压裂液用有机硼锆交联剂OBZ－1

本文介绍了一种新型压裂液用交联剂——有机硼锆交联剂ＯＢＺ－１。该交联剂具有较强的耐温性及抗剪切性能，对地层的伤害较轻。讨论了该剂的交联机理     

Ionic conductivity of polymer gels deriving from alkali metal ionic liquids and negatively charged polyelectrolytes

We have prepared polymer gel electrolytes with alkali metal ionic liquids (AMILs) that inherently contain alkali metal ions. The AMIL consisted of sulfate anion, imidazolium cation, and alkali metal cation. AMILs were mixed directly with poly(3-sulfopropyl acrylate) lithium salt or poly(2-acrylamido-2-methylpropanesulfonic acid) lithium salt to form polymer gels. The ionic conductivity of these gels decreased with increasing polymer fraction, as in general ionic liquid/polymer mixed systems. At low polymer concentrations, these gels displayed excellent ionic conductivity of 10⁻⁴ to 10⁻³ S cm⁻¹ at room temperature. Gelation was found to cause little change in the diffusion coefficient of the ionic liquid, as measured by pulse-field-gradient NMR. These data strongly suggest that the lithium cation migrates in successive pathways provided by the ionic liquids.     

Preliminary report of the discovery of a new pharmaceutical granulation process using foamed aqueous binders

Spray granulation is commonly used to improve the flow of drug formulation powders by adding liquid binders. We have discovered a new granulation process whereby liquid binders are added as aqueous foam. Initial experiments indicate that foam granulations require less binder than spray granulations, less water is added to the powder mass, rates of addition of foam can be greater than rates of addition of sprayed liquids, and foam can be added in a single batch to the surface of the powder mass for incorporation at some later stage in the process. This new process appears to have no detrimental effects on granulate, tablet, or in vitro drug dissolution properties. In addition, the elimination of spray addition reduces the complexity of the process and avoids the plugging problems associated with spray nozzles. Several formulations were successfully scaled up from laboratory scale (1.5 kg) to pilot scale (15 kg). Process control was good and there was no detrimental effect on tablet and drug dissolution properties. This paper also proposes a working hypothesis of the mechanism by which foam granulation operates.     

Thiols as chain transfer agents in free radical polymerization in aqueous solution

The behavior of thiophenol and aliphatic thiols of different structure as chain transfer agents in the polymerization of acrylamide and 1-vinyl-2-pyrrolidone in aqueous solution at 25 °C was studied. Addition of millimolar concentrations of thiols to acrylamide polymerization reduced notably the polymer molecular weights, without change of the polymerization rate. Measurements at different pH showed that the reactive species towards the macroradicals is the protonated -SH group. Chain transfer constants, determined from Mayo plots, are only slightly dependent on the thiol structure. Aliphatic thiols and thiophenol react at similar rates. The selectivity is opposite for acrylamide (electron acceptor) and 1-vinyl-2-pyrrolidone (electron donor), pointing to significant charge transfer contributions. The reactions rates of these sulfur compounds with the electrophilic DPPH radical showed higher selectivity, and are not related with the chain transfer constants measured for the acrylamide macroradicals. These results are explained in terms of the different factors that control the reactivity of thiols with macroradicals.     

Non-absorbable gas effects on heat and mass transfer in falling film absorption

Film absorption involves simultaneous heat and mass transfer in the gas-liquid system. While the non-absorbable gas does not participate directly in the absorption process, its presence does affect the overall heat and mass transfer. An experimental study was performed to investigate the heat and mass transfer characteristics of LiBr-H₂O solution flowing over 6-row horizontal tubes with the water vapor absorption in the presence of non-absorbable gases. The volumetric concentration of non-absorbable gas. air, was varied from 0.17 to 10.0%. The combined effects of the solution flow rate and its concentration on the heat and mass transfer coefficients were also examined. The presence of 2% volumetric concentration of air resulted in a 25% reduction in the Nusselt number and 41% reduction in the Sherwood number. Optimum film Reynolds number was found to exist at which the heat and mass transfer reach their maximum value independent of air contents. Reduced Nusselt and Sherwood numbers, defined as the ratio of Nusselt and Sherwood numbers at given non-absorbable gas content to that with pure water vapor, were correlated to account for the reduction in the heat and mass transfer due to non-absorbable gases in a falling film absorption process.     

溶胶-凝胶法制备ITO薄膜研究进展

概述了近年来国内外溶胶-凝胶法(Sol-Gel)制备ITO薄膜的研究状况,对Sol-Gel法制备ITO薄膜工艺做了简要介绍,重点讨论了Sol-Gel法制备ITO薄膜的溶胶体系,分析比较了有机醇盐、无机盐以及掺入ITO粉末方法体系的优缺点,最后讨论了甩膜法、提拉法及平铺法在Sol-Gel法制备ITO薄膜中镀膜的应用.指出Sol-Gel法是一种高效可行的制备ITO薄膜的方法,有着广阔的应用前景.     

Thermal, Optical, and Electrical Properties of Gel Grown ZMTC

The bimetallic thiocyanate of the group IIB divalent d¹⁰ ions Zn²⁺ and Hg²⁺ having unique characteristics: The pale color and high thermal stability—Zinc Mercury tetrathiocyanate (ZMTC) is chosen for growth and study. ZMTC is grown in silica gel by chemical reaction method and characterized by single crystal XRD, FTIR, FT-Raman, UV-Vis-NIR, NLO, TGA/DTG, DSC, AC conductivity, and dielectric studies. It has wide transparency window and possesses high second harmonic generation efficiency. Its thermal stability is very high. The dielectric permittivity of this material is very low.     

Elucidation of interactive effects of synthesis conditions on the characteristics of mesoporous silicas templated using polyoxide surfactant

A series of mesoporous silicas (MS-1-MS-9) were synthesized at different gel compositions using a triblock copolymer (TCP), poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide), as the surfactant. The interactive effects of acidity, the contents of tetraethyl orthosilicate (TEOS) and the surfactant, and the gelling temperature on the characteristics of the final material were simultaneously characterized. Increasing acidity favored mesopore formation. A material with a surface area of 760 m²/g, mostly in the mesoporous range, was obtained at 1.0(TEOS):0.017(TCP):7.3HCl:115.7H₂O. Mesopore formation was predominantly determined by the TEOS:TCP ratio and was promoted with its increase from 1.56:1 to 2.09:1. A further increase to 2.61:1 was detrimental. Whereas increasing the TCP content to 3.5% w/w improved micellization, a further increase to 4.6% should be avoided. Mesoporous silicas showed low crystallinity but a high degree of hexagonal mesoscopic organization. The weak surface acidity was attributed to surface silanols, the number of which was proportional to mesoporosity.     

Thermal Conductivity of Aqueous Sugar Solutions under High Pressure

Molecular energy transport in aqueous sucrose and glucose solutions of different mass fractions and temperatures is investigated up to 400 MPa, using the transient hot-wire method. The results reveal an increasing thermal conductivity with increasing pressure and decreasing mass fraction of sugar. No significant differences between sucrose and glucose solutions were observed. Different empirical and semi-empirical relations from the literature are discussed to describe and elucidate the behavior of the solutions with pressure. The pressure-induced change of the thermal conductivity of sugar solutions is mainly caused by an increase of the thermal conductivity and the decrease of molar volume of the water fraction. A simple pressure adapted mass fraction model permits an estimation of the thermal conductivity of the investigated solutions within an uncertainty of about 3%. An erratum to this article can be found at