THE APPLICATION OF CATIONIC POLYACRYLAMIDE AS DRAINAGE AND RETENTION AIDS

INTRODUCTIONIn recent years, with the rapid development of paper-making technology[1], such as improvement of pa-per-machine speed, extensive use of high yield and recycling pulp, and more closed white water systems, the environment of papermaking has changed greatly and this has brought many problems, Such as water temperature increasing and water quality becoming worse, large amount of fines in pulp, and more and more aninonic trash in pulp and water. These causes drainability of pulp a…     

STUDY ON A NEW NONIONIC MICRIOPARTICLE RETENTION SYSTEM

Microparticle retention system, developed lately, mainly consists of cationic polymers and anionic inorganic substances, such as Hydrocol system consisting of cationic polyacrylamide/modified bentonite and Compozil system[2] with cationic starch/anionic silica sol. The principle of electrostatic interaction has been adopted for these systems. Whereas if there are plentiful anionic trashes in systems, their efficiency will not embody primely. Although anionic trash catcher (ATC) could be adde…     

Annealing temperature-dependent electrochemical properties of Aeroxide P25 TiO_2 nanoparticles as anode material for lithium storage

TiO_2 has been widely studied as an important electrode material for electrochemical energy storage.Understanding its relationship between textural properties and electrochemical characteristics is essential to boosting its practical performances. Herein, Aeroxide P25 TiO_2 nanoparticles annealing at different temperatures(400–600 °C) were investigated as an anode material of lithium ion battery. Their evolution in crystal phase and microstructural characteristics were characterized by XRD and BET surface analysis, and their lithium storage properties in half-cells were evaluated by various electrochemical analyses, including cyclic voltammetry, cycling testing, and electrochemical impedance spectroscopy. It was found that the lithium storage properties were critically dependent on the size of TiO_2 anode materials. Pristine P25 initially exhibited the highest initial discharge specific capacity due to its smallest particle size; however, rapid capacity loss occurred during extended cycling. The annealing process was found to effectively enhance the cycling stability of TiO_2 although possessing a large particle size and smaller surface area. Typically, P400 showed the best performances in cycling stability, capacity retention ratio, and rate capability, which is mainly attributed to the synergistic effect of high crystallinity, reasonable particle size, and less internal resistance. This study provides an instance of optimizing the textural properties of metal oxides for advanced LIB anode material applications.     

APPLICATION OF CATIONIC POLYMERIC MICROPARTICLES ON RETENTION AND DRAINAGE

1.INTRODUCTIONThe microparticles retention and drainage technologywas brought in 1980s. It brings striking effect whenused in wet-end in paper-making. The retention offines and fillings and the drainage of pulp improved alot, meanwhile, the evenness also improved. So, mi-croparticles retention and drainage system is the maindeveloping direction of retention and drainage aids on paper-making industry.All microparticles in microparticle system we use currently are inorganic anionic. It rea…     

膨润土的改性实验及表征

为提高膨润土对低浓度瓦斯的吸附性能,用质量分数3%的硫酸溶液和正二十四烷通过化学浸渍法对膨润土原土进行改性实验。对硫酸改性膨润土、正二十四烷改性膨润土、膨润土原土进行N2的吸附、比表面积、孔容和孔径测试。通过改性前后数据对比可知,改性后膨润土的吸附量、比表面积、孔容相应的增大,且硫酸改性膨润土的性能优于正二十四烷改性膨润土。改性后膨润土对CH4的最大吸附量为5.36 mmol/g,比改性前增加了3.72 mmol/g,增量明显。     

APPLICATION OF BORON MODIFIED SILICA SOL ON RETENTION AND DRAINAGE

INTRODUCTIONRecently with the high speed, large-scale develop-ment of papermaking, in the manufacture of paper and paperboard conventional single and dual reten-tion and drainage systems cannot obtain satisfying re-tention and drainage. So in 1980 microparticulate systems appeared. Because of its superiority such as good retention effectiveness on fine and chemicals, improving drainage and paper formation, reducing waste water and enhancing the concentration of white water for good recover…     

固着剂助留剂协同控制纸浆溶解与胶体物质的机理

 将聚胺固着剂（PA）、阳离子聚丙烯酰胺助留剂（CPAM）单独以及协同处理旧新闻纸浆,采用聚焦光束反射测定仪（FBRM）考察浆料中残余胶体粒子的数量、尺寸和尺寸分布,探讨固着剂/助留剂协同控制纸浆中溶解与胶体物质（DCS）的效果和机理。结果表明,PA单独处理纸浆时,会产生部分不能固着于纸张纤维或不被纤维网络截留的粒子聚集体;CPAM单独处理纸浆时,其电荷容易被DCS中和,导致其减少纸浆胶体粒子数量的效果明显下降,但不产生粒子聚集体;PA/CPAM协同处理纸浆时,后续的CPAM处理能将PA预处理纸浆时产生的部分粒子聚集体进一步固着到纸张纤维上,达到更好地降低胶体粒子数量的效果,且不产生更大的粒子聚集体。     

球磨-酯化复合改性槟榔芋淀粉对Pickering乳液形成的影响

为了提高淀粉颗粒的乳化能力,以球磨-酯化复合改性槟榔芋淀粉为颗粒乳化剂,大豆油为油相,制备水包油型Pickering乳液。采用激光粒度仪、研究级正置显微镜、流变仪等对Pickering乳液外观、液滴粒径、显微形态及动态流变特性进行表征,考察淀粉颗粒质量浓度(1、5、10、20、30mg/mL)和油相体积分数(10%、20%、30%、40%、50%)对乳液稳定性和流变特性的影响。研究发现:增加颗粒质量浓度导致乳化相体积增加,液滴粒径减小;随着油相体积分数的增加,乳化相体积增加,液滴粒径增大。当颗粒质量浓度为20mg/mL,油相体积分数为40%时,乳液的乳析现象明显改善。球磨-酯化复合改性槟榔芋淀粉颗粒吸附在油/水界面,有效抵抗了液滴聚结,使乳液在储存30d后仍表现出良好的稳定性。流变特性表明:乳液内部存在弹性凝胶网络结构,随着颗粒质量浓度和油相体积分数的增加,液滴间堆积变得更紧密,从而增加了乳液黏度和凝胶强度,使其抵抗形变能力增强。球磨-酯化复合改性槟榔芋淀粉颗粒具有良好的作为Pickering乳液稳定剂的潜力。     

SiC颗粒特性对无压熔渗SiCp/Al复合材料热物理性能的影响

采用粉末注射成形-无压熔渗相结合技术制备出了电子封装用高体积分数SiCp/Al复合材料. 重点研究了SiC粒径、体积分数以及粒径大小等颗粒特性对所制备复合材料热物理性能的影响规律. 研究结果表明,SiCp/Al复合材料的热导率随SiC粒径的增大和体积分数的增加而增加;SiC粒径的大小对复合材料的热膨胀系数(CTE)没有显著的影响,而其体积分数对CTE的影响较大. CTE随着SiC颗粒体积分数的增加而减小,CTE实验值与基于Turner模型的预测值比较接近. 通过对不同粒径的SiC粉末进行级配,可以实现体积分数在53%～68%、CTE(20～100℃)在7.8×10-6～5.4×10-6K-1、热导率在140～190W·m·K-1范围内变化.     

新疆夏子街膨润土矿物特性与活性白土产品性能的相关性分析

利用硫酸作为活化剂,对采自夏子街乌兰林格矿区的白色钠基膨润土、红白色钠基膨润土和钠钙基膨润土进行了活化实验。通过对不同原矿的测试分析及活化实验,探讨了原矿的各项指标对产品质量的影响规律,并初步分析二者之间的相关性。在2种加酸量的条件下,白色钠基膨润土的活化效果优于红白色钠基膨润土和钠钙基膨润土,而且产品的活化效果与原矿的吸蓝量、阳离子交换量之间有很好的线性关系。     

膨润土的纯化及脱水过程研究

采用湿法对广西宁明膨润土矿进行提纯，分别考察膨润土原土的粒度、浆液的液固比、搅拌时间及沉降时间对提纯效果的影响，并对产品用酸性无机絮凝剂絮凝沉淀后，再以醇类进行脱水处理。结果表明：当膨润土原矿的粒度为75—85目，浆液的液固比为12，搅拌时间为80min，沉降时间为120min时，可将膨润土原矿中蒙脱石含量从60％提高到83％左右。纯化过程的絮凝沉淀，能有效地分离出膨润土胶体溶液中的大量水分，脱水后提纯土具有良好的分散性。     

联苯胺系黄色双偶氮颜料的加和增效效应

在常规的重氮化偶合反应中,在合成C.I.颜料黄14的偶合组分中掺入结构相似的衍生物,由此制得一系列文题化合物。其颜色性能(如颜色强度、亮度和结晶颗粒度等)比单一颜料和机械拼混颜料有所改进,即产生了加和增效效应。多晶体X-射线衍射分析和电子显微镜分析表明:加和增效颜料性能改进的原因是由于形成了取代式固溶体所致。     

壳聚糖季铵盐改性膨润土的制备及其对印染废水处理

 以膨润土为原料,利用壳聚糖季铵盐为改性剂,探讨制备壳聚糖季铵盐改性膨润土的最佳条件。结果表明,土液比为50g·L-1,原土粒度为0.150mm,壳聚糖季铵盐溶液的质量浓度为1.5g·L-1,微波加热时间7min,浸泡时间30min条件下制备的改性膨润对模拟印染废水脱色率较好,通过正交实验,确定了改性膨润土处理模拟印染废水的最优条件为：pH值为3.0,投土量为14g·L-1,搅拌速度为150r·min-1,搅拌时间为20min,离心时间为8min。对直接耐晒翠兰和酸性橙红的脱色率分别高达94.6%和80.3%,改性土对直接耐晒翠兰的脱色效果优于对酸性橙红的脱色效果。     

以钙基膨润土为原料的可逆变色干燥剂制备

为制备以钙基膨润土为原料的可逆变色干燥剂,经过分析研究钙基膨润土的吸湿机理与吸湿性能,通过多种尝试与多条途径,以及大量实验、测试、比较,筛选出了能够提高钙基膨润土吸湿能力的吸湿增效剂和可以加强其物理强度的粘合剂,优化了各种组分的配比,优选出最适宜的材料配比方案,基本确定了最佳的制备条件.这种钙基膨润土干燥剂具有足够的吸湿容量、持久的吸湿性能、良好的变色特征,循环使用不易潮解,制备过程工艺简单,使用方便,成本低廉.     

超声波强化均匀沉淀法制备纳米TiO2

为了改善纳米TiO2的分散性能和细化其颗粒尺寸,采用超声波强化均匀沉淀法制备纳米TiO2.首先以工业级硫酸氧钛为原料,用均匀沉淀法制备纳米TiO2,通过对比试验来反映超声波对于制备纳米TiO2的影响.然后采用BET比表面积与孔隙度分析、扫描电子显微镜、透射电子显微镜、X射线衍射分析研究了超声波的强化作用.试验结果表明:超声波的强化作用具有明显的细化颗粒尺寸的作用;能增加纳米TiO2的比表面积、孔容积与孔径;能改善分散度,使颗粒粒径分布范围变窄.通过均匀沉淀过程能直接获得纯锐钛型纳米TiO2,而无需经过特定温度的煅烧定型,超声波作用对产物晶型无影响.     

明胶辅助-高温固相法合成LiNi_(0.5)Mn_(1.5)O_4高电压正极材料

以醋酸盐为原料,分别在4个不同煅烧温度条件下,采用明胶辅助-高温固相法制备获得尖晶石型Li Ni0.5Mn1.5O4正极材料,通过XRD、SEM、FT-IR和充放电循环考察了这4种产物的组成结构、颗粒形貌和电化学性能.结果表明:随着煅烧温度升高,材料的结晶度相应提高,初始放电比容量逐渐增大,样品的最大初始放电比容量为137 m Ah/g.经600℃退火处理的材料的粒径尺寸增大,空间群结构转变为Fd3m相和P4332相同时并存,循环稳定性和小倍率放电能力也随之得到改善,而900℃煅烧的材料则在高倍率下表现出较优的容量保持率.     

增效超分散剂对黄墨体系的应用性能研究

考察了联苯胺黄酸衍生物－－ＦＡ系列增效超分散剂对黄墨中黄颜料的分散性能，结果表明，选择合适的增效超分散剂与超分散剂配合使用，能明显改善体系的流动度，粘度和剪切稀化性等应用性能指标。     

改性微粒硅溶胶的研制及应用机理研究

The preparation and their application in papermaking of aluminium modified silica sol (AMS) and boron modified silica sol (BMS) were first investigated in China. At the same time the structures and configurations of AMS and BMS were first time authenticated. The modified silica sol microparticle system was detailedly and systemically studied with colloid charge titration. On the research of flocculation mechanism the laser sizer was also first time used to determine the floc size. Results showed that sodium silicate was treated and acidification was carried out by means of strongly acid cation exchange resins and obtained almost sodium free acid sols. The acid sol obtained after acidification was then made alkaline.     

铁负载膨润土对铀(VI)的吸附特性及机理研究

采用膨润土经提纯、钠化及负载铁等过程制备铁负载膨润土,通过静态吸附实验研究了pH、离子强度、吸附剂投加量、U（Ⅵ）初始浓度、阳离子Ca^2＋、Mg^2＋以及阴离子CO3^2-、HCO3^-等对铁负载膨润土吸附模拟废水中U（Ⅵ）的影响,进行了吸附过程动力学、热力学分析,并利用傅里叶红外光谱（FT-IR）、扫描电镜（SEM）探讨了相关吸附机理.试验结果表明,pH值和离子强度是影响吸附效果的重要因素,当溶液pH为6,离子强度为0.01 mol/L NaNO3,U（Ⅵ）初始浓度为19.08 mg/L,铁负载膨润土投加量为0.2 g/L,24 h吸附量达到88.06 mg/g.当pH〈6时,Ca^2＋、Mg^2＋、CO3^2-、HCO3^-的存在分别降低了铁负载膨润土对U（Ⅵ）的吸附效果,而pH〉7时影响作用不大.准二级动力学和Langmuir等温吸附模型对铁负载膨润土吸附U（Ⅵ）的拟合效果较好,SEM和FT-IR分析结果表明铁负载膨润土主要通过羟基络合及离子交换作用结合U（Ⅵ）进入其层间及表面.     

NPAM的非均相Mannich反应研究

本文研究了非离子型聚丙烯酰胺（ＮＰＡＭ）经非均相曼尼期（Ｍａｎｎｉｃｈ）反应制备粉状阳离子聚丙烯酰胺（ＣＰＡＭ）的反应条件，讨论了在不同水／乙醇体积比中ＮＰＡＭ的溶胀度与溶胀时间的关系及ＮＰＡＭ分子量与溶胀度及胺化度的关系，探讨了反应时间对ＣＰＡＭ的胺化度、溶解率及溶胀行为的影响，通过红外光谱分析，明确了产物的结构