Le Coeur C, Teixeira J, Busch P, Longeville S
Laboratoire Léon Brillouin, CEA-CNRS, CEA Saclay, 91191 Gif-sur-Yvette, France.
Phys Rev E Stat Nonlin Soft Matter Phys. 2010 Jun;81(6 Pt 1):061914. doi: 10.1103/PhysRevE.81.061914. Epub 2010 Jun 11.
The addition of a macromolecular crowding agent to a dilute solution of polymer exerts a compressive force that tends to reduce the size of the chain. We study here the effect of changing the size ratio between the random coil and the crowding agent. The compression occurs at lower crowding agent concentration, Φ when polymer molecular weight increases. The Flory exponent ν(Φ) decreases from ν(0)≃0.48 in water down to 0.3 with macromolecular crowding. The effective polymer-polymer interactions change from repulsive to strongly attractive inducing aggregation of the chains. This effect changes drastically for larger polymer sizes, being much more pronounced at high molecular weights.
向聚合物稀溶液中添加大分子拥挤剂会施加一种压缩力，该力倾向于减小链的尺寸。我们在此研究改变无规线团与拥挤剂之间尺寸比的影响。当聚合物分子量增加时，在较低的拥挤剂浓度Φ下就会发生压缩。弗洛里指数ν(Φ)从水中的ν(0)≃0.48下降到存在大分子拥挤时的0.3。有效的聚合物 - 聚合物相互作用从排斥变为强烈吸引，从而诱导链的聚集。对于更大的聚合物尺寸，这种效应会发生巨大变化，在高分子量时更为明显。
