微波法煅烧高岭土及合成洗涤助剂4A沸石

本文用微波法燃烧高岭土并合成４Ａ沸石。与传统高温热处理法相比,微波法燃烧的高岭土其活化深度好,增白程度高,粒度细,能耗大为降低,显示了明显的优越性。本文还采用燃烧后的活性高岭土为原料,在微波辐射下进行４Ａ沸石的合成,并用ＸＲＤ、ＤＴＡ、ＳＥＭ、白度计、钙离子交换度等进行表征。与传统水热处理法相比,微波法所得样品在结晶度、白度和钙离子交换能力方面均优势,且大大地加快了沸石晶化反应速率。经动力学处理,     

偏高岭土水热合成4A沸石晶化行为的研究

以偏高岭土为原料合成4A沸石,由于其合成过程工艺简单,成本低而一直受到普遍的关注,对于该法晶化过程的行为研究,近年来陆续出现报道,Rocha等^[1]研究认为偏高岭土在碱液中缓慢溶解,形成含SiO3^2-,SiOH基团和Al(OH)4^-的溶液,逐步缩合为硅铝酸钠凝胶,再进一步形成4A沸石晶粒并通过结构重排而转变为4A沸石,王建等^[2]研究提出偏高岭土在NaOH溶液中部分溶解,且迅速转变为偏高岭土,并伴有硅铝酸钠凝胶产生,同时偏高岭土也不断在碱液的作用下凝胶化,生成的凝胶再进一步转变为4A沸石,因而合成的4A沸石产品与化学合成法存在着较大的差异。对偏高岭土合成4A沸石的晶化历程,作者曾进行过研究^[3],发现偏高岭土在碱液中溶解很小,由偏高岭土转为4A沸石晶型,主要是在偏高岭土固相的基础上进行的。本文似从合成过程的机理方面,探讨偏高岭土合成4A沸石的晶化过程行为及其与化学法合成产品差异的关键所在。     

偏高岭土合成4A沸石机理的研究

用XRD、FT IR、ICP、SEM、化学分析等方法研究了偏高岭土合成4A沸石的晶化反应机理。偏高岭土在NaOH溶液中部分溶解 ,且结构迅速转变为偏高岭土 * ,并伴有硅铝酸钠凝胶形成。偏高岭土 *也不断在碱液的作用下凝胶化 ,生成的凝胶进一步再转变为4A沸石 ,这两个过程在大部分反应时间里是同时进行的 ,直到晶化结束。液相参与凝胶、4A沸石前驱及晶核等的形成和4A沸石的成长。偏高岭土 *的凝胶化速度是整个晶化过程的决定步骤 ,该晶化过程极易形成大量聚晶。     

微波辐射法合成NaX分子筛

NaX是低硅铝比的八面沸石,一般在低温水热条件下合成.因反应混合物配比不同,以及采用的反应温度不同,晶化时间为数小时至数十小时不等. 近年来,微波辐射方法被应用于无机及有机化合物的合成中.Chu Pochen等在专利文献中报道了微波辐射法在沸石分子筛合成中的应用,其中提到了NaX分子筛,但对合成     

超声法加入柠檬酸制备分子筛及其性能研究

以化学试剂为原料,在传统水热合成法的基础上,采用超声波法外加助剂(柠檬酸),通过改变柠檬酸的用量、晶化时间和晶化温度设计三水平三因素正交试验合成4A分子筛,采用XRD、SEM、FI-IR及钙离子交换性等方法进行分析表征,并探讨了制备4A分子筛的最优条件。结果表明,4A分子筛制备的最优条件为:晶化温度70℃,柠檬酸/Al_2O_3=0.75(摩尔比),晶化时间4h。4A分子筛对钙离子交换的Langmuir吸附等温方程为q=0.00012x/(1+0.024x)。钙交换能力达到310.71mg CaCO_3/g,钙离子交换的最佳吸附时间为1h,最佳吸附温度为35℃。     

离子选择电极法测定洗涤剂用沸石的钙离子交换性能

1 引言采用EDTA滴定、ICP和AA法测定洗涤剂用沸石的钙离子交换量时.需要将溶液与沸石分离后进行,因而不易测定交换过程中沸石的钙离子交换速率.而采用ISE法,可以在沸石与钙离子交换时,实时测定溶液中钙离子浓度随交换时间的变化,求得钙离子交换速率.本文采用ISE法测定洗涤剂用沸石的钙离子交换速率及交换量.2 实验部分2.1 仪器与试剂 pXS-215型离子活度计(上海雷磁仪器厂);钙离子选择电极(ISE)和甘汞电极(上海雷磁仪器厂);记录仪(上海大华仪器厂).洗涤剂用4A沸石(山东铝厂),0.1mol/L标准CaCl_2溶液,0.5mol/L NaOH溶液.     

超声波合成磁性4A沸石分子筛

为了解决微细粉末状沸石产品应用中与所处理溶液难以分离的问题, 在传统水热合成法合成4A沸石的晶化原料液中, 加入磁性Fe3O4微粒, 经过70 ℃, 功率为100 W的超声波晶化6 h, 合成了一系列Fe3O4含量不同的磁性4A沸石,并对其进行了XRD、SEM、IR、TG/DTA、EDX、磁化率及吸附性能等表征测试. 结果表明, 磁性4A沸石具有良好的磁稳定性, 其磁化率随Fe3O4含量的增加而增大; 磁性4A沸石对水中氟离子和六价铬的吸附与纯4A沸石性能相同, 其吸附速率可以用拟二级动力学方程来描述.     

超细4A分子筛的超声波低温快速合成

在低温条件下用超声波快速合成了4A分子筛.产物分别用XRD,IR,SEM和DSC等进行了表征.结果表明,用超声波法合成4A分子筛的速度是常规法的24倍.合成产物的白度为95%,钙离子交换容量为335mgCaCO₃/g4A分子筛,平均粒径为280nm.与采用常规方法合成的产物相比,超声波法合成的产物热稳定性有所下降.     

以高岭土为原料合成沸石分子筛的相变规律

以天然粘土矿物高岭土为原料, 采用水热晶化法合成了NaX, NaP和SOD三类沸石. 利用XRD、 静态饱和水吸附等测试手段详细考察了晶化温度、 初始反应混合物的碱浓度对沸石结晶的影响. 通过实验研究得到了三类沸石的结晶相区和结晶变化规律, 并优化出最佳合成工艺条件和相转变规律.     

利用磷肥副产物硅渣制备亚微米4A分子筛

以磷肥副产物硅渣制备的硅胶湿样和氢氧化铝为原料,溶胶-水热法合成了亚微米4A分子筛,采用XRD、SEM和FT-IR等分析手段进行了表征.结果表明采用硅胶湿样制备的产品形状规则、大小均匀;干基分子筛相对于CaCO3的钙离子交换容量为340 mg/g,白度为95%,与常规水热合成法制备的产品相比,其粒度较小、分布范围较窄,钙离子交换容量有很大提高.     

利用手持技术改进测定乙醇分子结构实验

利用压强传感器代替排水集气法,改进测定乙醇分子结构实验的仪器装置,并探索最佳反应条件。另外,设计两个空白实验,结合压强变化曲线对实验误差进行相关讨论。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.Novosibirsk Institute of Organic Chemistry, Siberian Branch, Academy of Sciences of the USSR. Translated from Khimiya Prirodynkh Soedinenii, No. 6, pp. 812–816, November–December, 1988.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Calculation of enthalpies of hydrogenation of hydrocarbons

Sets of hydrogen molecule equivalents have been developed which permit the calculation of hydrogenation of different types of carbon-carbon bonds from ab initio total energies (3-21G and 6-31G* basis sets, and, to a more limited extent, for MP2/6-31G* data) of reactants and products. The calculated enthalpies of hydrogenation are in good agreement with experiment for unstrained molecules, with average errors on the order of 2 kcal/mol. The 6-31G* equivalents allow the enthalpies for strained molecules to be calculated accurately, but the 3-21G equivalents do not. The equivalents for both basis sets have been tested by calculating the enthalpies of hydrogenation of carbon-carbon bonds in nitrogen- and oxygen-containing organic molecules, free radicals, and classical carbocations. The results are in good agreement with experiment in most cases.     

光谱仪测试范围的扩展

由于石化行业的生产需要，其材质的使用具有多样性和广泛性，经常会出现顾客委托的测试样品的一个或几个元素跨越光谱仪现有测试程序测量范围的情况。本法通过对光谱仪测试原理的认识，根据光谱仪的测试能力及标样的采集，实现了一个或几个元素测量范围的扩展，并对其测量的影响因素进行了研究。     

Neutral diterpenoids of oleoresins of five species of conifers of Transcarpathia

The compositions of the neutral diterpenoids of the oleoresins of five species of conifers growing in the Transcarpathia have been studied. It has been found that the oleoresins ofAbies alba M.,Larix decidua M., andPicea excelsa L. contain more than 50% of neutral diterpenoids. The group and qualitative compositions of the oxygen-containing diterpenoids have been determined. In the oleoresins ofAbies alba,Picea excelsa, andPicea abies tertiary alcohols — cis-abienol and isocembrol — predominate, while inLarix decidua the main component is the hydroxy ester larixyl acetate. Primary alcohols related to the resin acids have been found in all the oleoresins investigated. Features of the distribution of diterpenoids according to the species of conifers have been revealed. The results obtained are necessary for the chemotaxonomy of conifers of the family Pinceae.     

Influence of viscosity of medium on processes of oxygen quenching of excited states of mesoporphyrin

The oxygen quenching rate constants for singlet and triplet excited states of the dimethyl ester of mesoporphyrin IX increase with decreasing viscosity of the medium and reach a maximum at a viscosity of approximately 0.4 mPa·sec, after which the rate constants begin to decrease. The drop in rate constant with increasing fluidity of the medium may be related to a nonequilibrium character of the elementary act in the interaction of the reactants in the solvent cage. In viscous media such as isopropyl alcohol, isobutyl alcohol, and isoamyl alcohol, the reaction radius is greater than the sum of the radii of the reacting particles. The long-range character of these processes is due to the relatively weak dependence of the quenching probability on distance.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 2, pp. 161–167, March–April, 1989.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.