Diblock polyampholytes grafted onto spherical particles : effect of stiffness, charge density, and grafting density

Akinchina, A; Linse, P

Abstract

The structure of spherical brushes formed by symmetric diblock polyampholytes end-grafted onto small spherical
particles in aqueous solution is examined within the framework of the so-called primitive model using Monte Carlo
simulations. The properties of the two blocks are identical except for the sign of their charges. Three different chain
flexibilities corresponding to flexible, semiflexible, and stiff blocks are considered at various polyampholyte linear
charge densities and grafting densities. The link between the two blocks is flexible at all conditions, and the grafted
segments are laterally mobile. Radial and lateral spatial distribution functions of different types and single-chain
properties are analyzed. The brush structure strongly depends on the chain flexibility. With flexible chains, a disordered
polyelectrolyte complex is formed at the surface of the particle, the complex becoming more compact at increasing
linear charge density. With stiff blocks, the inner blocks are radially oriented. At low linear charged density, the outer
blocks are orientationally disordered, whereas at increasing electrostatic interaction the two blocks of a polyampholyte
are parallel and close to each other, leading to an ordered structure referred to as a polyampholyte star. As the grafting
density is increased, the brush thickness responds differently for flexible and nonflexible chains, depending on a
different balance between electrostatic interactions and excluded volume effects.

Citation

Akinchina, A., & Linse, P. (2007). Diblock polyampholytes grafted onto spherical particles : effect of stiffness, charge density, and grafting density. Langmuir, 23(3), 1465-1472. https://doi.org/10.1021/la062481r

• Journal Article Type: Article
• Publication Date: Jan 1, 2007
• Deposit Date: Mar 3, 2017
• Journal: Langmuir
• Print ISSN: 0743-7463
• Electronic ISSN: 1520-5827
• Publisher: American Chemical Society
• Volume: 23
• Issue: 3
• Pages: 1465-1472
• DOI: https://doi.org/10.1021/la062481r
• Publisher URL: http://dx.doi.org/10.1021/la062481r
• Related Public URLs: http://pubs.acs.org/journal/langd5/about.html