聚砜膜的表面亲水改性

配制叔丁基过氧化氢(TBHP)-多巴胺(DA)-三羟甲基氨基甲烷(Tris)缓冲液,通过在聚砜(PSf)膜表面沉积聚多巴胺(PDA)来制备亲水纳滤膜.研究了TBHP不同添加量以及不同pH时改性膜的亲水性能,并利用FTIR、XPS、水油接触角测量仪、SEM、AFM等方法表征改性前后PSf膜表面的元素组成、结构、形貌、亲水性能、稳定性以及渗透性能.结果表明,pH=8.5、TBHP添加量为800μL时,PSf膜的水接触角由52°降到13°,油接触角由142°升到165°,得到了亲水疏油改性膜,纯水通量为91.3 L/(m~2·h),相比PSf基膜提高了170.4%,截留率达90.7%,超声振荡后,水接触角仅下降3.1°,表现出良好的稳定性.     

紫外辐照改性聚丙烯纤维固定化溶菌酶的研究

在聚丙烯纤维紫外光照法接枝甲基丙烯酸甲酯(MMA)的基础上,通过酰胺化反应将改性纤维表面官能团转换为胺基后进行溶菌酶固定化,实现聚丙烯纤维的酶法功能化改性.通过对比不同处理条件下纤维的红外光谱(FT-IR)和扫描电镜(SEM),可以看出MMA已经成功接枝到聚丙烯纤维上,并且将溶菌酶固定在了纤维上.另外,还考察了MMA接枝率对纤维表面胺基密度和固定化溶菌酶酶活的影响.结果表明,纤维上的胺基密度随改性效果的提高而增大,当接枝率为1.69%时,固定化的溶菌酶酶活达到最大值为18U/cm2.     

脱硫用PVDF膜的结构调控与性能研究

以聚偏氟乙烯(PVDF)为膜材料,二甲基乙酰胺(DMAc)为溶剂,采用浸没沉淀相转化法制膜,研究了亲/疏水性的添加剂对PVDF膜结构、接触角及气通量的影响;采用含氟表面活性剂 Zonyl 8740对PVDF膜进行疏水改性,通过ATR-FTIR、FE-SEM、接触角等对膜表征,并进行脱硫性能评价.结果表明,疏水性添加剂使PVDF膜表面水接触角提高,添加剂种类对膜气通量有明显影响,在20℃、0.01 MPa实验条件下,PVDF膜最大气通量为85.6 m3/(m2·h),Zonyl 8740涂覆改性后PVDF膜表面疏水性提高,水接触角可达到133.5°,二氧化硫脱除率可达到81.3％.     

氧化剂高碘酸钠诱发多巴胺自聚合在MBfR膜表面改性中的应用

针对膜生物膜反应器(Membrane Biofilm Reactor,MBfR)研究中疏水性微孔膜氧传质性能不佳等问题,采用自聚合法(多巴胺为单体)对自制疏水性聚偏氟乙烯(PVDF)中空纤维膜进行表面改性,并选用高碘酸钠(Sodium Periodate,SP)为氧化剂,研究氧化剂SP投加对于多巴胺自聚合过程、改性膜性能及稳定性的影响.研究结果表明,与未投加SP相比,投加SP能够通过加速多巴胺的自聚合及聚多巴胺在膜表面的沉积,大大缩短多巴胺表面改性时间(自24h降至6h),同时获得适用于MBfR技术的机械性能、亲水性能、氧传质性能良好的多巴胺改性膜,改性膜接触角自原膜76.5°降低至33.4°,氧总转移系数自原膜0.78×10~(-2) min~(-1)提高为1.58×10~(-2) min~(-1)(原膜的2.03倍).此外SP的投加还可以提高改性膜在极性溶液、强酸、强碱中的稳定性,投加SP改性膜在丙酮、0.1mol/L HCl及0.1mol/L NaOH中的稳定性较未投加SP改性膜分别提高了96.5%,85.1%与48.8%.     

双氨基有机硅后交联聚丙烯酸改性PTFE平板膜及其分离性能研究

通过聚丙烯酸(PAA)与双氨基有机硅9300的后交联反应对聚四氟乙烯(PTFE)平板膜进行亲水改性,并将其用于水晶研磨废水的处理.研究双氨基有机硅浓度、PAA/9300质量比、反应温度及时间等参数对PTFE平板膜形貌、表面化学结构、亲水性及分离性能的影响.结果表明,膜纤维变得比较光滑且有少量颗粒出现,改性膜表面和截面出现N、O和Si元素,膜表面出现羧基、氨基等亲水基团,改性后的PTFE膜表面接触角由136°±2.1°降低到30.35°±1.3°,水晶碾磨废水浊度去除率达到99.91%,改性膜有很好的抑制蛋白质吸附污染的性能.     

耐氯聚酰胺复合纳滤膜的制备与性能

采用哌嗪(PIP)与均苯三甲酰氯(TMC)为单体以界面聚合制备聚酰胺复合纳滤膜,用戊二醛(GA)对聚酰胺复合纳滤膜进行交联处理,再浸入间氨基乙酰苯胺中进行接枝反应得到具有耐氯性的改性复合纳滤膜.通过红外光谱和固体表面电位Zeta电位分析仪表征,证明间氨基乙酰苯胺接枝到活性层表面,降低了复合膜的荷负电性,扫描电子显微镜显示改性膜呈现无孔和更加粗糙的状态,接触角测量表明改性提高了复合膜表面的亲水性.耐氯测试表明,室温下,在pH=4,浓度1 g/L的NaClO溶液中浸泡10 h后,改性膜的截留率由94.04％下降至91.81％,PIP-TMC复合纳滤膜的截留率由94.60％下降至78.85％.     

漆酶催化麻织物固定化溶菌酶及其抗菌性能

利用漆酶对木质素的催化作用将溶菌酶接枝到富含木质素的麻织物上,赋予其抗菌性。通过考马斯亮蓝染色法证明了溶菌酶的接枝,对两种不同木质素含量的织物(棉/亚麻混纺织物、黄麻织物)的接枝效果进行了比较,并应用扫描电镜(SEM)考察了接枝后麻纤维表面形态,研究了溶菌酶固定化后麻织物的抗菌性能和耐洗稳定性。结果表明,麻织物经漆酶催化可实现溶菌酶的固定化,麻纤维木质素含量越高,溶菌酶接枝越多,整理后棉/亚麻织物和黄麻织物抑菌率分别达到60.38%和72.87%,且通过接枝法固定溶菌酶的麻织物较吸附固定法具有更好的耐水洗稳定性和抗菌效果。     

“一步法”构建基于Zn2+的抗菌表面

不依赖于抗生素的抗菌表面是生物材料及器械设计领域的重要研究内容，可以避免耐药性细菌问题。现有材料表面抗菌策略仍然存在步骤较为繁琐、反应条件过于苛刻等不足，因此，本研究以多巴胺和硫酸锌(ZnSO₄)为原料，在常温、水相条件下采用“一步法”构建广谱性含锌聚多巴胺抗菌涂层(PDA@Zn)。水接触角、涂层厚度和X光电子能谱等结果证实PDA@Zn涂层成功构建。涂层中的锌以Zn²⁺的形式与PDA中邻苯二酚官能团配位结合;涂层的表面Zn²⁺密度可以通过改变ZnSO₄投料的浓度来调控。抗菌实验的结果表明ZnSO₄投料浓度为1 mg/m L时所构建的PDA@Zn涂层(PDA@Zn/1)具有优异的杀菌效果，对大肠杆菌和表皮葡萄球菌的抗菌率分别为99.7%和99.3%。体外细胞培养试验结果表明，PDA@Zn/1涂层上L929的24 h和72 h相对增殖率分别为63.63%及48.32%，具有一定的细胞毒性。该方法提供了一种高效、简单的表面抗菌策略，但该策略的生物相容性还有待进一步提升。     

K_2S_2O_8-Na_2S_2O_3引发苯乙烯磺酸钠接枝阴离子交换膜改性

通过K_2S_2O_8-Na_2S_2O_3氧化还原体系引发苯乙烯磺酸钠(SSS)接枝阴离子交换膜,用衰减全反射傅里叶变换红外光谱(ATR-FTIR)、扫描电子显微镜(SEM)、原子力显微镜(AFM)和接触角测量仪等对阴离子交换膜改性前后进行性质表征,并以十二烷基苯磺酸钠(SDBS)作为模型污染物进行污染实验,考察改性膜的抗污染性能及其稳定性.结果表明,SSS接枝后可有效改善阴离子交换膜表面的亲水性和负电荷密度,改性膜接触角由72°变为60°,表面电荷密度由0.92 mV变为-7.85 mV,表明带负电荷的磺酸基团被成功接枝到阴膜表面.通过探究改性条件对改性膜性质的影响发现,当改性温度为35℃、单体质量浓度为1.0 g/L、接枝时间为10 min时改性效果最佳.该改性条件下获得的SSS修饰阴离子交换膜抗污染能力明显提高,稳定性良好且不影响其脱盐性能.     

远程氩等离子体对聚偏氟乙烯超滤膜的表面改性

利用朗缪尔探针和发射光谱法诊断远程氩等离子体,确定了离子密度和活性粒子的分布规律,以预测最佳改性区域;采用远程氩等离子体改性聚偏氟乙烯(PVDF)超滤膜,设计正交实验探究远程氩等离子体处理改性效果的最优工艺组合,并通过水接触角表征超滤膜改性前后的亲水性能;利用扫描电镜和X射线光电子能谱表征膜表面的形貌和化学成分变化,并通过拉伸性能测试表征改性后PVDF超滤膜强度。最后,通过海藻酸钠(SA)过滤实验评价膜改性前后过滤性能及抗污染性能。实验结果表明,远程氩等离子体改性的最优条件为,射频功率90 W、处理时间90 s、压强20 Pa、距放电中心40 cm处;PVDF超滤膜表面通过远程氩等离子改性后,其表面通过引入含氧、含氮基团提高了其表面亲水性能,水接触角从95.63°降至62.19°,且改性后的PVDF超滤膜最大拉伸强度由403.11 gf/cm~2增至为439.37 gf/cm~2。通过SA过滤实验,改性后的PVDF超滤膜具有良好的过滤性能和抗污染性能,其水通量和SA通量分别从123.36 L/(m~2·h),49.08 L/(m~2·h)增至151.98 L/(m~2·h),68.10 L/(m~2·h),截留率从77.35%增至87.25%,总污染率从72.50%降至60.20%。     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Synthesis of Alumina-Zirconia Nanocomposites by Solgel Process

Al₂O₃-ZrO₂ nanocomposites were developed starting with the solgel process. Composite alumina-zirconia nanopowders were synthesized from metallorganic precursors (Aluminium secondary butoxide and zirconium Iso propoxide) using the solgel process. The parameters affecting the synthesis—solvent, concentration of precursor, R/H ratio (i.e., dilution of water in solvent)—were varied as also the temperature and pH. BET and TEM were used to measure nanosize. Diffuse reflectance spectroscopy and also qualitative optical absorption led to identical particle size estimate. The variation of process parameters was used to study the effect and interdependence of process parameters. Artificial Neural Networks was used to rigorously analyze the process. Although this led to confirmation of interdependence of parameters, the presence of a single overwhelming solvent variable was also established. Then the optimal process was used to synthesize more nanopowder. To produce bulk nanocomposite the nanopowders were sintered by varying the temperature and time period. The sintered lithoids were probed with a vickers hardness tester to measure elastic modulus, hardness, and fracture toughness. The results showed high elastic modulus, modest hardness, and very high fracture toughness.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Friction Stir Processing Strategies for Uniform Distribution of Reinforcement in a Surface Composite

Friction stir processing (FSP) is an important technique for preparing surface composites. Fabricating defect-free surface composites with uniform particle distribution by FSP is a challenging task. In this study, silicon carbide particles reinforced AA5083 alloy surface composites was fabricated using different FSP strategies including variation in process parameters, dual-tool processing and tool offset overlapping. Material flow of the processed material with reinforcement particles demonstrated that the distribution of particles was influenced by the stirring action of the probe as well as the extrusion of the plasticized material due to the movement of the tool. Process parameters, particularly rotational speed, showed a dominant influence on the distribution of silicon carbide particles.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.