已为您找到该学者8条结果 成果回收站
【期刊论文】Lamellar phase in colloidal suspensions of positively charged LDHs platelets
孙德军, Ning Wanga, Shangying Liua, Jie Zhanga, Zhonghua Wub, Jun Chenb and Dejun Sun*a
Soft Matter, 2005, 1, 428-430,-0001,():
-1年11月30日
The lamellar phase in colloidal suspensions of positively charged platelets of layered double hydroxides (LDHs) was studied with synchrotron small angle X-ray scattering and optical observations.
-
31浏览
-
0点赞
-
0收藏
-
0分享
-
89下载
-
0
-
引用
【期刊论文】The effect of block copolymer EPE1100 on the colloidal stability of Mg–Al LDH dispersions
孙德军, Xiaoju Wang, Dejun Sun, Shangying Liu *, Rui Wang
Journal of Colloid and Interface Science 289(2005)410-418,-0001,():
-1年11月30日
The adsorption isotherm of block copolymer EPE1100 (polyethylene oxide–polypropylene oxide-polyethylene oxide) on the surfaces of Mg-Al LDH particles was determined through a solution depletion method combined with TOC measurement. X-ray diffraction patterns showed that the adsorption of EPE1100 molecules only occurred on the outer surfaces of LDH particles and they did not intercalate into the galleries between the layers. The adsorption of EPE1100 molecules changed the morphology of the particles. The effect of EPE1100 on the colloidal stability of LDH dispersion was investigated from three aspects: after the freezing-melting cycle, after the shearing rotations, and after the addition of electrolyte. The results indicated that the effect of EPE1100 on the colloidal stability of LDH dispersions was strongly related to the state of copolymer adsorption on LDH particle surfaces. It was inferred that the hydrated repulsive force and steric-repulsive force played important roles in determining the stability of the dispersions.
Layered double hydroxides, Block copolymer, Colloidal stability, Adsorption
-
37浏览
-
0点赞
-
0收藏
-
0分享
-
81下载
-
0
-
引用
孙德军, Limin Zhai, *, †, Mei Zhao, Dejun Sun, ‡, Jingcheng Hao, ‡ and Lungjun Zhang†
J. Phys. Chem. B 2005, 109, 5627-5630,-0001,():
-1年11月30日
Vesicles can be formed spontaneously in aqueous solution of a single anionic surfactant sodium dodecyl benzenesulfonate (SDBS) just under the inducement of salt, which makes the formation of vesicle much easier and simpler. The existence of vesicles was demonstrated by TEM image using the negative-staining method. The mechanism of the formation may be attributed to the compression of salt on the electric bilayer of the surfactant headgroups, which alters the packing parameter of the surfactant. The addition of the zwitterionic surfactant lauryl sulfonate betaine (LSB) makes the vesicles more stable, expands the range of formation and vesicle size, and reduces the polydispersity of the vesicles. The vesicle region was presented in a pseudoternary diagram of SDBS/LSB/brine. The variations of vesicle size with the salinity and mixing ratios, as well as the surfactant concentration, were determined using the dynamic light scattering method. It is found that the vesicle size is independent of the surfactant concentration but subject to the salinity and the mixing ratio of the two surfactants.
-
31浏览
-
0点赞
-
0收藏
-
0分享
-
307下载
-
0
-
引用
【期刊论文】Effect of additives on the cloud points of two tri-block copolymers in aqueous solution
孙德军, Lin Xiuli b, Xu Jian a, ∗, Hou Wanguo a, Sun Dejun a
Colloids and Surfaces A: Physicochem. Eng. Aspects 237(2004)1-6,-0001,():
-1年11月30日
The cloud points (CP) of aqueous solutions of two ethylene oxide–propylene oxide–ethylene oxide tri-block copolymers (EO)10(PO)16(EO)10 and (EO)1(PO)17(EO)1 were measured in the presence of additives, such as salts, alkalis, acids, polymer and ionic surfactant. The results obtained in this study indicated that salts decrease the CP of the two tri-block copolymers in the order of NaCl>CaCl2>MgCl2 and Na3PO4>Na2SO4>NaCl. Alkalis caused a sharp drop of CP of the two tri-block copolymers. Acids increased the CP. Water soluble polymer such as polyvinylpyrrolidone (PVP), hydrolysis polyacrylamide (HPAM) and cation-polyacryamide (cation-PAM) decreased the CP. Ionic surfactants such as sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) increased the CP. The extent of lowering depends on the structure and concentration of additives and the number of ethylene oxide group of tri-block copolymers.
Cloud point, Block copolymers, Ionic surfactant, Polymer
-
39浏览
-
0点赞
-
0收藏
-
0分享
-
507下载
-
0
-
引用
【期刊论文】Synthesis of LDHs and Rheological Properties of Laponite/LDHs Dispersions
孙德军, Pei Zhi GUO, De Jun SUN*, Jie ZHANG
Chinese Chemical Letters Vol. 14, No. 9, pp 973-976, 2003,-0001,():
-1年11月30日
The chemical composition, morphology of the particles of positively charged layered double hydroxides (LDHs) were studied by ICP, Mastersizer, TEM. The preliminary results indicated that with adding LDHs to 1% laponite dispersion the yield stress of laponite/LDHs mixed dispersions increased at first, then decreased dramatically to a minimum, and the yield stress rose again when LDHs increased further.
Laponite,, layered double hydroxide,, rheological properties.,
-
52浏览
-
0点赞
-
0收藏
-
0分享
-
124下载
-
0
-
引用