important perspectives in paper restoration.     

The effect of dust particles on cellulose degradation

This study focuses on the changes in properties of cellulose-based paper, which can take place as a consequence of its contamination by dust particles. The PM1 (fine) and PM10 (coarse) fractions of the dust particles from archival repositories were collected on cellulose filters Whatman 41, polytetrafluorethylene, and quartz filters. The latter two types of samples were subsequently analyzed gravimetrically, with ion chromatography, PIXE, and the thermal–optical transmission method, giving mass, ionic, elemental carbon, and organic carbon concentrations. After artificial aging, the viscosity-average degree of polymerization of cellulose (DP_v) was measured. It was confirmed that cellulose-based paper can undergo substantial changes when contaminated by dust particles and artificially aged. The decrease of the DP_v of cellulose showed a negative correlation with the deposited mass of sulfate ions in the dust particles. Considering the particle size fraction, the results suggest the decisive importance of the fine (PM1) particles. The results provide better understanding of how particulate matter contributes to the chemical degradation of cellulose-based paper. Such knowledge is of importance when considering appropriate conservation measures in archives, libraries, and galleries.     

新型黄原酸酯对废水中Cd2+的吸附研究

利用柚子皮纤维素制备新型黄原酸酯(SCX),对废水中Cd2 进行吸附研究。通过对影响其吸附效果的SCX用量、Cd2 初始浓度、pH值、反应温度、吸附时间等因素进行吸附实验。结果表明:当废水中Cd2 初始浓度为15mg/L时,0.022gSCX对Cd2 去除率高达99.36%,其吸附容量达33.87mg/g,具有良好的吸附性。SCX对Cd2 的吸附符合Langmiur和Freundlich方程。     

纤维素织物生物整理工艺技术研究

本文就酶的减量原理的影响酶活度的因素等问题进行了讨论,目的在于使用者能够正确选用合适的纤维素酶和合理的工艺条件,使减量后的纤维强力下降不致过大,而柔软效果达到最佳。     

纤维素醚的研究进展

纤维素以其资源丰富、生物可降解、可再生、易改性等优点,认为是未来能源、化工的主要原料,被广泛研究,纤维素醚就是其重要的衍生物之一。文章简要综述了纤维素醚的结构特点、性能及其合成方法。     

纤维素降解过程中金属离子作用的研究

用微量量热法研究了7种金属离子及几种混合离子对纤维素酶降解纤维素反应的影响.实验结果表明,在pH=4.60,T=310K时,相同浓度的离子中Li+、Na+、K+、Ni2+、Zn2+、Co2+离子均表现出抑制作用,其中Li+抑制作用显著;Cu2+有明显的激活作用.当Li+、Na+、K+3种离子混合共同作用于反应时,表现出激活作用;当Ni2+、Cu2+、Zn2+3种离子,Co2+、Ni2+2种离子混合共同作用于反应时,表现出抑制作用.