Scattering properties of dipolar gels

作者：Tong Chaohui^*; Vilgis Thomas A

来源：Macromolecules, 2008, 41(16): 6210-6216.

DOI：10.1021/ma800438h

We study the effects of dipolar interactions of polymer chains where the dipolar moments are aligned along the polymer segments on the scattering proper-ties of dipolar gels made by randomly cross-linking dipolar chains in polar solvent. Using the field-theoretical approach, the dipolar interactions of polar solvent and dipolar polymer segments are decomposed into Cartesian components which enables the use of collective density variables. After integrating out the degree of freedoms due to dipolar interactions of polymer segments, it is found the effective interactions between monomer density fields are increased, and the net increase in the effective interactions due to dipolar interactions of polymer segments increases with wavenumber and the magnitude of dipolar moment of polymer segments. Because of the increase of effective virial coefficients of dipolar gels, both the thermal fluctuations and static density inhomogeneities of such gels are suppressed compared to its neutral counterparts. Similar to uniaxially stretched neutral gels, the scattering intensity is enhanced in the direction along the stretching axis for dipolar gels. Also in the direction parallel to the stretching direction, it is found there is enhanced orientational ordering of dipolar density field in Theta solvent.

• 出版日期2008-8-26