We report on the kinetics of crystallization of polyoxacyclobutane (POCB) and water to form a cocrystal hydrate, the first paper to explore the kinetics of crystallization of a polymer with a small molecule. POCB has unusual cocrystallization behavior when mixed with water, which could be exploited for a variety of applications including improving the nonvolatile memory storage capabilities of carbon nanotube devices, water purification, and biomedical applications such as drug delivery. The rates of hydrate crystallization of a series of mixtures containing up to 24 wt % water were measured using both a bulk, volumetric and a localized, spherulite growth approach. At these compositions, all mixtures were single-phase homogeneous liquids prior to hydrate crystallization, and all mixtures were POCB-rich as compared to the cocrystal stoichiometry. The time dependence of crystallization kinetics is well described by the Avrami equation. Reducing temperature, i.e., increasing undercooling, increases the Avrami exponents and increases spherulite growth velocities consistent with the Hoffmann–Lauritzen model. Reducing water content reduces spherulite growth velocities. The velocities also reduce with time during spherulite growth reminiscent of impurity effects in crystallization. Talc was found to accelerate nucleation. Broadly, the cocrystallization process starting from the homogeneous mixtures of the components resembles homopolymer crystallization, but with the complexity that when the mixture composition deviates from the cocrystal stoichiometry, the excess species cannot crystallize fully.

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We quantified the impact of support interactions on the binding and interaction energies of CO and O adsorbed on Pt 13 nanoclusters supported on amorphous silica surfaces through the use of density functional theory calculations. We used an accurate model for amorphous silica having two different surface silanol concentrations, corresponding to low (200 °C) and high (715 °C) surface pretreatment temperatures. We compared CO and O adsorbed on supported and freestanding Pt 13 clusters. We found that Pt 13 is highly susceptible to both support-and adsorbate-induced reconstruction, depending on the relaxed structure of the Pt 13 cluster on the surface. Structure relaxation effects dominate over electronic effects of the support. We considered an ensemble of 50 different systems by varying the placement of the Pt 13 cluster on the surfaces and by exploring a range of different binding sites for CO and O on the Pt 13 cluster. In select cases, binding energy differences between supported and freestanding Pt 13 are as large as 2 eV. However, the mean absolute error between supported and freestanding clusters over all systems we studied is only a few tenths of an eV. Coverage effects on coadsorption of CO and O are significantly different on supported clusters compared with the Pt(111) surface. Our results can be used for predicting when support interactions may be important for any reaction catalyzed by small metal nanoclusters.