磺化聚醚醚酮纳米纤维膜的制备及其吸附性能

通过静电纺丝法制备了不同磺化度的磺化聚醚醚酮(SPEEK)纳米纤维膜,运用扫描电镜、热重分析仪分别对纤维的形貌和热性能进行了分析,并利用紫外-可见分光光度计研究了纤维膜对亚甲基蓝染料的吸附行为。结果表明:随着磺化度的增加,纺丝束流的稳定性得到改善,纤维直径减小;纤维膜对亚甲基蓝具有良好的吸附能力,在p H值=7时其对亚甲基蓝的去除率最大,平衡吸附时间约为90min;热力学分析表明,使用Freundlich模型描述SPEEK纳米纤维膜对亚甲基蓝的吸附行为更加合理;动力学分析表明,SPEEK纳米纤维膜对亚甲基蓝的吸附遵循准二级动力学模型。     

碳纳米管-聚丙烯腈纳米纤维膜的制备及对亚甲基蓝的吸附

采用静电纺丝技术制备碳纳米管-聚丙烯腈(CNT-PAN)复合纳米纤维膜,以期利用CNT增强PAN纳米纤维的力学性能和染料吸附性能。通过扫描电子显微镜、物理吸附仪和电子万能试验机等对不同CNT含量的复合纤维膜的微观结构、孔隙率、比表面积以及力学性能进行了表征分析。以亚甲基蓝为模板分子研究了不同条件下纳米纤维膜对染料的吸附效果。结果表明,随着CNT含量的增加,纳米纤维的直径略微增大,膜孔隙率和孔径变化不大。CNT的加入明显提高了PAN的力学性能和对染料的吸附性能,CNT的质量分数为10%时CNT-PAN复合纳米纤维膜的性能最佳,与纯PAN纤维膜相比,断裂强度提高了152%,染料吸附率提高了将近30%。     

PAN/β-CD复合纳米纤维膜的制备及吸附性能研究

以聚丙烯腈(PAN)和β-环糊精(β-CD)为原料,以N,N-二甲基甲酰胺为溶剂,通过静电纺丝制备出不同β-CD含量的PAN/β-CD复合纳米纤维膜。采用扫描电镜、傅里叶变换红外光谱仪、X射线衍射仪、孔径及比表面积测定仪、紫外分光光度计对纳米纤维膜的形貌、结构、比表面积以及吸附性能进行了表征。结果表明:PAN/β-CD复合纳米纤维膜中,β-CD和PAN之间为简单的物理共混,β-CD保留了空腔结构;随着β-CD含量的增加,PAN/β-CD复合纳米纤维膜的直径增加,比表面积减小,对亚甲基蓝的吸附率增加;当β-CD相对PAN质量分数为40%时,PAN/β-CD复合纳米纤维膜的纤维直径粗细均匀,比表面积较小,为9.652 m2/g,对亚甲基蓝的吸附率较大,为97.48%。     

ZnO/PAN基纳米碳纤维膜的制备及其光催化性能的研究（英文）

采用N,N-二甲基甲酰胺(DMF)为极性溶剂溶解醋酸锌(Zn(Ac)_2·2H_2O),然后加入聚丙烯腈(PAN)制得前驱体溶液,采用静电纺丝法制备PAN/Zn(Ac)_2复合纳米纤维膜,将PAN/Zn(Ac)_2复合纳米纤维膜在真空管式炉中经过高温煅烧得到PAN基碳纤维/氧化锌(CF/ZnO)纳米纤维膜,以CF/ZnO纳米纤维膜为光催化剂,亚甲基蓝为污染物,进行光催化降解实验,研究了Zn(Ac)_2含量对PAN/Zn(Ac)_2复合纳米纤维形貌、性能的影响,以及CF/ZnO纳米纤维膜的光催化性能。结果表明:Zn(Ac)_2的掺入并未对PAN的化学结构产生影响,二者属于物理结合,Zn(Ac)_2能较均匀地分布在纤维的内部;随着Zn(Ac)_2含量的增加,CF/ZnO纳米纤维膜对亚甲基蓝的降解率会提高,当Zn(Ac)_2质量分数(相对PAN)为60%时,可见光照射80 min后CF/ZnO纳米纤维膜对亚甲基蓝的降解率达到91.6%。     

氧化铈/碳纳米复合纤维膜的制备及吸附和催化性能

碳纳米纤维材料目前应用越来越广泛,将金属氧化物修饰到碳纳米纤维材料上,可以防止金属氧化物纳米颗粒的团聚。选用聚丙烯腈以及N,N-二甲基甲酰胺作为原材料,利用静电纺丝-煅烧法制备了氧化铈/碳纳米复合纤维膜,研究了复合纤维膜对水中As³⁺、As⁵⁺的吸附率,并以亚甲基蓝溶液作为污染物,研究了其催化和氧化性能,为材料优化和性能提升奠定了基础。     

Ag掺杂ZnO纳米纤维的制备及其光催化性能

采用静电纺丝技术制备了PVP/Zn(CH3COO)2、PVP/Zn(CH3COO)2/Ag NO3复合纳米纤维,经煅烧后分别得到Zn O纳米纤维和Ag/Zn O复合纳米纤维。利用SEM、TG、FTIR、XRD对煅烧前后的纤维形貌和结构进行表征。用紫外灯作为光源,以亚甲基蓝为目标降解物,考察了Zn O和Ag/Zn O复合纳米纤维的光催化活性。结果表明:银的掺入能有效地提高Zn O对亚甲基蓝的光催化降解性能,且降解性能随着Ag质量分数的增加而逐渐提高。     

纤维素纳米纤维膜的改性及其染料吸附性能

采用静电纺丝技术制备醋酸纤维素纳米纤维膜，用氢氧化锂水解后得到纤维素纳米纤维膜。通过3-氯-2-羟丙基三甲基氯化铵（CHPTAC）和一氯乙酸共同改性，制备了双性纤维素纳米纤维膜。利用紫外分光光度计测试双性纤维素纳米纤维膜对茜素绿（AG25）和亚甲基蓝（MB）的吸附性能，并考察了pH、温度、染料初始浓度对吸附量的影响。结果表明，双性纤维素纳米纤维膜对AG25和MB染料的最大吸附量分别达到 240 mg/g和 128 mg/g，并且对两种染料在第4个循环时仍保持84%的吸附效率。同时，发现pH是影响双性纤维素纳米纤维膜的染料吸附性能的关键因素，在吸附没有饱和之前，染料吸附量随着染料浓度的增加而增加，而吸附效果对温度没有依赖性。     

pH值对PVDF/PDA/CD功能化纤维膜吸附性能的影响

利用静电纺丝结合原位自聚合技术制备了聚偏氟乙烯(PVDF)/聚多巴胺(PDA)/环糊精(CD)功能化纤维膜,采用傅里叶变换红外光谱仪和扫描电子显微镜对纤维膜结构与形貌进行表征,考察了PVDF/PDA/CD纤维膜对不同pH值亚甲基蓝溶液的吸附性能。结果表明：功能化改性后,PDA与CD分子附着于PVDF纤维表面,增大了PVDF/PDA/CD纤维的直径和表面粗糙度,提升了PVDF/PDA/CD纤维膜的吸附能力;当亚甲基蓝溶液的pH值为1～10时,该功能化纤维膜在碱性环境下具有更高的吸附能力;随吸附时间延长,功能化纤维膜对亚甲基蓝的吸附量增加,吸附过程符合伪二阶动力学模型,说明PVDF/PDA/CD功能化纤维膜对亚甲基蓝的吸附过程主要受化学吸附作用控制。     

溶液喷射纺丝制备PES-C/PES-CB复合纳米纤维膜

通过在酚酞聚醚砜(PES-C)纺丝液中添加不同含量的两性离子改性的酚酞聚醚砜(PES-CB),然后利用溶液喷射纺丝法制备PES-CB/PES-C复合纳米纤维膜,并通过扫描电子显微镜、红外、差示扫描量热仪、热重分析、接触角等对复合纳米纤维膜进行了测试表征,最后将复合纳米纤维膜进行淀粉溶液过滤测试。结果表明,随着PES-CB含量的增加,纳米纤维的直径不断减小,当PES-CB添加量达到30%时,复合纳米纤维膜的平均直径减小到300nm左右。同时由于两性离子支链的存在,纤维膜的亲水性也得到提高,但其耐热性降低。过滤测试结果表明,随着PES-CB含量的增加,膜的抗污染能力得到明显提高,当PES-CB添加量达到30%时,过滤淀粉溶液的水通量恢复率(FRR%)达到83%左右。结合纺丝过程及过滤性能测试来看,PES-CB添加量在30%左右制备的复合纳米纤维膜综合性能最佳。     

静电纺丝法制备聚酰亚胺/碳化硅复合纳米纤维

利用聚酰胺酸(PAA)溶液和纳米碳化硅(SiC)混合物作为纺丝液,通过静电纺丝法制备聚酰胺酸/碳化硅(PAA/SiC)复合纳米纤维,PAA/SiC复合纳米纤维亚胺化后得到聚酰亚胺/碳化硅(PI/SiC)复合纳米纤维。研究了PAA溶液中PAA含量、纺丝电压、纺丝距离及SiC含量对PAA/SiC复合纳米纤维形貌的影响,利用热重法分析了PI/SiC复合纳米纤维的热稳定性。结果表明,使用固含量为15%的PAA溶液作为基体材料,再将纳米SiC以6%的含量均匀分散于基体材料中制备出纺丝液,在纺丝电压为10～18kV左右、纺丝距离为15cm时,可制备出直径250nm左右、光滑、连续、SiC分布均匀的PAA/SiC复合纳米纤维。PI/SiC复合纳米纤维热稳定性优异,氮气气氛中热分解温度为550℃。     

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.     

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。     

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。     

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。