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171.
Isotherms of the binding of dodecyl sulfate anions (DDS)and Na+ counterions during their coadsorption with a nonionic polymer. proxanol (PR). at the interface of dodecane-water emulsions have been measured by conductometry and Na-selective potentiometry. The adsorption of DDS and PR is concurrent. The affinity constant of PR to the interface determined by the Langmuir model decreases as the concentration of PR increases, and the surface concentration of DDS tends to a nonzero limiting value at high concentrations of PR. The surface (o) and electrokinetic () potentials at the interface have been determined at various polymer concentrations by the spin probe and electrophoresis methods. The average dielectric permeability and density of polymer segments in We adsorption layer have been determined by ESR. The lower boundary of the hydrodynamic thickness of the polymer adsorption layer at the interface has been estimated from the dependences of o and on the ionic strength.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1653–1661, July, 1996.  相似文献   
172.
低分子量聚合物电解质的合成与性能   总被引:4,自引:0,他引:4  
研究了低分子量梳状聚合物电解质的合成方法及结构,性能。首先合成了不同分子量的甲基丙烯酸聚乙二醇单甲醚酯,并进一步合成了分子量一万左右的梳状聚合物电解质,结果表明:反应严格按照反应方程进行,精制产物是非晶的梳状聚合物,本聚合物体系均存在两个玻璃化转变温度,一个在100℃左右,归属为梳状聚合物主链的玻璃化转变,另一个在-20摄氏度以下,归属于侧链玻璃化转变,在室温下侧链可以运动,有利于电活性物质的迁移和扩散,并用超微电极研究了该电解质的行为。  相似文献   
173.
Inclusion of tert-butylbenzeneinto the l-D channel of the titlehost matrix results in a-[CuL2]1/3(tert-butylbenzene)inclusion compound(trigonal, space groupR =3;a = 24.495(3),c = 10.510(2) Å,V = 5461(1) Å3,Z = 9;R = 0.049). The observed guest–host mole ratio of 1/3 was confirmed by X-ray diffraction and arises from the stoichiometric filling of the larger wide segments of the channel. This contrasts with the benzene inclusion compound studied previously, where both the larger and smaller wide segments were occupied to give a 2/3 guest–host stoichiometry. A comparison of these two structures explains the experimental fact that the guest–host mole ratios for inclusions of the title host lie between values of 1/3 and 2/3for 20 different benzene derivatives.  相似文献   
174.
A wholly-aromatic thermotropic liquid crystalline polymer (WATLCP) composed ofp-hydroxybenzoic acid (HBA), 4,4'-dihydroxy bisphenyl (BP), terephthalic acid (TPA),m-phthalic acid (MPA) was synthesized. It was symbolized by BP-LCP. Using a simi-lar method, a new copolymer BP-PSF was prepared. BP-PSF has a semi-flexible chainpolysulfone and a rigid-rod chain like BP-LCP. By FT-IR, polarizing microscope and DSCtechnique, the structures and properties of BP-LCP and BP-PSF were studied.  相似文献   
175.
生物降解聚合物的制备及防肌腱粘连作用   总被引:3,自引:0,他引:3  
  相似文献   
176.
本文合成了二烯丙基二(十二烷基)溴化铵(DADD),用超声波分散其水溶液而形成微泡。用γ射线、偶氮二异丁睛(AIBN)、过硫酸铵(APS)引发使微泡发生聚合,井对所得的微泡进行表征。实验结果证明:用γ射线引发能使微泡双分子膜发生全部聚合、而用AIBN,APS引发则只能发生部分聚合,聚合后,微泡的形状(态),渗透性行为、相转变温度等都未发生变化,但其稳定性却提高了,用断裂电镜证实了本文所合成的微泡是单室的双分子膜微泡。  相似文献   
177.
The first silver(I) complex of saccharinate (sac) with pyridine (py), [Ag(sac)(py)]n has been synthesized and characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffractometry. The complex crystallizes in chiral, trigonal space group P3121 (No. 152) with unit cell parameters of a = 11.2605(2) Å, c = 17.3300(4) Å, V = 1903.02(6) Å3 and Z = 6. [Ag(sac)(py)]n contains monomeric [Ag(sac)(py)] units linked into infinite helices by way of Ag⋅sAg interactions [d(Ag⋅sAg) = 2.909(2) and 2.985(1) Å]. The distorted square-planar environment of Ag is completed by an N-bonded sac [Ag—N = 2.084(2) Å] and a py molecule [Ag—N = 2.116(2) Å]. The Nsac—Ag—Npy angle is 173.85(10). The one-dimensional chains are crosslinked by C—H⋅sO interactions involving the carbonyl and sulfonyl O atoms of sac and aromatic-ring hydrogen atoms of both sac and py. The thermal stability of the title complex was investigated using thermogravimetry and differential thermal analysis in a static atmosphere of air. The first decomposition stage between 90 and 160C corresponds to removal of the py molecule in a single stage, while the degradation of the sac moiety occurs at two stages in the temperature range 370–515C, giving an end product of metallic Ag.  相似文献   
178.
The first TEMPO-mediated "living" free radical polymerization of liquid crystallinemonomer, 2, 5-bis[(4-methoxyphenyl)oxycarbonyl]styrene(MPCS), was carried out at 130℃ withBPO as an initiator. The molecular weight of the polymer can be varied from rather low values to highvalues while maintaining narrow polydispersity. It was observed that the polymerization of MPCSproceeded much faster than that of styrene. A tentative explanation for this fast polymerization wassuggested.  相似文献   
179.
A piezoelectric quartz sensor coated with molecularly imprinted polymer (MIP) for caffeine was developed. The MIP was prepared by co-polymerizing methacrylic acid (MAA) and ethylene glycol dimethacrylate (EDMA) in the presence of azobis(isobutyronitrile) as initiator, caffeine as template molecule, and chloroform as solvent. The MIP suspension in polyvinyl chloride/tetrahydrofuran (6:2:1 w/w/v) solution was spin coated onto the surface of the electrode of a 10 MHz AT-cut quartz crystal. The sensor exhibited a linear relationship between the frequency shift and caffeine concentration in the range of 1×10–7 mg mL–1 up to 1x10–3 mg mL–1 [correlation coefficient (r)=0.9935] in a stopped flow measurement mode. It has a sensitivity of about 24 Hz/ln(concentration, mg mL–1). A steady-state response was achieved in less than 10 min. The performance characteristic of the sensor shows a promising and inexpensive alternative method of detecting caffeine. Surface studies were carried out for the reagent phase of the sensor using SEM, AFM, and XPS analysis in order to elucidate the imprinting of the caffeine molecule. The SEM micrograph, AFM image, and XPS spectra confirmed the removal of caffeine by Soxhlet extraction in the imprinting process and the rebinding of caffeine to the MIP sensing layer during measurement.  相似文献   
180.
以苯乙烯为单体、二乙烯基苯(DVB)为交联剂,过氧化二苯甲酰(BPO)为引发剂研究了蒸馏沉淀聚合法制备聚合物微球过程中交联单体二乙烯苯的用量对单分散聚合物微球成球的影响。结果表明,增加二乙烯基苯的比例,即提高交联度有利于形成单分散的聚合物微球。  相似文献   
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