PEG/GO/TiO2纳米复合材料改性PVDF膜的制备及其抗污性能

为改善聚偏氟乙烯(PVDF)膜的抗污性能,以聚乙二醇2000接枝的GO/TiO₂(PEG/GO/TiO₂)纳米复合材料为添加剂,通过非溶剂诱导沉淀相分离法制备了一系列PEG/GO/TiO₂/PVDF复合超滤膜。采用FTIR、SEM和接触角测试仪对其结构和形貌进行了表征,采用超滤法评价其纯水通量和抗污性能。结果表明,当PEG/GO/TiO₂纳米复合材料质量分数为0.60%时,制备的PEG/GO/TiO₂/PVDF复合超滤膜(记为0.60%PEG/GO/TiO₂/PVDF)表现出最佳的亲水性和抗污性能,其接触角比PVDF膜下降8.2°,总孔隙率增加13.40%,PEG/GO/TiO₂纳米复合材料在PVDF膜中分散较均匀。在0.08 MPa的工作压力下,0.60%PEG/GO/TiO₂/PVDF的纯水通量高达282.44 L/(m²·h),对腐植酸溶液的过滤通量为131.96 L/(m^2...     

十二胺浮选脱硫副产物亚硫酸镁实验及其机理研究

以镁法烟气脱硫技术产生的脱硫副产物亚硫酸镁为研究对象,采用一粗一精浮选的方法,分析副产物粒度、十二胺捕收剂和水玻璃调整剂用量等因素对脱硫副产物中亚硫酸镁浮选的影响,通过红外光谱及Zeta电位探究十二胺与脱硫副产物中亚硫酸镁的作用机理。结果表明,最佳的浮选条件为副产物粒径<0.074 mm的粒子质量分数为82.8%、粗选捕收剂十二胺用量为120 g/t、水玻璃用量为150 g/t、精选药剂的量为粗选的20%,脱硫副产物精矿中亚硫酸镁（以氧化镁质量分数计）品位达35.78%,回收率达56.8%。红外光谱及Zeta电位分析表明,十二胺与亚硫酸镁的作用原理主要以静电力吸附为主,并伴随着微弱的化学吸附作用。     

Enhanced flame retardancy,smoke suppression,and acid resistance of polypropylene/magnesium hydroxide composite by expandable graphite and microencapsulated red phosphorus

Low flame retardant efficiency and poor acid resistance of filled polymer composites are two main drawbacks of magnesium hydroxide (MH) as a flame retardant (FR). To solve these problems, expandable graphite (EG) and microencapsulated red phosphorus (MRP) were introduced into polypropylene/magnesium hydroxide (PP/MH) composite by melt compounding. The obtained PP/MH/EG/MRP quadruple composite was studied regarding its fire behavior as well as acid resistance. Obvious flame retardant synergism among MH, EG, and MRP is found in PP, which diminishes the loading of FR from 63.0 to 37.5 wt% to obtain V-0 rating in UL-94 test and low smoke release. Compact intumescent char with high thermo-oxidative stability was generated on composite surface, which plays a vital role in flame retardancy. The removal of MH by acid erosion on PP/MH/EG/MRP composite surface does not affect production of intumescent char and fire behavior of this composite. The composite displays good fire retardancy, smoke inhibition, and acid resistivity concurrently. This article renders an easy and cheap route to overcome the main faults of MH.     

Mg(OH)2阻燃剂的应用与研究进展

文章从各种阻燃剂的比较入手,在表面改性、聚合物混溶剂、复合阻燃剂几方面综述了Mg(OH)2阻燃剂的应用与研究进展,并对今后Mg(OH)2阻燃剂研究的发展前景提出了自己的观点.     

超薄、连续PVDF铁电薄膜的制备与表征

为了改善旋涂法制备纳米级超薄PVDF铁电薄膜的致密性和连续性,研究基体的表面处理对PVDF成膜性的影响,进行了对基体表面处理、改变PVDF溶剂成分、旋涂后的退火温度等对超薄PVDF铁电薄膜的连续性、表面形貌及其成分结构的影响研究。研究对硅和玻璃基底表面处理,紫外(UV)和氧等离子体辐照,改变基底的表面能后PVDF在基底上铺展特性。薄膜的表面形貌通过KEYENCE VHX-600超景深三维视频显微镜、扫描电子显微镜(SEM)和原子力显微镜(AFM)观察,采用傅里叶变换红外光谱(FTIR)和X射线衍射(XRD)对薄膜结构进行表征。结果表明:基底经过氧等离子处理可使质量分数为0.2%的PVDF溶液在硅和玻璃基体上形成超薄、连续的PVDF铁电薄膜。     

Mg-8Zn-4Al合金的化学镀镍

对Mg-8Zn-4Al合金上直接进行化学镀镍进行了研究，运用X射线粉末衍射仪、扫描电镜、金相显微镜和M532腐蚀电化学测量系统等分析了Mg-8Zn-4Al合金的组织特点和镀层的表面形貌及性能特征．结果表明：基体为α(Mg)，白色相为ψ(Al2Mg5Zn2)和τ(Mg32(Al，Zn)49)三元相，黑灰色相为共晶α(Mg)．镀层厚度约为30μm，镀镍前后的Econ由-1．55V升高到-0．4V，表明镀层平整、致密，与基体结合牢固，可有效保护Mg-8Zn-4Al合金。     

盐矿卤水中钙镁离子的深度净化研究

本文将化学净化与吸附净化相结合,考察其对卤水中钙镁离子的深度净化效果.实验结果表明,在一定的pH值下,TD-11吸附剂能吸附去除卤水中的钙镁杂质离子,吸附剂对钙镁离子的吸附能力与活性基团类型有关,Na型基团的吸附能力较强,而H型基团吸附能力则较弱.吸附净化作为化学净化的后道工序,能有效脱除卤水中残存的钙镁离子,有望彻底解决钙镁杂质离子对真空制盐及两碱生产过程的不利影响.     

氢氧化镁煅烧氧化镁活性研究

研究了煅烧温度、煅烧时间和升温速率对工业氢氧化镁煅烧产物分解率与活性的影响,并用XRD分析了不同煅烧条件下产物的结构,发现当升温时间为4h时,在500℃煅烧6h所得产物有最低的CAA值.     

In‐situ Remediation of Hydrogen Fluoride During a Detonation Event

Hydrogen fluoride (HF) is a known product from the combustion or detonation of explosives formulated with fluoropolymer binder systems. This presents the user with elevated risk levels during unintended combustion events or detonations in confined situations. In an effort to remediate the production of HF, calcium disilicide (CaSi₂) was added to explosive formulations and the amount of HF formed was monitored. Viton A/calcium disilicide mixtures were made and the thermal decomposition characteristics studied using thermal gravimetric/differential thermal analysis (TG/DTA). The activation energy ranged from 145–190 kJ mol⁻¹, indicative of C F scission in the Viton A binder prior to calcium fluoride formation. An energetic formulation was prepared which consisted of approximately a 5/3 mass ratio of Viton A/CaSi₂. Combustion calorimetry in oxygen and air, and subsequent analysis of the residues using X‐ray diffraction (XRD) showed evidence of calcium fluoride (CaF₂) formation. The decrease in HF formation was determined by trapping off gases and subsequent analysis in anion exchange chromatography of combustion and detonation products. Upon introduction of calcium disilicide into the formulation, a small decrease in HF formation was observed along with appearance of calcium fluoride and free Si in the residue. Such products are consistent with the mechanism following a general decomposition path of 2F⁻+CaSi₂→CaF₂+2Si. Under detonation conditions, the decomposition path followed nearly the same route with a net ca. 30 % decrease in HF formation, but with a portion of the silicon oxidizing slightly further to SiO₂.     

溶剂置换干燥法制备纳米氧化镁粉体的研究

以MgCl2·6H2O和CO(NH2)2为原料,由均匀沉淀法制备氢氧化镁沉淀,采用溶剂置换直接煅烧法、溶剂置换箱式干燥法、溶剂置换微波干燥法和超临界CO2萃取干燥法除去沉淀中的湿分,再将干燥的氢氧化镁粉体经马弗炉煅烧得到纳米氧化镁粉体,通过透射电子显微镜和X射线衍射仪的表征与分析,研究不同溶剂置换干燥方式对纳米氧化镁粉体形貌、尺寸和团聚行为的影响;讨论了溶剂置换干燥的基本原理和溶剂置换的方法.