Evidence from mixed hydrate nucleation for a funnel model of crystallization

• Main Authors: Kyle Wm Hall, Sheelagh Carpendale, Peter G Kusalik
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Antarctic; Antarc*
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.1060.9804; http://chemistry.pnas.org/content/pnas/early/2016/10/05/1610437113.full.pdf

The molecular-level details of crystallization remain unclear for many systems. Previous work has speculated on the phenomenological similarities between molecular crystallization and protein folding. Here we demonstrate that molecular crystallization can involve funnel-shaped potential energy landscapes through a detailed analysis of mixed gas hydrate nucleation, a prototypical multicomponent crystallization process. Through this, we contribute both: (i) a powerful conceptual framework for exploring and rationalizing molecular crystallization, and (ii) an explanation of phenomenological similarities between protein folding and crystallization. Such funnel-shaped potential energy landscapes may be typical of broad classes of molecular ordering processes, and can provide a new perspective for both studying and understanding these processes. nucleation | gas clathrate hydrates | potential energy landscapes | crystallization funnel | molecular dynamics simulation M olecular crystallization and its inhibition are important to a broad range of fields. For example, some organisms [such as Antarctic fish (1) and winter rye (2)] have developed a rich chemistry of antifreeze proteins to control internal freezing, and there is significant interest in exploiting antifreeze proteins for food applications (e.g., see ref. 3). Gas hydrate formation in oil and gas pipelines is a major industrial concern (4). For pharmaceuticals, there is much interest in understanding and controlling crystal polymorphism (e.g., see ref. 5). A better understanding of molecular crystallization, and factors influencing these processes, has potential to aid further advancements in such fields. As highlighted by a recent review on crystallization (6), traditional theoretical models of crystallization (e.g., classical nucleation theory) have proven to be problematic for a variety of systems and there remain technical challenges to studying crystallization both experimentally and computationally, so a clear understanding of crystal nucleation has yet ...