羧酸聚合物对磷酸钙的阻垢作用和机理

采用静态阻垢法评定了膦酰基羧酸聚合物(POCA)、聚丙烯酸(PAA)、丙烯酸-丙烯酸羟丙酯共聚物(T-225)、水解聚马来酸酐(HPMA)等四种羧酸类聚合物阻垢剂对磷酸钙的阻垢性能, 发现在加药量为25 mg/L时几种聚合物对磷酸钙垢的阻垢率分别为100%, 94.6%, 36.2%和30.2%. 采用分子动力学(MD)方法, 模拟计算了四种聚合物与磷酸钙晶体的(110)晶面的相互作用结合能、非键作用能等参数. 结果表明: 聚羧酸与(110)晶面结合能以及非键作用能的大小排序为POCA＞T-225＞HPMA＞PAA, 结合能以及非键作用能越大, 说明聚合物与垢晶体的结合越紧密, 抑制性能越好; 因此它们对磷酸钙阻垢能力大小排序为POCA＞T-225＞HPMA＞PAA. 该理论计算与实验室静态阻垢评定结论一致. 通过对超分子对关联函数的分析, 发现POCA和T-225聚合物中羰基O原子与晶面上Ca^2＋之间形成了较弱的离子键, 但强度远比非键作用小, 非键作用主要由库仑作用和范德华作用力提供, 且库仑作用的贡献更大. 据此合成了马来酸酐-苯乙烯磺酸钠-丙烯酸羟丙酯(MA-SS-HPA)以及苯乙烯磺酸钠-丙烯酸羟丙酯-亚磷酸(MA-SS-H₃PO₃)共聚物, 加药量为18 mg/L时对磷酸钙垢的阻垢率分别为94.2%和100%, 性能优于POCA.     

羧酸共聚物与方解石晶体相互作用的MD模拟

用分子动力学方法, 模拟计算了丙烯酸-丙烯酸甲酯共聚物(AA-MAE)、丙烯酸-丙烯酸羟丙酯共聚物(AA-HPA)、丙烯酸-马来酸共聚物(AA-MA)及水解马来酸酐(HPMA)四种聚羧酸类阻垢剂与方解石晶体(110)晶面的相互作用. 结果表明, 聚羧酸与(110)晶面结合能的大小排序为AA-MA＞HPMA＞AA-HPA＞AA-MAE; 对体系各种相互作用以及径向分布函数的分析表明, 结合能主要由库仑作用(包括离子键)提供, 并含少量氢键成分. 与方解石晶面结合的聚合物发生扭曲变形, 但形变能远小于相应的非键作用能. 聚合物中不同位置羧基的动力学行为差别很大, 链端羧基的运动翻转比链中部羧基剧烈得多, 故后者与晶面的结合比前者更牢固而具有更强的阻垢能力.     

水溶性聚合物与硬石膏晶体相互作用的分子动力学模拟

用分子动力学(MD)方法, 模拟计算了6种水溶性聚合物阻垢剂{聚丙烯酸(PAA)、聚甲基丙烯酸(PMAA)、丙烯酸-丙烯酸甲酯共聚物[P(AA-co-MAE)]、丙烯酸-丙烯酸羟丙酯共聚物[P(AA-co-HPA)]、聚马来酸(HPMA)、丙烯酸-马来酸共聚物[P(AA-co-MA)]}与硬石膏晶体的相互作用. 结果发现, 聚合物与硬石膏晶体结合能的大小排序为P(AA-co-MA)＞HPMA＞P(AA-co-HPA)＞P(AA-co-MAE)＞PMAA＞PAA, 同种聚合物阻垢剂对硬石膏两晶面生长的抑制能力相差不大. 对体系各种相互作用以及对关联函数g(r)的分析表明, 体系结合能主要由库仑作用提供. 与硬石膏晶体结合的聚合物发生明显形变, 但形变能远小于体系的非键作用能. 聚合物中不同位置羧基的动力学行为差别很大, 链端羧基的运动翻转比链中部羧基剧烈得多, 因后者与硬石膏晶体的结合比前者牢固而能更有效地抑制垢晶体生长.     

水溶性聚合物与方解石晶体相互作用的MD模拟

用分子动力学(MD)方法, 模拟计算了三种水溶性聚合物阻垢剂[聚丙烯酸(PAA)、聚甲基丙烯酸(PMAA)、丙烯酸-丙烯酸甲酯共聚物(AA-MA)]与方解石晶体的作用. 结果表明, 聚合物与方解石两晶面结合能的大小均为PAA ＞ AA-MA ＞ PMAA, 聚合物与(1 0)面的相互作用远比与(104)面的作用强. 对体系各种相互作用以及对关联函数g(r)的分析表明, 结合能主要由库仑作用决定. 与方解石晶面结合的聚合物发生扭曲变形, (1 0)面上的形变能约为(104)面上的2倍, 但均远小于相应的非键作用能. 聚合物中不同位置羧基的动力学行为差别很大, 链端羧基的运动翻转比链中部羧基剧烈得多, 后者与方解石晶体的结合比前者牢固而能更有效地抑制垢晶体生长.     

聚天冬氨酸与聚丙烯酸等复合药剂的协同性能研究

在碱性条件下,聚琥珀酰亚胺(Polysuccimide, PSI)发生开环反应,经洗涤干燥制得天冬氨酸聚合物(PASP),并用~1H NMR对其结构进行表征,采用静态阻垢、旋转挂片等方法考察其阻垢、缓蚀性能.通过正交试验讨论PASP与聚丙烯酸(PAA)、ZnSO_4、2-膦酸基丁烷-1,2,4-三羧酸(PBTCA)的协同性能与作用机理,结果表明:当PASP、PAA、ZnSO_4、PBTCA浓度分别为40、30、4、8 mg/L时,其阻碳酸钙垢率可达95.04%,缓蚀率可达90%,表现出优秀的协同增效性能.该复合药剂绿色、低磷、高效,具有较好的应用前景.     

膦系阻垢剂对碳酸钙阻垢机理的研究

在模拟循环水中,通过静态阻垢实验研究了HEDP,PBTCA,ATMP和EDTMP对碳酸钙的阻垢性能,在相同的加药浓度下(按物质的量浓度计)阻垢性能的强弱顺序为HEDPPBTCAATMPEDTMP;同时采用分子动力学方法,模拟计算了阻垢剂负二价离子与方解石(104),(102),(202)和(113)面的相互作用.结果表明:阻垢剂分子中的膦酸基团和羧酸基团与碳酸钙中的Ca2+形成的离子键对吸附起到了主要作用,同时阻垢剂与晶面间存在较弱的范德华力相互作用.阻垢剂与各晶面的结合能强弱顺序为(113)≥(102)≥(202)(104);分子中的羟基易与垢晶面形成氢键而加强阻垢效果;羧基的位置不同对阻垢作用的影响不同.将静态阻垢的实验结果与分子动力学模拟结果进行了相关性分析,发现阻垢剂在(104)面和(102)面上的吸附对阻垢作用的贡献较大.     

聚羧酸类超塑化剂分子结构对石膏分散性能的影响

研究了甲基丙烯酸-甲氧基聚乙二醇甲基丙烯酸酯(MAA-MPEGMA)、甲基丙烯酸-烯丙基聚乙二醇醚(MAA-APEG)、丙烯酸-烯丙基聚乙二醇醚(AA-APEG)三类梳形聚羧酸类接枝共聚物以及丙烯酸均聚物(PAA)对石膏粉体分散性能和凝结时间的影响.聚合物侧链长度越短、分子量越小、电荷密度越高对石膏的分散性能越好,同时...     

膦系阻垢剂阻碳酸钙垢机理的研究

在模拟循环水中, 通过静态阻垢实验研究了HEDP, PBTCA, ATMP和EDTMP对碳酸钙的阻垢性能, 在相同的加药浓度下(按物质的量浓度计)阻垢性能的强弱顺序为HEDP＞PBTCA＞ATMP＞EDTMP; 同时采用分子动力学方法, 模拟计算了阻垢剂负二价离子与方解石(104), (102), (202)和(113)面的相互作用. 结果表明: 阻垢剂分子中的膦酸基团和羧酸基团与碳酸钙中的Ca^2＋形成的离子键对吸附起到了主要作用, 同时阻垢剂与晶面间存在较弱的范德华力相互作用. 阻垢剂与各晶面的结合能强弱顺序为(113)≥(102)≥(202)＞(104); 分子中的羟基易与垢晶面形成氢键而加强阻垢效果; 羧基的位置不同对阻垢作用的影响不同. 将静态阻垢的实验结果与分子动力学模拟结果进行了相关性分析, 发现阻垢剂在(104)面和(102)面上的吸附对阻垢作用的贡献较大.     

含荧光基团的AA-MA共聚物阻垢剂的合成及其阻垢性能

以4-溴-1,8-萘二甲酸酐和乙二胺为原料,经3步反应合成了一种新型荧光单体——4-甲氧基-N-(2-丙烯酰胺乙基)-1,8-萘二酰亚胺(Ⅲ);Ⅲ与丙烯酸(AA)和马来酸酐(MA)共聚制得新型示踪共聚物AA-MA-Ⅲ(1),其结构经IR,TG-DTA和SEM表征。1的荧光性质和阻垢性能研究结果表明,其荧光强度与质量浓度呈良好线性关系,线性相关系数为0.998 5,检测下限为1.0×10-2mg.L-1;1对碳酸钙垢沉积有较好的抑制作用,当用药量为20 mg.L-1时对碳酸钙阻垢率为93.5%,且具有较好的分散氧化铁的能力;SEM观察表明1对碳酸钙垢既有较强的分散作用又具有明显的晶格畸变作用。     

膦酰基羧酸调聚物对硫酸钙的阻垢机理

静态阻垢法试验表明,膦酰基羧酸聚合物(POCA)对硫酸钙垢沉积具有优异的抑制作用,当加药量为5mg/L时阻垢率达到100%,投加POCA前后硫酸钙表观形貌的变化的扫描电镜分析证实,POCA对垢晶体具有强烈的扭曲畸变作用,随着加药浓度的提高,POCA对晶面的畸变作用增强.采用分子动力学(MD)模拟,计算了POCA与硫酸钙晶体的最主要生长面(020)和主要生长面(010)晶面的相互作用,对体系各种相互作用的分析表明,POCA在与硫酸钙晶体结合过程中其结合能远大于常规吸附能,使其容易占据晶体的活性生长点而使品格发生畸变 POCA对(020)晶面的作用比对(010)晶面的强 超分子体系的作用能主要由库仑作用提供.     

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.     

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。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

解决能源问题的新途径--光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。