Bruce L. Carvalho

We have studied the kinetics of spinodal decomposition in a gelatin-water-methanol mixture, which undergoes a sol-gel transition simultaneously with phase separation, using light scattering techniques. The kinetics of the sol-gel transition was investigated using falling-ball microviscometry techniques. We found that the kinetics of phase separation depend very strongly on temperature; and for deep quenches, where the rates of phase separation and gelation are comparable, the phase-separation process does not go to completion. Prior to the onset of gelation the initial growth rate of the structure factor can be described according to the Cahn-Hilliard model, even though the wavevector at maximum scattered intensity decreases as km ∼ t−0.6. For deep quenches after the onset of gelation, km remains unchanged with time, while the peak intensity exhibits a slow growth. The final domain size, k−1final, at which the phase-separating morphology becomes pinned decreases with increasing quench depth. Micrographs of the phase-separated domains reveal a connected structure on length scales of a hundred micrometres superimposed on a finer network structure due to gelation.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLowering of the miscibility gap in the dioctanoylphosphatidylcholine-water system by addition of ureaBruce L. Carvalho, Giuseppe Briganti, and Sow Hsin ChenCite this: J. Phys. Chem. 1989, 93, 10, 4282–4286Publication Date (Print):May 1, 1989Publication History Published online1 May 2002Published inissue 1 May 1989https://pubs.acs.org/doi/10.1021/j100347a073https://doi.org/10.1021/j100347a073research-articleACS PublicationsRequest reuse permissionsArticle Views89Altmetric-Citations42LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

Abstract Ordered periodic morphologies are the hallmark of most discussions of the microphase‐separated state in block copolymer systems yet actual materials contain a myriad of defects. Perhaps the most important of these defects are those which constitute the regions between ordered grains. Transmission electron microscopy (TEM) is used to investigate the grain boundary morphology of diblock copolymers in both bulk and thin film geometries. These experiments show that constant mean curvature (CMC) surfaces are often useful descriptors, not only for the equilibrium morphology of microphase‐separated copolymers, but also for the microphase‐separated morphology within grain boundaries.