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671.
Alkylpolyglucosides (C
Y
G
X
) are industrial products of mixtures consisting of a hydrocarbon chain with Y carbon atoms linked to X sugar residues. Based on detailed analytical investigation of technical grade alkylpolyglucosides (C8–10G
X
, C12–14G
X
and C8–16G
X
)/water systems using high-performance liquid chromatography in combination with a special kind of mass spectroscopy their
rheological behaviour is discussed and compared to the rheological behaviour of pure alkyl monoglycosides (C8G1 and C10G1) in water. The rheological properties that exhibit a dependence on the alkyl chain length, Y, and the degree of polymerisation, X, are investigated by rotation and oscillation experiments over an extended concentration range. The Maxwell model fits the
frequency dependence of the dynamic functions fairly well. The viscosity shows an Arrhenius-like dependence on temperature.
A comparison is drawn between the monoglucosides and the polyglucosides, which shows that the rheological properties are more
sensitive to the a change in chain length than in the degree of polymerisation. Phase transitions, especially liquid-crystalline
to isotropic solutions, phase split into two coexisting liquid phases, and could be followed using visual observation and
rheology. Depending on the difference in the rheological properties of the corresponding phases, viscoelastic measurements
showed these transitions clearly. Additionally, the changes in viscosities were measured after addition of a second surfactant.
Received: 4 January 1999 Accepted in revised form: 12 April 1999 相似文献
672.
反相胶束对辣根过氧化物酶催化反应的影响 总被引:3,自引:0,他引:3
胶束体系是酶学研究比较理想的体系,因为它所具有的诸如热力学稳定、光学透明及能增溶亲水分子、亲油分子或两性分子等性质,使许多酶在胶束体系中的反应速率远远高于在水相中,即人们发现的所谓“超活性”[‘j.辣根过氧化物酶(HRP)是一种比较稳定的酶,且价廉易得,具备一般过氧化物酶的典型反应.在研究中人们发现,HRP在反相胶束体系中同样具有“超活性”,由于HRP能够催化大量底物进行反应,因此“超活性”对HRP的催化反应具有重要意义.已有研究者[’、’j对CTAB反相胶束体系中HRP的性质进行了探讨,但反相胶束对HRP的… 相似文献
673.
DDACLB膜的电学性质研究(I)-电导率 总被引:1,自引:1,他引:0
沉积在聚脂基片上的表面软化剂DDAC多分子层,在不同的湿度条件下,其横向导电特性樗该表面活性剂在纤维表面处理过程中驱除静电能力的大小。由原子力显微镜(AFM)图像表明,DDAC的2,4,8多分子层薄膜上的结晶颗粒随层数的增加而增大,因此采用电导率描述基导电性质并借助薄膜电阻加以解释。对复合分子层的电导率的非线性变化除借用了半导体物理学中的渗透理论(Precolatiol Theory)加以解释外, 相似文献
674.
本文综述了近些年来荧光光谱法、顺磁共振(ESR)光谱法和核磁共振(NMR)光谱法在表面活性剂固/液界面吸附研究,尤其是吸附层性质研究中的应用。光谱法是研究吸附层性质的有效手段 相似文献
675.
The past decade has been witness to a new impetus in surfactant self-assembly objects as agents for drug delivery that are an alternative to micellar, lamellar (liposome, niosome and transfersome) or microemulsion-based vehicles. The review focus herein is on the application of hexagonal, cubic, ‘intermediate’ (viz. rhombohedral, tetragonal and monoclinic) and L3 (‘sponge’) mesophases. 相似文献
676.
合成了一个新钌(Ⅱ)表面活性剂配合物[Ru(bpy)2(d19-phen)]Cl2(bpy=2,2′-联吡啶,d19-phen=4,7-二正十九烷基-1,10-邻菲咯啉),用元素分析、核磁共振谱和质谱对配合物的组成和结构进行了表征.该配合物具有优良的发光性能和较高的量子效率,其与水的混合体系展示良好的溶致液晶行为. 相似文献
677.
678.
The lytic interactions of a series of alkyl glucosides (alkyl chain lengths ranging from C8 to C12) with liposomes formed by a mixture of lipids modeling the stratum corneum (SC) lipid composition were investigated. The
surfactant-to-lipid molar ratios (Re) and the normalized bilayer/aqueous phase partition coefficients (K) were determined by monitoring the changes in the static light-scattering (SLS) of the system during solubilization. The
fact that the free surfactant concentrations were always similar to their critical micelle concentrations indicates that the
liposome solubilization was mainly ruled by the formation of mixed micelles. At the two interaction levels studied (100 and
0% SLS) the nonyl glucoside showed the highest ability to saturate and to solubilize liposomes (lowest Re values), whereas
the dodecyl glucoside showed the highest degree of partitioning into liposomes or affinity with these structures (highest
K values). Comparison of the data for octyl glucoside with that reported for the interaction of this surfactant with phosphatidylcholine
(PC) liposomes shows that whereas the SC lipid liposomes were more resistant to the action of this surfactant (higher Re values),
its degree of partitioning into SC bilayers was both in the saturation and solubilization of liposomes similar to that exhibited
in PC vesicles (similar K values).
Received: 27 November 2000/Accepted: 19 February 2001 相似文献
679.
Interactions between a polymer and a surfactant were studied via surface tension measurements. Poly(ethylene glycol) and
sodium dodecyl sulfate were used as a polymer and a surfactant, respectively. The addition of polymer affected the CMC value
of the surfactant. The interpretations of the data and theoretical plots of polymer-surfactant interactions are discussed
using a theoretical model.
Received: 28 September 2000 Accepted: 3 October 2000 相似文献
680.
WANG Zhi QUAN Jing WENG Liang ZHENG Liang-yu LIU Ning DONG Huan CAO Shu-gui ** . Key Laboratory for Molecular Enzymology Engineering of Educational Ministry . College of Life Science Jilin University Changchun P. R. China 《高等学校化学研究》2003,19(4):446-449
IntroductionThe demand for the high purity of chiral com-pounds has led to the increasing use of biocatalystsand the increasing research in order to obtain en-zymes with a higher activity and selectivity.In thisfield the utilization of lipases has been proved to beone of the simplest but most promising techniquesfor the enantioselective conversion of various hy-drophobic acids and alcohols in the last decade.There has been a considerable interestin improvingthe enantioselectivity of lipases an… 相似文献