排序方式: 共有57条查询结果,搜索用时 109 毫秒
51.
Ishihara Y Bazzi HS Toader V Godin F Sleiman HF 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(16):4560-4570
Ring-opening metathesis polymerization was used to generate an ABC triblock copolymer, containing complementary diamidopyridine (DAP) and thymine (THY) outer blocks, which assembles into spherical aggregates held together by DAP-THY noncovalent interactions. Addition of THY-containing small guest molecules results in complete opening and deaggregation of the block copolymer micelle. This molecular recognition and macroscopic response shows high selectivity to the guest structure, and tolerates only a small amount of conformational mobility in the THY guest. On the other hand, addition of a small DAP-containing guest does not break the aggregates, but instead, results in new micelles which show a different selectivity profile from the parent morphology. We have examined the effect of a number of structural features in the block copolymers, on both the extent and selectivity of their macroscopic response to guests (that is, opening of the micelle). This study has resulted in a set of structural guidelines, which help in the design of effective molecule-responsive micelles for applications in selective drug delivery, sensing, and surface patterning. 相似文献
52.
Mohammed Al‐Hashimi Chayanant Hongfa Beena George Hassan S. Bazzi David E. Bergbreiter 《Journal of polymer science. Part A, Polymer chemistry》2012,50(19):3954-3959
Polyisobutylene‐supported second‐generation Hoveyda‐Grubbs catalyst is shown to be an effective nonpolar phase tag for ring‐opening metathesis polymerization (ROMP). The catalytic activities of the supported Ru–carbene complex in ROMP are comparable to those of their homogeneous counterparts. The separability of these catalysts leads to lower Ru contamination (0.5 ppm levels) in the polymer products in comparison to the nonsupported Hoveyda‐Grubbs catalyst (10 PPM). © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
53.
Leila Afia Rachid Salghi El Houcine Bazzi Abdelkader Zarrouk Belkheir Hammouti Mohamed Bouri Hassan Zarrouk Lahcen Bazzi Lahcen Bammou 《Research on Chemical Intermediates》2012,38(8):1707-1717
Argan hulls extract (AHE) was tested as corrosion inhibitor for mild steel in 1?M HCl. Weight loss measurements, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) revealed that inhibiting action increased with increasing concentration of the inhibitor. The highest efficiency 97.3% was obtained at 5?g/L AHE. There was good agreement between gravimetric and electrochemical methods (potentiodynamic polarization and EIS). Results obtained from EIS measurements were analyzed to model the corrosion-inhibition process by use of the appropriate equivalent circuit model; a constant phase element was used. Polarization measurements show also that AHE acts as good mixed inhibitor. AHE is adsorbed on the steel surface in accordance with a Langmuir isotherm adsorption model. 相似文献
54.
A method for the determination of traces of silicate based on the use of a strong base anion exchange in a preconcentration step and a batch-reactive stripping agent technique prior to spectrophotometric determination has been proposed. The reaction of molybdate and silicate in acidic solution to form 12-molybdosilicic acid permits recoveries exceeding 90% in analyzing solutions containing 0.02 to 0.1 μg of silicon/ml. 相似文献
55.
M.A. Flores-González C. Louis R. Bazzi G. Ledoux K. Lebbou S. Roux P. Perriat O. Tillement 《Applied Physics A: Materials Science & Processing》2005,81(7):1385-1391
Red-emitting Eu3+-doped Gd2O3 spherical powders were directly precipitated using a polyol method. The as-synthesized powders consist of agglomerates with a spherical shape and a size ranging between 0.4 and 0.6 μm. Each agglomerate is nanostructured and consists of a packing of nanocrystallites (3–5 nm) of a bcc oxide phase whose luminescence presents original features in comparison with bulk materials. The powders were further calcinated and the size of both crystallites and agglomerates, the crystalline structure and the luminescence were studied as a function of the annealing temperature. For temperatures lower than 900 °C, the samples obtained are highly crystalline and possess the classical Eu3+ red luminescence. For optimized temperature, the morphology of the particles can be preserved leading to spherical, dense, luminescent and almost monodisperse oxide powders, 0.5 μm in size. PACS 81.07.Bc; 81.07.Wx; 81.16.Be; 75.50.-y; 42.70.-a 相似文献
56.
Sulfines react with sulfinyl chlorides giving α-chloroalkyl alkanethiosulfonate esters and with thionyl chloride giving α-chloroalkanesulfenyl chlorides, both in good yields. 相似文献
57.
Dris Ben Hmamou Rachid Salghi Abdelkader Zarrouk Hassan Zarrouk Mohamed Errami Belkheir Hammouti Laila Afia Lhoucine Bazzi Lahcen Bazzi 《Research on Chemical Intermediates》2013,39(3):973-989
The inhibitive action of verbena essential oil (VEO) on the corrosion of mild Steel in 1 M HCl solutions in the temperature range 298 to 328 K was measured by use of the weight-loss method, potentiodynamic polarization, and electrochemical impedance spectroscopy. Results showed that VEO inhibited corrosion of C38 steel in 1 M HCl solution and that inhibition efficiency increased with increasing concentration of inhibitor but decreased proportionally with temperature. Potentiodynamic polarization studies suggested VEO is a mixed-type inhibitor, with the anodic type predominating. Nyquist plots were depressed semicircles with their centre below the real axis. Adsorption of VEO by the C38 steel surface followed the Langmuir adsorption isotherm. Kinetic data for dissolution were investigated. 相似文献