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SUNMONTUEWEDTHUFRISAT
Events for November 10, 2005
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Lyman Handy Colloquium
Thu, Nov 10, 2005 @ 12:30 AM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Lyman L. Handy Colloquium
Crystal Engineering for Product
& Process DesignProfessor Michael F. Doherty
Department of Chemical Engineering
University of California, Santa BarbaraAbstractCrystalline organic solids are ubiquitous as either final products or as intermediates in the
specialty chemical, pharmaceutical, and home & personal care industries. Virtually all small
molecular weight drugs are isolated as crystalline materials, and over 90% of all pharmaceutical
products are formulated in particulate, generally crystalline form. Crystalline chemical
intermediates, such as adipic acid, are produced in large amounts to make polymers and specialty
products. Skin creams and other personal care product formulations contain crystalline solids. In
most cases the properties of the crystalline solid have a major impact on the functionality of the
product as well as the design and operation of the manufacturing process.
A novel method for modeling the shape evolution of 3-dimensional faceted crystals has been
developed in which the normal distances to each face from an origin inside the crystal are
represented by a system of ordinary differential equations. The model is initialized from an
arbitrary initial seed shape and size, but known polymorph. The growth model for the crystal faces
is based on surface integration kinetics as the rate determining step. The key variables on which
the model depends are (1) properties of the solid state, such as unit cell, space group,
intermolecular potentials, charge distribution, etc, and (2) surface free energy at the crystalsolution
interface. At each time step, the entire family of possible discrete shape evolution events
(e.g., vertices bifurcating into edges or faces, etc.) are exhaustively enumerated and investigated
using a new set of simple testable conditions. The evolving crystal shape is then determined from
the evolving set of normal distances and the corresponding crystallographic planes. The model has
been successfully applied to a selection of complex molecular crystals of interest in pharmaceutical
and specialty chemical products.
In this presentation we discuss the interactions between crystal engineering and
crystallization process & product design. We assess the current status of knowledge in this field and
identify critical areas for future research and development.Thursday, November 10, 2005
Seminar at 12:30 p.m. - OHE 122
Refreshments served after the seminar in HED Lobby
The Scientific Community is Cordially InvitedLocation: Olin Hall of Engineering (OHE) - 122
Audiences: Everyone Is Invited
Contact: Petra Pearce
