Crystallization

Chair(s):

• Megan Donaldson, Dow

Schedule

Abstracts

Tailoring the Properties of Zeolites by Exploring Unconventional Routes in Particle Engineering

Jeffrey Rimer, University of Houston

Crystal engineering is a broad area of research that focuses on methods of designing and/or optimizing materials for diverse applications in fields spanning from energy to medicine. The ability to selectively control crystallization to achieve desired material properties requires detailed understandings of the thermodynamic and kinetic factors regulating crystal nucleation and growth. Combining this fundamental knowledge with innovative approaches to tailor crystal size, structure, and morphology can lead to the production of materials with superior properties beyond what is achievable by conventional routes. In this talk I will discuss two general mechanisms of crystal growth: (1) classical pathways involving growth by the addition of monomers (ions or molecules); and (2) nonclassical pathways, termed crystallization by particle attachment (CPA), involving the formation of metastable precursors that play a direct role in crystal nucleation and growth. A ubiquitous approach in crystal engineering to selectively alter the rate(s) of anisotropic growth is through the use of modifiers, which are molecules that interact with specific crystal surfaces and mediate the attachment of growth units. The focus of this talk will be on the rational design of zeolites (nanoporous aluminosilicates) that are heavily used in commercial applications as adsorbents and catalysts. Research efforts that collectively aim to design innovative methods to tailor crystallization and exploit unique structure-performance relationships have the potential to produce materials with superior properties beyond what is achievable by conventional routes. In this talk, I will show how we are using multipronged approaches to tailor material properties, such as particle size, morphology, and composition. Much of our work has focused on elucidating the complex mechanisms of zeolite crystallization, wherein we have developed a unique atomic force microscope (AFM) liquid cell that enables time-resolved imaging of surface growth under solvothermal conditions. I will show how in situ AFM has created new opportunities to probe complex pathways of nonclassical crystallization as part of our broader effort to develop new methods to tailor the physicochemical properties of crystalline materials for commercial applications.