Light‐Scattering Study of the Aggregation of Syndiotactic Poly(methyl methacrylate) in Solution

Abstract

Syndiotactic poly(methyl methacrylate (s-PMMA) may undergo aggregation in n-butyl chloride (n-BuCl) at temperatures below the theta temperature. The aggregation behavior of the s-PMMA with weight-average molecular weight M(w) =6.06 x 10(5) g mol(-1) was studied by a combination of static and dynamic laser-light-scattering experiments. A solution of concentration 1.12 x 10(-4) g mL(-1) was quenched from 50 degrees C (above the theta temperature in n-BuCl, 35 degrees C to 12 degrees C, and the aggregation process was measured over 60 h. The time dependence of M(w) the root-mean-square z-average radius of gyration < R(g) >, and the average hydrodynamic radius <R(h)> were used to monitor the growth of the aggregates, with the result M(w) approximately < R(g) > d(f) (where d(f) = 1.98 +/- 0.02), which implies the formation of a fractal aggregate. The observed fractal dimension, d(f), is close to that expected for a reaction-limited cluster aggregation for which d(f) = 2.1. In addition, atomic force microscopy was used to image the aggregates.

Menger sponge-like fractal body created by a novel template method

“…[28][29][30][31][32] Since the densities ͑2.4 g cm −3 ͒ of the silica prepared by same process without AKD particles were same to that of usual glass, the prepared samples correspond to SiO 2 glasses with pores. First, we would like to point out that our strategy was based on the template method and the sol-gel process of bulk SiO 2 .…”

“…22 The authors investigated the possibility of the localization in the cavities at different generations, and found that it was realized in the cavity at the third generation, where "the n -th generation" means the number of hierarchical structure developed or the pore size distribution in a Menger sponge. [28][29][30][31][32][33] In this article, we will present the first experimental report on the creation of Menger sponge-like fractal body and the design of its fractality with a novel template method. 27 The essence was that the fractal surface structures enhanced the dewetta-bility.…”

Large-Scale Supramolecular Structure in Solutions of Low Molar Mass Compounds and Mixtures of Liquids. III. Correlation with Molecular Properties and Interactions

“…Static and dynamic laser light scattering used as the main techniques in this work proved to be exceptionally powerful in the studies of various kinds of aggregation and association phenomena, especially in macromolecular systems. − The suitability of these techniques for the study of association phenomena comes from the fact that intensity of scattered light as well as its other static and dynamic characteristics change very strongly upon association.…”

The Structure and Aggregation of Hydrogen‐Bonded Interpolymer Complexes of Poly(acrylic acid) With Poly(N‐vinylpyrrolidone) in Dilute Aqueous Solution

“…This can explain values of R g / R h ratio above 1, which are characteristic for loose particles. [ 48 ] The composition dependence of the shape parameter is also clearly seen in Figure 9 for PVP-PAA50 system. In x AA range between 0.1 and 0.3, ρ -parameter decreases from 0.8 to 0.6.…”