废弃烟滤嘴制备醋酸纤维素微球及其对Pb(Ⅱ)的吸附性能

采用双重乳液溶剂挥发法与气体发泡技术相结合的方法将从废弃卷烟滤嘴中再生得到的醋酸纤维素进行改性，制备出醋酸纤维素多孔微球。通过扫描电镜、氮吸附和压汞法考察了内水相发泡剂用量和搅拌速度对微球形貌、比表面积和孔结构的影响，并进一步研究了其对重金属Pb²⁺的吸附性能。结果表明：随发泡剂用量增大，微球粒径逐渐变大，比表面积先增大后稍有下降，由闭孔转化为贯通孔；随搅拌速度加大，微球粒径逐渐减小，比表面积呈增大趋势，高速搅拌下具有更多的贯通孔结构。静态吸附结果显示，所制备醋酸纤维素多孔微球对Pb²⁺吸附量可达57.6 mg/g,远远优于未采用发泡剂技术所得微球的吸附性能。吸附动力学以及吸附等温实验表明该醋酸纤维素微球对Pb²⁺的吸附符合准二级动力学模型和Freundlich吸附等温模型。     

新型淀粉基微球对Cu~(2+)、Pb~(2+)吸附性能的研究

研究了新型淀粉基微球对Cu2+、Pb2+的吸附性能,结果表明,淀粉基微球对Cu2+的吸附能力强于Pb2+,对Cu2+、Pb2+的吸附率可达到85%以上,是一种有效处理重金属离子废水的处理剂。     

漆酚缩甲醛聚合物微球的制备及其吸附性能

本文利用悬浮缩聚的方法合成漆酚缩甲醛聚合物微球,考察悬浮缩聚过程中单体的预分散、分散剂用量、单体的预聚、油水比例、催化剂用量、反应温度以及搅拌速度等对微球的形貌结构与性能的影响。结果表明,漆酚单体经预聚合后,在Mg(OH)2分散剂的作用下分散于甲醛水溶液中;在弱碱催化剂NH3·H2O的作用下,当油水比R=0.163时,搅拌速度r=300r/min时,于80℃～85℃进行悬浮缩聚反应,可以得到粒径为300μm,内部为多孔结构的聚合物微球。微球可以吸附废水中的重金属离子Cu2+、Pb2+和Cd2+等,其吸附选择性为Pb2+(21.9mg/g)Cu2+(21.3mg/g)Cd2+(7.1mg/g)。     

负载玫瑰香精多孔微球的制备及缓释性能研究

以分散聚合合成的单分散聚苯乙烯微球作为种子微球,采用两步种子溶胀法制备多孔聚苯乙烯-二乙烯苯微球,并吸附玫瑰香精制备了香精多孔微球。利用马尔文激光粒度仪、比表面积孔径分布测定仪(BET)、热重分析仪(TGA)、扫描电镜(SEM)对种子微球和多孔微球的粒径、比表面积和孔结构、缓释性能、表观形貌进行了分析表征。结果表明:种球的粒径随着分散介质中无水乙醇体积分数的增大而增加;随着溶胀剂邻苯二甲酸二丁酯(DBP)用量的增加,多孔微球的平均粒径变大,分布变宽;随着交联单体二乙烯苯(DVB)用量增加,多孔微球平均粒径减小,分布变窄;以甲苯为致孔剂制备的多孔微球单分散性最好。当V(DBP):m(种球)=3:1,V(DVB):V(苯乙烯)=4:0时,制备的多孔微球的平均粒径约为4μm。以此多孔微球负载玫瑰香精,可以减缓香精的释放速率,提高起始分解温度,实现对香精的缓释。     

微球吸附剂的制备及其脱附性能研究

以明胶为原料,采用乳液聚合法制备了一种新型微球吸附剂,采用激光粒度仪、全自动比表面积和孔隙分析仪及扫描电镜(SEM)等对其进行了表征,并将其用于糖精钠中和液的吸附,考察了其脱附性能。结果发现,微球粒径分布均匀,平均粒径约为35μm,BET比表面积为0.283 8 m~2·g~(-1),且耐酸碱性强。脱附结果表明,微球在10 g·L~(-1) NaOH溶液中的脱附率达到88%,最佳脱附温度为30℃、时间为80 min,且可重复使用。     

腐植酸树脂/二氧化硅复合材料制备及其对重金属离子的吸附性能

以腐植酸和水玻璃为原料,采用酸化共沉淀方法制备了腐植酸树脂/SiO2复合材料. 在腐植酸树脂中引入SiO2无机网络后,比表面积有较大提高,在水溶液中的稳定性明显改善. 通过差热分析、傅立叶红外光谱、扫描电镜、比表面积测定等方法对样品进行了表征,研究了复合材料对Pb2+, Cd2+, Ni2+, Cu2+四种典型重金属离子的吸附性能,同时探讨了腐植酸组分对重金属离子的吸附机理. 结果表明,复合材料中的腐植酸组分对重金属离子的主要吸附形式应为离子交换吸附和络合(或螯合)吸附,复合材料对4种重金属离子有良好的吸附能力,对Pb2+, Cd2+, Ni2+, Cu2+的饱和吸附量分别为262.5, 43.55, 23.58, 45.54 mg/g,与同类吸附材料相比处于领先水平,对4种重金属离子的等温吸附符合Langmuir模型.     

W/O/W乳液法制备多孔聚合物微球

采用W/O/W乳液法制备了多孔聚合物微球(聚苯乙烯-二乙烯基苯)(PSDS),通过扫描电子镜、激光粒度仪、孔径及比表面积分析仪等对微球进行了表征,研究了乳化剂类型、分散剂用量及搅拌速率等对PSDS微球形貌、粒径等性能的影响。结果表明:不同种类乳化剂(Span-80、十六烷基三甲基溴化铵、OP-10)均能得到聚合物微球,以Tween-80为乳化剂,形成的PSDS不规则,以Span-80为乳化剂,PSDS的粒径分布较窄;分散剂用量增加,PSDS微球粒径变小,粒径分布变窄;搅拌速率越快,PSDS微球的粒径越小,粒径分布越窄;典型PSDS的比表面积为175.3m~2/g,孔容为0.35cm~3/g,平均孔径为0.86 nm。     

双重Pickering乳液法制备聚丙烯酰胺多孔微球及应用

采用亲水性气相二氧化硅N20和疏水性气相二氧化硅H30复配表面活性剂制备O/W/O型双重乳液,以此为模板,聚合中间相,挥发内相制备聚丙烯酰胺(PAM)多孔微球,并用于染料分子亚甲基蓝的吸附。结果表明：乳液显微镜照片显示水油比对双重乳液的形成有很大的影响,当水油比(O₁/W)/O₂为(1/2)/2时,可得到稳定的双重乳液;扫描电镜(SEM)照片显示PAM多孔微球基本呈球形,但粒径不均匀,球体表面粗糙,内部为空心结构;激光粒度仪(DLS)结果表明PAM微球平均粒径为356nm,多分散系数(PDI)为0.718,比表面积为230m²/g,粒径分布宽;在吸附温度35℃、吸附时间5min时对亚甲基蓝的吸附率为98.89%,最大吸附率超过99%,在吸附速率和吸附率上均优于传统PAM吸附剂,本研究为染料废水的处理提供了新方法。     

超大孔聚丙烯酰胺晶胶微球的制备及其生物相容性和吸附性能

利用反相悬浮结合溶剂结晶致孔法制备了具有超大孔隙、球形度良好的聚丙烯酰胺晶胶微球,晶胶微球平均粒径为234.1 mm,孔径约为10～50 mm。采用原位接枝法,将2-丙烯酰胺基-2-甲基-1-丙烷磺酸（AMPSA）接枝到晶胶微球孔隙表面上,得到了带有磺酸基团的阳离子交换晶胶微球。考察了晶胶微球的生物相容性和吸附蛋白质及重金属离子Cu²⁺的性能,结果表明：在大肠杆菌培养液中,添加晶胶微球,对大肠杆菌的生长影响不大。接枝了AMPSA的晶胶微球表现出更强的吸附Cu²⁺的能力,吸附容量达到1.14 mmol·g^-1。同时,接枝后的晶胶微球也具有一定吸附蛋白质的能力,溶菌酶的吸附容量达到54.5 mg·g^-1。因此,该大孔晶胶可望在微生物固定化、生物分离和重金属离子吸附中会发挥更大的作用。     

超大孔聚丙烯酰胺晶胶微球的制备及其生物相容性和吸附性能

利用反相悬浮结合溶剂结晶致孔法制备了具有超大孔隙、球形度良好的聚丙烯酰胺晶胶微球,晶胶微球平均粒径为234.1μm,孔径约为10~50μm。采用原位接枝法,将2-丙烯酰胺基-2-甲基-1-丙烷磺酸(AMPSA)接枝到晶胶微球孔隙表面上,得到了带有磺酸基团的阳离子交换晶胶微球。考察了晶胶微球的生物相容性和吸附蛋白质及重金属离子Cu2+的性能,结果表明:在大肠杆菌培养液中,添加晶胶微球,对大肠杆菌的生长影响不大。接枝了AMPSA的晶胶微球表现出更强的吸附Cu2+的能力,吸附容量达到1.14 mmol·g-1。同时,接枝后的晶胶微球也具有一定吸附蛋白质的能力,溶菌酶的吸附容量达到54.5 mg·g-1。因此,该大孔晶胶可望在微生物固定化、生物分离和重金属离子吸附中会发挥更大的作用。     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

茶多酚提取方法进展

本文综述了国内外现有茶多酚提取方法的现状以及近期的研究进展，并对其优缺点进行了评价。这将有助于中低档茶的综合利用和茶多酚的进一步开发应用。     

几种针状焦性能对比

针状焦分石油系和煤系两大类,这主要取决于针状焦的原料来源。在同一系列中由于原料不同和工艺条件不同 ,针状焦的各自性能也不相同。针状焦是生产超高功率石墨电极和高功率石墨电极的主要原料 ,针状焦的性能对石墨电极的质量有至关重要的影响。所以对针状焦性能以及其对石墨电极质量影响的研究十分必要的。以下是常用的几种进口针状焦和国产针状焦的性能对比。１原料性能分析对比原料试样包括４种针状焦 ,其中两种为进口针状焦：三菱针状焦和新日化针状焦;另两种为国产针状焦：鞍山针状焦和锦州针状焦。其中除锦州针状焦是石油系针状焦外…     

用两个形状指数表征粉煤灰颗粒形貌的研究

引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。