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81.
Nitin S. Patil Yanzi Li David G. Rethwisch Jonathan S. Dordick 《Journal of polymer science. Part A, Polymer chemistry》1997,35(11):2221-2229
A series of degradable hydrogels based on different vinyl monomers such as acrylamide, sucrose-1′-acrylate, and acrylic acid were synthesized using sucrose-6,1′-diacrylate (SDA) as a crosslinking agent. SDA was prepared by enzymatic transesterification of vinyl acrylate with sucrose in pyridine. Base catalyzed hydrolysis of SDA in aqueous solution was studied as a function of pH. As expected, hydrolysis of SDA was faster at higher pHs such that poly(acrylamide), poly(sucrose 1′-acrylate), and poly(acrylic acid) hydrogels underwent substantial degradation at and above pH 7, 9, and 13, respectively. The degradation was characterized by changes in the swelling ratios of the hydrogels indicating breakage of the crosslinking agent. Degradation of the hydrogels at their chemically stable pHs was studied in presence of enzymes. Enzymes, including pepsin and a fungal Lipase, were able to degrade the poly(acrylamide) hydrogel at pH 4 and 5, respectively. Poly(acrylic acid) hydrogel was degraded in presence of a fungal protease at pH 7.8. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2221–2229, 1997 相似文献
82.
Formation of C(sp2)–X bonds was carried out using a Fe3O4@SiO2‐copper(I) sucrose xanthate nanoparticle catalyst with the aid of the copper(I) xanthate moiety in the catalyst which was prepared from the reaction between sucrose and carbon disulfide through an alkaline medium via the traditional Zeise approach. Various techniques were employed for the characterization of these novel nanoparticles. Three sorts of heteroatoms, N, O and S, successfully underwent heteroatom arylation to produce secondary or tertiary amines, ethers and thioethers, respectively. 相似文献
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BF3‐grafted Fe3O4@Sucrose nanoparticles as a highly‐efficient acid catalyst for syntheses of Dihydroquinazolinones (DHQZs) and Bis 3‐Indolyl Methanes (BIMs) 下载免费PDF全文
Iman Radfar Maryam Kazemi Miraki Leila Ghandi Naghmeh Esfandiary Sepideh Abbasi Meghdad Karimi Akbar Heydari 《应用有机金属化学》2018,32(8)
Current paper represents immobilization of sucrose on the Fe3O4 core and grafting of boron trifluoride (BF3) onto the new surface. The catalytic activity of these nanoparticles was tested in syntheses of Dihydroquinazolinones (DHQZs) and Bis (3‐Indolyl) Methanes (BIMs) as two fruitful pharmaceutical structures. Acidic capacity, FT‐IR, XRD, VSM, TGA and SEM–EDX tests are carried out on such novel nanoparticles (NPs). Catalyst has shown more acidic capacity per one gram of NPs than sulfonated homologue which was reported previously. 相似文献
86.
该文以更加接近生物矿化的方法研究了蔗糖/精氨酸体系对碳酸钙晶体取向、形貌和晶型的控制作用.XRD 分析表明,在蔗糖/L-精氨酸混合体系中合成的晶体主要为碳酸钙的球霰石晶型及少量的方解石型,在单独的蔗糖或L-精氨酸溶液中基本是球霰石晶型.SEM分析表明,蔗糖和L-精氨酸均可诱导形成特殊形貌的碳酸钙.实验结果表明,蔗糖/精... 相似文献
87.
A spin-echo technique is employed to produce high quality in vitro19F magnetic resonance images using vesicles of a highly fluorinated sucrose octaester. The results hold promise for in vivo imaging of the gastrointestinal tract. 相似文献
88.
YuKE MinLIU ZhenZhongLIU 《中国化学快报》2004,15(3):273-274
2,6-Di-O-acetyl sucrose was regioselective synthesized by using dibutyltin oxide in about 60% yield. The structure of acetyl derivative was elucidated by ^1H NMR, ^13C NMR,2D-NMR and MS spectral data. 相似文献
89.
Victoria Klang Anna Novak Michael Wirth 《Journal of Dispersion Science and Technology》2013,34(3):322-333
Sucrose stearate blends of intermediate lipophilicity are mild surfactants with thermosensitive gelling behavior. Binary systems and emulsions with sucrose stearate S-970 or S-1170 were developed and investigated by thermoanalytical and rheological measurements. The presence of an oil phase promoted the gelling potential of the esters especially at higher production temperatures. Semi-solid emulsions with viscoelastic properties comparable to weak gels were obtained with different dermatologically acceptable oils. The complex internal structure as visualized by fluorescence microscopy exhibited changes during storage in dependence of oil and surfactant type. A combination of S-970 with cetearyl ethylhexanoate-based oil phases led to superior physical stability. 相似文献
90.
Frederick G. Vogt Alan J. Benesi 《Journal of magnetic resonance (San Diego, Calif. : 1997)》1998,132(2):214-219
Two1H-detected one-dimensional gradient enhanced experiments and corresponding reference experiments are proposed for the measurement of heteronuclear long-rangenJCHcoupling constants in organic molecules. These experiments use inverse detection and selective carbon excitation, provide excellent suppression of protons not coupled to13C, and are able to measure couplings from regions that are crowded in both the proton and carbon frequency ranges. The experiments are applied to determine the long-rangenJCHcouplings in the sucrose molecule, including coupling across the glycosidic linkage. These pulse sequences are shown to provide accurate and efficient measurements of coupling constants that would be difficult or time-consuming to measure by other techniques. 相似文献