# SANS (small-angle neutron scattering) evaluation of the RPA (random phase approximation) theory for binary homopolymer mixtures

## Abstract

A well characterized binary mixture of normal (protonated) and perdeuterated monodisperse 1,2 polybutenes has been studied by small-angle neutron scattering (SANS). For scattering wavevectors q greater than the inverse radius-of-gyration R/sub g//sup -1/, the SANS intensity is quantitatively predicted by the random phase approximation (RPA) theory of deGennes over all measured values of the segment-segment interaction parameter Chi. In the region (Chi s-Chi)Chi s/sup -1/ > 0.5 the interaction parameter determined using the RPA theory for q > R/sub g//sup -1/ is greater than that calculated from the zero-angle intensity based on an Ornstein-Zernike plot, where Chi s represents the limit of single phase stability. These findings indicate a correlation between the critical fluctuation length xi and R/sub g/ which is not accounted for by the RPA theory.

- Authors:

- Publication Date:

- Research Org.:
- Oak Ridge National Lab., TN (USA); Bell Labs., Murray Hill, NJ (USA); Exxon Research and Engineering Co., Annandale, NJ (USA). Corporate Research Science Lab.

- OSTI Identifier:
- 6653457

- Report Number(s):
- CONF-861274-1

ON: DE87004253

- DOE Contract Number:
- AC05-84OR21400

- Resource Type:
- Conference

- Resource Relation:
- Conference: Symposium on scattering from block copolymers and model systems, Boston, MA, USA, 1 Dec 1986; Other Information: Paper copy only, copy does not permit microfiche production

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS SCIENCE; POLYMERS; STRUCTURE FACTORS; DEUTERATION; NEUTRONS; SMALL ANGLE SCATTERING; BARYONS; CHEMICAL REACTIONS; ELEMENTARY PARTICLES; FERMIONS; HADRONS; NUCLEONS; SCATTERING; 656002* - Condensed Matter Physics- General Techniques in Condensed Matter- (1987-); 360601 - Other Materials- Preparation & Manufacture

### Citation Formats

```
Bates, F S, Koehler, W C, Wignall, G D, and Fetters, L J.
```*SANS (small-angle neutron scattering) evaluation of the RPA (random phase approximation) theory for binary homopolymer mixtures*. United States: N. p., 1986.
Web.

```
Bates, F S, Koehler, W C, Wignall, G D, & Fetters, L J.
```*SANS (small-angle neutron scattering) evaluation of the RPA (random phase approximation) theory for binary homopolymer mixtures*. United States.

```
Bates, F S, Koehler, W C, Wignall, G D, and Fetters, L J. Mon .
"SANS (small-angle neutron scattering) evaluation of the RPA (random phase approximation) theory for binary homopolymer mixtures". United States. https://www.osti.gov/servlets/purl/6653457.
```

```
@article{osti_6653457,
```

title = {SANS (small-angle neutron scattering) evaluation of the RPA (random phase approximation) theory for binary homopolymer mixtures},

author = {Bates, F S and Koehler, W C and Wignall, G D and Fetters, L J},

abstractNote = {A well characterized binary mixture of normal (protonated) and perdeuterated monodisperse 1,2 polybutenes has been studied by small-angle neutron scattering (SANS). For scattering wavevectors q greater than the inverse radius-of-gyration R/sub g//sup -1/, the SANS intensity is quantitatively predicted by the random phase approximation (RPA) theory of deGennes over all measured values of the segment-segment interaction parameter Chi. In the region (Chi s-Chi)Chi s/sup -1/ > 0.5 the interaction parameter determined using the RPA theory for q > R/sub g//sup -1/ is greater than that calculated from the zero-angle intensity based on an Ornstein-Zernike plot, where Chi s represents the limit of single phase stability. These findings indicate a correlation between the critical fluctuation length xi and R/sub g/ which is not accounted for by the RPA theory.},

doi = {},

journal = {},

number = ,

volume = ,

place = {United States},

year = {1986},

month = {12}

}