检索结果-南通市图书馆

EFFECT OF ORTHO-METHOXYCINNAMIC ACID ON THE SOL-GEL TRANSITION OF METHYLCELLULOSE SOLUTIONS IN THE PRESENCE OF cetyltrimethylammonium bromide

引用

Chinese Journal of Polymer Science 2013年第2期31卷 263-274页

作者： Jun Tao 杨海洋 Xiang Hao Yong-jun Xie Hua-yu Li School of Chemistry and Materials Science University of Science and Technology of China

The sol-gel transition of methylcellulose （MC） solutions in the presence of ortho-methoxycinnamic acid （OMCA） or cetyltrimethylammonium bromide （CTAB） and in the coexistence of OMCA and CTAB was determined by the rheological measurement. It has been found that the sol-gel transition temperature of MC solutions increases linearly with the concentration of either OMCA or CTAB in solution, respectively. However, in the coexistence of OMCA and CTAB, the sol-gel transition temperature of MC solutions remains invariable, independent of the concentration of CTAB in solution. The experimental results show that OMCA has priority to adsorb on the methyl group of MC chains to form polymer-bound aggregates. In particular, these aggregates inhibit the hydrophobic interaction between CTAB and the methyl group of MC chains completely. Taking into account the fact that OMCA is almost insoluble in MC-free solutions but dissolves very well in aqueous MC solutions, we propose the formation of the core-shell architecture prompted by OMCA and the methyl group of MC chains, with the methyl group of MC chains serving as the core and the self-assembly of OMCA molecules serving as the shell. Obviously, the formation of the core-shell structure increases the solubility of OMCA, improves the stability of methyl groups of MC chains at high temperatures and inhibits the hydrophobic interaction between CTAB and the methyl group of MC chains in solution. The abnormal behavior relating to the sol-gel transition of MC solutions in the presence of OMCA or in the coexistence of OMCA and CTAB is therefore explained. Upon UV irradiation, the sol-gel transition temperature of MC solutions in the presence of OMCA, or in the coexistence of OMCA and CTAB, decreases notably. However, the dependence of the sol-gel transition temperature of MC solutions as a function of OMCA concentration, or CTAB concentration in the presence of OMCA, does not change after UV irradiation.

关键词： Methylcellulose Ortho-methoxycinnamic acid cetyltrimethylammonium bromide Sol-gel transition Hydrophobic interaction.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Influence of Low cetyltrimethylammonium bromide Concentration on the Interactions and Properties of Hemoglobin with Acyclovir

引用

Chinese Journal of Chemistry 2006年第5期24卷 620-626页

作者：刘天睛郭荣 School of Chemistry and Chemical Engineering Nanjing University Jiangsu 210093 China School of Chemistry and Chemical Engineering Yangzhou University Yangzhou Jiangsu 250002 China

The effects of cetyltrimethylammonium bromide （CTAB） on the properties of hemoglobin （Hb） at low CTAB concentration were studied in Hb/acyclovir/CTAB system by the methods of UV-Vis spectrum, fluorescence, zeta potential, conductivity and negative-staining transmission electron microscope （TEM）. With the increase of CTAB concentration, the UV peak intensity at 276 nm, the intrinsic fluorescence, the zeta potential of Hb and the system conductivity were all enhanced. Hb was easily oxidized to oxyHb and hemichrome. In Hb/acyclovir/CTAB system, CTAB made the UV-Vis spectrum, fluorescence, conductivity and conformation of Hb tend to be returned to those of the original Hb but the zeta potential not to do so. The UV absorption peak of Hb-acyclovir complex disappeared and the tight structure of Hb aroused by acyclovir was refolded. When CTAB concentration was higher than 5 × 10 ^5 mol/L, the two absorption peaks at 536 and 576 nm appeared again, and the Hb structure became looser again.

关键词： hemoglobin cetyltrimethylammonium bromide acyclovir property interaction

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Novel Approach to Characterization of Rare Earth Complexation with 1, 5-Bis(2-Hydroxy-5-Chlorphenyl)-3-Cyanoformazan in Presence of cetyltrimethylammonium bromide

引用

Journal of Rare Earths 2002年第5期20卷 525-532页

作者：郑立新胡张军郜洪文 Anhui Univ Sch Chem & Chem Engn Hefei 230039 Peoples R China

The ternary interaction of 1, 5 bis(2 hydroxy 5 chlorphenyl) 3 cyanoformazan (HCPCF) with cetyltrimethylammonium bromide (CTAB) and rare earths (RE: Yb, Dy, Er and Eu) was investigated at pH 9.84 by the microsurface adsorption spectral correction technique (MSASC). The aggregation of HCPCF on CTAB obeys the Langmuir isothermal adsorption and the interaction of RE with the HCPCF CTAB aggregate was first found to accord with the monolayer binding. The effects of temperature and ionic strength of solution on the aggregations were made. The binary aggregate and the ternary complex were characterized.

关键词： rare earths microsurface adsorption spectral correction technique langmuir aggregation cetyltrimethylammonium bromide 1,5 bis(2 hydroxy 5 chlorphenyl) 3 cyanoformazan ternary complex

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Cu(Ⅱ),Ni(Ⅱ)Complexation with Acid Alizarine Blue B in the Presence of cetyltrimethylammonium bromide

引用

Chinese Journal of Chemical Physics 2006年第2期19卷 178-182页

作者：沈荣郜洪文俞汉青安徽职业技术学院化工系合肥230051 同济大学环境科学与工程学院"长江水环境"教育部重点实验室上海200092 中国科学技术大学化学系合肥230026

The coordination reactions of Cu（Ⅱ） and Ni（Ⅱ） with acid alizarine blue B （AABB） in the presence of cetyltrimethylammonium bromide （CTAB） micelle were investigated using the microsurface adsorptionspectral correction technique （MSASC）. The aggregation of AABB on CTAB followed the Langmuir isothermal adsorption law. The enrichment of AABB on CTAB sensitized the complexation between Cu（Ⅱ） or Ni（Ⅱ）and AABB. The binding ratio of AABB to CTAB was 1：2.5, and monomeric aggregate, AABB2CTAB5, was formed with an adsorption constant of 5.95×10^5 at 20 ℃ or 2.48×10^5 at 40 ℃. In the ternary complexation, the ratio of AABB：Cu and AABB：Ni were 1：1 and 1：2.5, respectively. Two types of aggregates, ***2·CTAB80 and ***80, were formed.

关键词： Microsurface adsorption-spectral correction technique Langmuir aggregation Acid alizarine blue B cetyltrimethylammonium bromide Ternary complex

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of cetyltrimethylammonium bromide on morphology and porous structure of mesoporous hydroxyapatite

引用

Transactions of Nonferrous Metals Society of China 2015年第2期25卷 483-489页

作者：王晶黄苏萍胡堃周科朝孙虹中南大学粉末冶金国家重点实验室长沙410083 中南大学湘雅医院耳鼻喉头颈外科长沙410008

The mesoporous hydroxyapatite （HA） was synthesized by hydrothermal method utilizing cationic surfactant cetyltrimethylammonium bromide （CTAB） as template. The crystalline phase, morphology and porous structure were characterized respectively by different detecting techniques. The results reveal that the particles are highly crystalline hydroxyapatite phase. The surfactant has little influence on the morphology of the crystals, but affects the porous structure obviously. The sample without CTAB has a low surface area not exceeding 33 m^2/g, and no distinct pores can be observed by TEM. While the samples obtained with the surfactant get better parameters. Numerous open-ended pores centered at 2-7 nm spread unequally on the surface of the hydroxyapatite nanorods. The N2 adsorption-desorption experiments show type IV isotherms with distinct hysteresis loops, illustrating the presence of mesoporous structure. When the mole ratio of CTAB to HA is 1：2, the sample has the largest surface area of 97.1 m^2/g and pore volume of 0.466 cm^3/g.

关键词： hydroxyapatite cetyltrimethylammonium bromide cationic surfactant soft-template mesoporous structure

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effects of cationic cetyltrimethylammonium bromide on aggregation behaviors of sodium lignosulfonate in concentrated solutions

Effects of cationic cetyltrimethylammonium bromide on aggreg...

引用

河南省化学会2016年学术年会

作者： Qianqian Tang College of Chemistry and Chemical Engineering and Henan Key Laboratory of Function-Oriented Porous Materials Luoyang Normal University

Effects of cationic cetyltrimethylammonium bromide(CTAB) on aggregation behaviors of sodium lignosulfonate(Na LS) in concentrated solutions were investigated by rheology, conductivity, zeta potential and surface tension measurements. Results showed the presence of CTAB led to increased aggregate effects and enhanced association networks due to intermolecular bridging caused by the formation of mixed aggregates containing Na LS hydrophobes and CTAB molecules at CTAB/Na LS mixing ratios(w/w) below 1:7. However, further additions of CTAB resulted in the progressive disruption of network structures due to electrostatic repulsion between aggregates. The above results also revealed stoichiometric mass ratio(SMR) of Na LS/CTAB system, where the hydrophobicity was strongest and to prepare colloidal spheres was feasible.

关键词： sodium lignosulfonate concentrated solutions cetyltrimethylammonium bromide aggregation rheology

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Preparation of Mesoporous Nano-Hydroxyapatite Using a Surfactant Template Method for Protein Delivery

引用

Journal of Bionic Engineering 2012年第2期9卷 224-233页

作者： Xiaodong Wu Xiaofeng Song Dongsong Li Jianguo Liu Peibiao Zhang Xuesi Chen Department of Bone and Joint Surgery First Hospital of Jilin UniversityChangchun 130021P R.China Key Laboratory of Polymer Ecobiomaterials Changchun Institute of Applied ChemistryChinese Academy of SciencesChangehun 130022P.R.China

Mesoporous nano-hydroxyapatite （n-HA） has gained more and more attention as drug storage and release hosts. The aim of this study is to observe the effect of the ratio of surfactant to the theoretical yield of HA on the mesoporous n-HA, then to reveal the effect of the mesoporous nanostructure on protein delivery. The mesoporous n-HA was synthesized using the wet precipitation in the presence of cetyltrimethylammonium bromide （CTAB） at ambient temperature and normal atmospheric pressure. The morphology, size, crystalline phase, chemical composition and textural characteristics of the product were well characterized by X-ray Powder Diffraction （XRD）, Fourier Transform Infrared Spectroscopy （FTIR）, Scanning Electron Microscopy （SEM）, Transmission Electron Microscopy （TEM）, Dynamic Light Scattering （DLS） and N2 adsorption/desorption, respectively. The protein adsorption/release studies were also carried out by using Bovine Serum Albumin （BSA） as a model protein. The results reveal that the mesoporous n-HA synthesized with CTAB exhibits high pure phase, low crystallinity and the typical characteristics of the mesostructure. The BSA loading increases with the specific surface area and the pore volume of n-HA, and the release rates of BSA are different due to their different pore sizes and pore structures, n-HA synthesized with 0.5% CTAB has the highest BSA loading and the slowest release rate because of its highest surface area and smaller pore size. These mesoporous n-HA materials demonstrate a potential application in the field of protein delivery due to their bioactive, biocompatible and mesoporous properties.

关键词： hydroxyapatite nanoparticles mesostructure cetyltrimethylammonium bromide drug delivery

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Interaction in Binary Mixtures of Gemini Surfactant G12-6-12 and CTAB by NMR

引用

Chinese Journal of Chemical Physics 2014年第3期27卷 307-314页

作者： Jin-zhi Zhang Li Xie Shi-gan Chai Qi-chao Zou Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials College of Chemistryand Chemical Engineering Ministry-of-Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules Hubei University Wuhan 430052 China

The interaction between N, N′-bis（dimethyldodecyl）-1,6-hexanediammoniumdibromide （G12-6-12） and cetyltrimethylammonium bromide （CTAB） in D20 aqueous medium has been investigated by NMR at 298 K. The G12-6-12 and CTAB are about 0.773 and measured critical micelle concentration （cmc） of 0.668 mmol/L, respectively. The cmc^＊（cmc of mixture） values are less than CMC^＊（cmc of ideally mixed solution） in the mixed system, and the interaction parameter βM〈0 at different molar fractions α of G12-6-12 in the mixed systems, but just when α≤0.3, cmc^＊ values are much smaller than CMC^＊, and βM satisfies the relation of ｜βM｜〉｜ln（cmc1/cmc2）｜（cmcl： cmc of pure G12-6-12 and cmc2： cmc Of pure CTAB）. The results indicate that there exists synergism between G12-6-12 and CTAB, and they can form mixed micelles, which is further proven by 2D NOESY and self-diffusion coefficient D experiments. There are intermolecular cross peaks between G12-6-12 and CTAB in 2D NOESY, and the radius of micelles in mixed solution is bigger than that in G12-6-12 pure solution in D experiments, indicating there are mixed micelles. However, when α〉0.3, we find that cmc^＊≈CMC^＊, βM≈0, obviously, the two surfactants are almost ideal mixing fitting the pseudo-phase separation model and regular solution theory.

关键词： Interaction Gemini surfactant cetyltrimethylammonium bromide NMR

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Electrodeposition of Ni-Co-Fe_2O_3 composite coatings

引用

Journal of Central South University 2010年第4期17卷 708-714页

作者：马莉周科朝李志友魏秋平 Key State Laboratory of Powder Metallurgy Central South University School of Materials Science and Engineering Central South University

Ni-Co-Fe2O3 composite coatings were electrodeposited using cetyltrimethylammonium bromide(CTAB)-modified Watt's nickel bath with Fe2O3 particles dispersed in *** effects of the plating parameters on the chemical composition,structural and morphological characteristics of the electrodeposited Ni-Co-Fe2O3 composite coatings were investigated by energy dispersive X-ray(EDS) spectroscopy,X-ray diffractometry(XRD) and scanning electron microscopy(SEM).The results reveal that Fe2O3 particles can be codeposited in the Ni-Co *** codeposition of Fe2O3 particles with Ni-Co is favoured at high Fe2O3 particle concentration and medium stirring,and the deposition of Co is favoured at high concentration of ***,the study of the textural perfection of the deposits reveals that the presence of particles leads to the worsening of the quality of the observed preferred *** with high concentration of embedded particles exhibit a preferred crystal orientation of .The more the embedded Fe2O3 particles in the metallic matrix,the smaller the sizes of the crystallite for the composite deposits.

关键词： electrodeposition Co-Ni alloy Fe2O3 particles composite coatings cetyltrimethylammonium bromide

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Sensitive determination of DNA based on resonance light scattering enhancement of azocarmine G and CTAB

引用

Journal of Central South University of Technology 2005年第6期12卷 688-692页

作者：陈展光任凤莲司士辉廖栩泓丁卫锋刘锦斌 School of Chemistry and Chemical Engineering Central South University Changsha 410083 China Department of Chemistry Shantou University Shantou 515063 China

A new method for the determination of DNA was developed with azocarmine G(AG) in the presence of cetyltrimethylammonium bromide(CTAB) by the resonance light scattering (RLS) technique. The synthetic samples were determined with satisfactory results, and the reaction mechanism was also studied. The results show that underthe optimum conditions, the weak RLS signal of AG can be enhanced by DNA, which results from the formation of a new ternary complex AG-CTAB-DNA with large size. Moreover, the enhanced RLS intensity at 552 nm is directlyproportional to the concentration of DNA in the range of 01.0 μg/mL for fish sperm DNA (fsDNA) and 01.5 μg/mLfor calf thymus DNA (ctDNA). Based on this, a new assay of DNA can be established. The detection limits (3σ) are 2.1 ng/mL for fsDNA and 2.2 ng/mL for ctDNA, respectively.

关键词： determination resonance light scattering azocarmine G DNA cetyltrimethylammonium bromide

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：