臭氧氧化炭黑表面改性的研究

在固定床反应器中对不同条件下臭氧氧化炭黑表面改性进行了实验研究.结果表明,普通炭黑经过臭氧氧化处理后其挥发份提高,pH值由8.25变为3-4.臭氧氧化炭黑表面改性的优化条件为:温度为常温;反应时间为60-90 min;臭氧产生量为2.45 g/h;气量为0.4 m3/h.     

PET表面改性研究进展

综述了国内外聚对苯二甲酸乙二醇酯(PET)的表面改性研究进展.PET表面改性方法主要有:化学接枝改性、紫外光辐照接枝改性、高能射线辐照接枝改性、等离子体处理接枝改性以及臭氧氧化改性等;通过PET表面改性,可以改善PET的亲水性、抗静电性、粘附性和生物相容性等性能;介绍了改性PET在相关领域中的应用;指出PET的表面改性...     

臭氧微泡技术提高炭黑在水溶液中的分散稳定性

为了在水性体系下获得高分散性的炭黑,本实验通过臭氧微米气泡技术对炭黑表面进行氧化,并通过沉降实验检测了炭黑在水性体系下的分散稳定性,利用傅立叶红外光谱仪(FT-IR),X光电子能谱仪(XPS),元素分析仪,热分析仪(DTA-TG)、扫描电子显微镜(SEM)分别对臭氧氧化改性后炭黑的表面基团结构,表面含氧量进行了表征.结果表明,经过臭氧氧化改性后的炭黑,大量的羧基、羟基等亲水性含氧基团被引入,即使高速(3500 r/min)离心沉降60 min后,炭黑在水溶液中的稳定性系数仍然可达到93.6%.     

碳基材料在臭氧催化氧化法中的研究应用

综述了碳基材料的改性方法及对难降解有机物的去除效果,讨论了初始pH值、催化剂投加量、臭氧投加量对臭氧催化氧化的影响,分析了碳基材料在臭氧催化氧化中的重要意义以及作为催化剂的改性研究方向,对新型碳基材料催化臭氧具有重要的参考意义。     

碳基材料在臭氧催化氧化法中的研究应用

综述了碳基材料的改性方法及对难降解有机物的去除效果,讨论了初始pH值、催化剂投加量、臭氧投加量对臭氧催化氧化的影响,分析了碳基材料在臭氧催化氧化中的重要意义以及作为催化剂的改性研究方向,对新型碳基材料催化臭氧具有重要的参考意义。     

信息

材料表面化学镀方法的介绍目前研究了一种在由树脂构成的材料表面进行化学镀的方法。该方法包含以下步骤:(1)臭氧处理步骤,在该步骤中,将待处理材料浸泡在含有臭氧的溶液中,从而在材料表面形成一层改性层;(2)表面层去除步骤,在经过臭氧处理后,材料的表面经紫外线辐射处理后去除被改性后的表面层。磁性电镀本研究涉及磁性电镀或电沉积的技术。     

臭氧氧化处理法对聚丙烯表面涂装性的改良研究 Ⅰ.聚丙烯表面的臭氧氧化反应过程

讨论了用臭氧氧化法对聚丙烯表面进行涂装性改良时,聚丙烯均聚物、乙烯-丙烯嵌段共聚物及无规共聚物表面的臭氧氧化反应过程。ATR-IR、ESCA及SEM的结果表明,3种聚丙烯有相同的反应过程,即臭氧氧化反应首先使材料表面的聚丙烯部分生成PP-OH和PP-C=CH,然后-C=C-被臭氧氧化分解生成酮、醛或羧基等,最终氧化产物以羧基为主。臭氧氧化主要发生在处于材料表面非晶态中的丙烯叔H部分上。但由于臭氧对聚丙烯及其共聚物表面的攻击方式不同,溶剂洗净后3种聚丙烯状态将有很大的差异。     

液相臭氧法改性炭黑及分散性能研究北大核心

为了提高炭黑在水溶液中的分散性,通过液相臭氧氧化法对炭黑表面进行氧化改性,并利用沉降实验表征炭黑在水溶液中的分散稳定性,同时也利用TEM、纳米粒度与电位分析仪表征改性前后炭黑的分散性及平均粒径。此外,还分别利用傅里叶红外光谱仪、热重分析仪、元素分析仪表征臭氧改性炭黑的表面基团结构及含量、元素组成。结果表明:炭黑经过臭氧改性后,引入了大量的羧基、羟基等酸性含氧官能团,并且在水溶液中的分散性明显提高。在3 500 r/s的离心机中离心60 min时,其透光率为26.1%,而此时原样炭黑分散液的透光率却为96.7%。     

石墨烯改性TiO2催化臭氧氧化降解p-CBA的研究

采用碳化热解法在TiO₂催化剂表面制备石墨烯层，并对其进行XRD、Raman、NH₃-TPD、BET、pH_zpc等表征。以对氯苯甲酸(p-CBA)为目标物，考察石墨烯改性TiO₂在催化臭氧氧化过程中的效能。结果表明，热解温度、碳源投量、固化剂投量等因素对催化剂的活性有较大影响。负载石墨烯层可显著增加TiO₂催化剂的比表面积，并使其表面酸性增强，因而提高其催化臭氧氧化活性。另外，考察了溶液pH、叔丁醇对改性TiO₂催化臭氧氧化过程的影响。溶液pH为6时，对氯苯甲酸的去除率最低。叔丁醇严重抑制了对氯苯甲酸的降解反应，间接证明了羟基自由基是催化臭氧氧化过程中的主要活性氧化物种。重复使用实验结果表明，改性后的催化剂具有良好的稳定性。     

液相臭氧法改性炭黑及分散性能研究

为了提高炭黑在水溶液中的分散性,通过液相臭氧氧化法对炭黑表面进行氧化改性,并利用沉降实验表征炭黑在水溶液中的分散稳定性,同时也利用TEM、纳米粒度与电位分析仪表征改性前后炭黑的分散性及平均粒径。此外,还分别利用傅里叶红外光谱仪、热重分析仪、元素分析仪表征臭氧改性炭黑的表面基团结构及含量、元素组成。结果表明:炭黑经过臭氧改性后,引入了大量的羧基、羟基等酸性含氧官能团,并且在水溶液中的分散性明显提高。在3 500 r/s的离心机中离心60 min时,其透光率为26.1%,而此时原样炭黑分散液的透光率却为96.7%。     

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.     

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。     

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…     

聚酰亚胺的合成法

本文评述了缩聚型聚酰亚胺的主要合成方法和近年来国际上在合成中所做的探索。