Measuring the nematic order of suspensions of colloidal fd virus by x-ray diffraction and optical birefringence -: art. no. 031708

被引:100
作者
Purdy, KR [1 ]
Dogic, Z
Fraden, S
Rühm, A
Lurio, L
Mochrie, SGJ
机构
[1] Brandeis Univ, Dept Phys, Complex Fluids Grp, Waltham, MA 02454 USA
[2] MIT, Ctr Mat Sci & Engn, Cambridge, MA 02139 USA
[3] No Illinois Univ, Dept Phys, De Kalb, IL 60115 USA
[4] Yale Univ, Dept Phys, New Haven, CT 06520 USA
来源
PHYSICAL REVIEW E | 2003年 / 67卷 / 03期
关键词
D O I
10.1103/PhysRevE.67.031708
中图分类号
O35 [流体力学]; O53 [等离子体物理学];
学科分类号
070204 ; 080103 ; 080704 ;
摘要
The orientational distribution function of the nematic phase of suspensions of the semiflexible rodlike virus fd is measured by x-ray diffraction as a function of concentration and ionic strength. X-ray diffraction from a single-domain nematic phase of fd is influenced by interparticle correlations at low angle, while only intraparticle scatter contributes at high angle. Consequently, the angular distribution of the scattered intensity arises from only the single-particle orientational distribution function at high angle but it also includes spatial and orientational correlations at low angle. Experimental measurements of the orientational distribution function from both the interparticle (structure factor) and intraparticle (form factor) scattering were made to test whether the correlations present in interparticle scatter influence the measurement of the single-particle orientational distribution function. It was found that the two types of scatter yield consistent values for the nematic order parameter. It was also found that x-ray diffraction is insensitive to the orientational distribution function's precise form, and the measured angular intensity distribution is described equally well by both Onsager's trial function and a Gaussian. At high ionic strength, the order parameter S of the nematic phase coexisting with the isotropic phase approaches theoretical predictions for long semiflexible rods S = 0.55, but deviations from theory increase with decreasing ionic strength. The concentration dependence of the nematic order parameter also better agrees with theoretical predictions at high ionic strength indicating that electrostatic interactions have a measurable effect on the nematic order parameter. The x-ray order parameters are shown to be proportional to the measured birefringence, and the saturation birefringence of fd is determined enabling a simple, inexpensive way to measure the order parameter. Additionally, the spatial ordering of nematic fd was probed. Measurements of the nematic structure factor revealed a single large peak in contrast to nematics of rigid rods.
引用
收藏
页数:12
相关论文
共 58 条
[11]   ORIENTATIONAL ORDER DETERMINATION IN LIQUID-CRYSTALS BY X-RAY-DIFFRACTION [J].
DEUTSCH, M .
PHYSICAL REVIEW A, 1991, 44 (12) :8264-8270
[12]   Cholesteric phase in virus suspensions [J].
Dogic, Z ;
Fraden, S .
LANGMUIR, 2000, 16 (20) :7820-7824
[13]   Smectic phase in a colloidal suspension of semiflexible virus particles [J].
Dogic, Z ;
Fraden, S .
PHYSICAL REVIEW LETTERS, 1997, 78 (12) :2417-2420
[14]   LIQUID-CRYSTALLINE PROPERTIES OF SOLUTIONS OF PERSISTENT POLYMER-CHAINS [J].
DUPRE, DB ;
YANG, SJ .
JOURNAL OF CHEMICAL PHYSICS, 1991, 94 (11) :7466-7477
[15]   ORDERING IN COLLOIDAL SYSTEMS [J].
FORSYTH, PA ;
MARCELJA, S ;
MITCHELL, DJ ;
NINHAM, BW .
ADVANCES IN COLLOID AND INTERFACE SCIENCE, 1978, 9 (01) :37-60
[16]  
Fraden S, 1995, NATO ADV SCI INST SE, V460, P113
[17]   A VANDERWAALS PICTURE OF THE ISOTROPIC-NEMATIC LIQUID-CRYSTAL PHASE-TRANSITION [J].
GELBART, WM ;
BARBOY, B .
ACCOUNTS OF CHEMICAL RESEARCH, 1980, 13 (08) :290-296
[18]   3-DIMENSIONAL STRUCTURE OF A CLONING VECTOR - X-RAY-DIFFRACTION STUDIES OF FILAMENTOUS BACTERIOPHAGE-M13 AT 7-ANGSTROM RESOLUTION [J].
GLUCKSMAN, MJ ;
BHATTACHARJEE, S ;
MAKOWSKI, L .
JOURNAL OF MOLECULAR BIOLOGY, 1992, 226 (02) :455-470
[19]   NEUTRON-SCATTERING EXPERIMENTS ON MAGNETICALLY ALIGNED LIQUID-CRYSTALLINE DNA FRAGMENT SOLUTIONS [J].
GROOT, LCA ;
KUIL, ME ;
LEYTE, JC ;
VANDERMAAREL, JRC ;
HEENAN, RK ;
KING, SM .
LIQUID CRYSTALS, 1994, 17 (02) :263-276
[20]  
Guinier A., 1994, XRAY DIFFRACTION CRY