Phase behavior and shear alignment in SWNT-surfactant dispersions

被引：34

作者：

Nativ-Roth, Einat ^{[1
]}

Yerushalmi-Rozen, Rachel ^{[1
,2
]}

Regev, Oren ^{[1
,2
]}

机构：

[1] Ben Gurion Univ Negev, Dept Chem Engn, IL-84105 Beer Sheva, Israel

[2] Ben Gurion Univ Negev, Ilse Katz Inst Nanoscale Sci & Technol, IL-84105 Beer Sheva, Israel

来源：

SMALL | 2008年 / 4卷 / 09期

基金：

以色列科学基金会;

关键词：

carbon nanotubes; cryo-TEM; CTAB; shear alignment; SAXS;

D O I：

10.1002/smll.200800082

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The effect of single-walled carbon nanotubes (SWNT) on the phase behavior of the cationic surfactant cetyltrimethylammonium bromide (CTAB) in aqueous solutions is investigated at room temperature. Small-angle X-ray scattering (SAXS) and cryogenic transmission electron microscopy (cryo-TEM) are used for characterization of bulk dispersions and nanometrically thin films. Additional carbonaceous additives (fullerenes, multi-walled carbon nanotubes, and carbon black) serve as reference systems. It is found that dispersions of carbonaceous additive (excluding fullerenes) at intermediate surfactant concentrations (below the liquid-crystalline region of the native surfactant) induce demixing and macroscopic phase separation in otherwise homogeneous solutions of CTAB. Two coexisting liquid phases of similar CTAB concentrations are observed, with the carbonaceous species residing within the lower phase. At high CTAB concentrations (liquid-crystal region) the SWNTs are found to incorporate into the ordered lyotropic liquid-crystalline phase while preserving the native d-spacing. Investigation of nanometrically thin films at intermediate surfactant concentrations under external shear reveals shear-induced structure (SIS) in the presence of minute amounts of SWNTs. The effect is found to be exclusive to SWNT and does not occur in dispersions of other carbonaceous additives.

引用

页码：1459 / 1467

页数：9

共 37 条

[1] Nanometre-size tubes of carbon [J].

Ajayan, PM ;

Ebbesen, TW .

REPORTS ON PROGRESS IN PHYSICS, 1997, 60 (10) :1025-1062

[2] X-RAY-DIFFRACTION STUDY OF MESOPHASES OF CETYLTRIMETHYLAMMONIUM BROMIDE IN WATER, FORMAMIDE, AND GLYCEROL [J].

AUVRAY, X ;

PETIPAS, C ;

ANTHORE, R ;

RICO, I ;

LATTES, A .

JOURNAL OF PHYSICAL CHEMISTRY, 1989, 93 (21) :7458-7464

[3] Contribution of high-resolution correlative imaging techniques in the study of the liver sieve in three-dimensions [J].

Braet, Filip ;

Wisse, Eddie ;

Bomans, Paul ;

Frederik, Peter ;

Geerts, Willie ;

Koster, Abraham ;

Soon, Lilian ;

Ringer, Simon .

MICROSCOPY RESEARCH AND TECHNIQUE, 2007, 70 (03) :230-242

[4] Biomolecular interactions at phospholipid-decorated surfaces of liquid crystals [J].

Brake, JM ;

Daschner, MK ;

Luk, YY ;

Abbott, NL .

SCIENCE, 2003, 302 (5653) :2094-2097

[5] Structural and dynamical properties of ribbonlike self-assemblies of a fluorinated cationic surfactant [J].

Buhler, E ;

Oelschlaeger, C ;

Waton, G ;

Rawiso, M ;

Schmidt, J ;

Talmon, Y ;

Candau, SJ .

LANGMUIR, 2006, 22 (06) :2534-2542

[6]

CAPPELAERE E, 1995, J PHYS II, V5, P1611, DOI 10.1051/jp2:1995202

[7] LINEAR AND NONLINEAR RHEOLOGICAL BEHAVIOR OF SALT-FREE AQUEOUS CTAB SOLUTIONS [J].

CAPPELAERE, E ;

CRESSELY, R ;

DECRUPPE, JP .

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, 1995, 104 (2-3) :353-374

[8]

Cullity B., 1978, ELEMENTS XRAY DIFFRA

[9] Digital cryogenic transmission electron microscopy: an advanced tool for direct imaging of complex fluids [J].

Danino, D ;

Bernheim-Groswasser, A ;

Talmon, Y .

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, 2001, 183 :113-122

[10] Cryo-TEM of thread-like micelles: on-the-grid microstructural transformations induced during specimen preparation [J].

Danino, D ;

Talmon, Y ;

Zana, R .

COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS, 2000, 169 (1-3) :67-73

← 1 2 3 4 →