Formation of Tethered Nanolayers:  Three Regimes of Kinetics

Abstract

An investigation of the kinetics of tethering of amine functional-ended polystyrene from good solvent to the surface of a solid substrate showed three distinct regimes of kinetics rather than the two predicted by theory. The first regime was fast and appeared to be controlled by diffusion through the solvent, as predicted by theory. The second regime was slow and appeared to be linear in the natural logarithm of time, as predicted by theory. The third regime, not predicted by theory, was one of accelerated tethering (termed by us "layer-assisted tethering"). The third regime, observed for different solvents, different molecular weights, and different temperatures, ended when saturation was reached. We suggest herein an explanation for the observed acceleration.

Single-Molecule AFM Study of Polystyrene Grafted at Gold Surfaces

“…Polymer-rupture forces using different AFM tip materials, Si and Au, in the same medium, H 2 O, indicate higher interfacial tensions between the Au AFM tip and the polystyrene surface. The grafting densities were estimated using ellipsometry and found to be 0.005 chains=nm 2 for 0.6-nm-thick film, which is close to a recently reported [31] value for the mushroom conformation of 15 K polystyrene (0.009 chains=nm 2 ).…”

RETRACTED ARTICLE: A focus on the features of polyaniline nanofibres prepared via developing the single crystals of their block copolymers with poly(ethylene glycol)

“…However, the crystallization of well-defined, uniform and high-quality single crystals can be achieved in the supercooled dilute solutions, and mostly by the self-seeding method [51][52][53][54][55][56][57]. Among various methods for developing the polymer brushes (tethered chains on a substrate) comprising grafting to [58][59][60][61][62], grafting from [63][64][65], and single crystal growth of block copolymers [52,56,[66][67][68], the latter approach can accurately control and tune the uniform distribution of tethered brushes [51,52,56,66,[69][70][71][72][73][74]. So far, there is a limited literature on the polymer semiconductor single crystals or highly crystalline self-assembled nanostructures, for example, poly(3-hexylthiophene) (P3HT) [75], poly(3butylthiophene)-b-polyethylene (P3BT-b-PE) [76] and PANI-b-PEG-b-PANI [46].…”

Hairy nanoparticle assemblies as one-component functional polymer nanocomposites: opportunities and challenges

“…This limitation slows the grafting kinetics to logarithmic time once the graft density is high enough for the corona near the particle surface to enter the concentrated brush regime. [96] In addition, the number of chains per particle is not constant in a typical synthesis procedure-Oyerokun and Vaia [97] showed that the chain distribution is Gaussian and becomes wider as the polymer increases in size relative to the particle. Another limitation is the synthesis of the polymer with the appropriate terminal group-for example, alkoxysilanes and chlorosilanes are reactive, and may not be compatible with the polymerization techniques preferred or the backbone of the polymer.…”