Polymer Nanoparticles: Synthesis and Novel Applications

Sunday May 20, 2007, 8:00 am - 6:00 pm, Santa Clara, California

Technology Focus

Polymer nanoparticles have been produced for decades for use in a variety of high performance materials such as high impact resistant polymers and specialty coatings long before it was fashionable to use the “nano” label.

The extraordinarily large surface area on the nanoparticles presents diverse opportunities to place functional groups on the surface. Particles can be created that can expand/contract with changes in pH, or interact with anti-bodies in special ways to provide rapid ex-vivo medical diagnostic tests. Important extensions have been made in combining inorganic materials with polymers and in combining different classes of polymers together in nanoparticle form.

More recent advances in chemistry, processing techniques, and analytical instrumentation allow a whole host of new types of polymer particles to be made. We now have particles that are hollow, multi-lobed, magnetic, functionalized with reactive groups on the surface, conductive, etc. Our ability to devise new process control strategies have led to the ability to control the shape, chemical composition, internal structure, and morphology of the nanoparticles so as to develop new levels of product performance.

Advanced analytical techniques allow us to measure structure at ever-decreasing length scales. Computer simulations of the events occurring during particle formation have also benefited us in developing control strategies to produce structured particles

Course Objectives

The first part of the course focuses on the wet synthesis methods and chemistries used to produce polymer particles in the 10-1000 nanometer range. Careful attention is paid to the analytical techniques that allow confident measurement of phase-separated structure within these composite particles and the varied applications of such polymer particles. The objectives are to:

• Introduce the diversity of polymer particle sizes, shapes, and chemical composition with structural control at the nano scale
• Describe how particles can be made from either reactive or non-reactive processing techniques, including emulsion polymerization and self assembly

The second part focuses on characterization (analysis and verification) and the wide range of application areas of economic importance. The objectives are to:

• Demonstrate how particles can be characterized by modern instrumental techniques
• Discuss the multitude of applications for polymer nanoparticles
• Provide an interactive learning experience through the use of individual and group exercises and case studies

Course Content

Polymeric nanoparticles are predominantly prepared presently, by wet synthetic routes. Several industrial processes will be described. Emphasis will be placed on the type of polymers and morphology structures that can be synthesized using each process. Controlled radical polymerization will be explored for their ability to provide structural control of polymer chains.

A brief overview of suspension and dispersion-precipitation polymerization relevant to nanoparticles is included. Solution polymerization methods are provided to allow a more detailed presentation of a non-reactive pathway to nanoparticle formation.

The third day is dedicated to polymeric nanoparticles characterization. Of critical importance is the measurement of particle size, bulk and surface chemical composition. Importantly, the internal structure of the particles, can be measured by combinations of microscopy and thermal analysis. All techniques will be presented for their utility toward polymeric nanoparticles characterization.

The fourth day of the course is focused on the applications of polymeric nanoparticles. The most traditional field of application is waterborne paints, adhesives, and coatings. The details of some formulation and application issues will be presented. Of more recent emergence is the field of redispersible lattices, powder coatings, and pressure sensitive adhesives.

A recent boom in the range of application of polymeric nanoparticles is the sector of biotechnology, and more specifically biomedical products. These include the critical delivery of sensitive drugs and medical diagnostics. Last but not least, polymeric nanoparticles have found their ways in EMO devices.

All through the course practical problems will be solved both individually and in groups.

Course Outline

Synthesis

• Polycondensation polymerization
• Radical polymerization
• Living polymerization
• SFRP, ATRP, RAFT for controlled radical polymerization
• Problem solving
• Suspension and dispersion-precipitation polymerization
• Emulsion polymerization
• Semi-batch and batch processes
• Single stage and multistage products.
• Problem solving
• Micro-emulsion and mini-emulsion
• Nanoencapsulation in direct and reverse phases.
• Self-assembly
• Directed assembly
• Patterned substrate effects
• Solvent removal processes
• Problem solving

Characterization

• Size and size distribution.
• CHDF, Capillary Hydro Dynamic Fractionation
• MALS, Multi Angle Light Scattering
• DLS, Dynamic Light Scattering
• Field flow fractionation
• UAC, Analytical Ultra Centrifugation
• SEM, TEM, AFM, microscopy techniques.
• Problem solving
• Bulk chemical composition
• NMR, Nuclear Magnetic Resonance
• Spectroscopic techniques, FTIR, Raman, UV, and fluorescence,
• Problem solving
• Pyrolysis-gas chromatography-mass spectroscopy,
• Mass-spectroscopy
• Surface composition
• Surfactant titration
• XPS, X-ray Photon Spectroscopy
• EDS, Electron Dispersion Spectroscopy
• SERS, Surfaced Enhanced Raman Spectroscopy
• ITC, Isothermal Titration Calorimetry
• Internal structure, TEM, STXM, thermal analysis
• Problem solving

Applications

• Waterborne paints
• Adhesives
• Coatings
• Redispersible latices
• Powder coatings
• Pressure sensitive adhesives
• Hot melts
• Biotechnology
• Biomedical products
• Drug delivery
• Medical diagnostics
• Problem solving
• Electronics
• Magnetics
• Optoelectronics

Course Instructors

Donald C. Sundberg, Ph.D., Director of the Nanostructured Polymers Research Center in the Materials Science Program at the University of New Hampshire, Durham, NH, USA. Professor Sundberg has been working in the field of emulsion polymers for over 37 years. He received a bachelor’s degree in chemical engineering from Worcester Polytechnic Institute in Massachusetts and his Ph.D. from the University of Delaware. He spent 5 years working on impact modifiers for ABS polymers with the Monsanto Company prior to pursuing an academic career. His research interests include polymerization kinetics in solution, bulk and emulsion systems, interfacial science and polymer morphology control, diffusion in polymers, micro- and nano-encapsulation, coatings, and controlled release technology.