Carson Meredith Georgia Tech ChBE/IPST

Transcription

1 Ph. D. Research in the Meredith Group Fall 2011 Bio-Inspired Sensors and Advanced Materials from Renewable Resources Carson Meredith Georgia Tech ChBE/IPST

2 Outline Three project areas relevant to new bio-based materials Optical materials / whitening materials (Jie Wu) Lightweight composites for transportation Bio-inspired adhesive particles Bio-enabled sensor particles 2 LM-AFRL X-55

3 BioPAINTS : Bio-enabled Particle Adherents for INTegrative Spectroscopy 3

4 Scientific Motivation Address existing knowledge and capability gap for design, synthesis, and characterization of particles that combine Dispersion on demand Tailored adhesion to surfaces Tailored optical excitation and emission Remote and covert overt optical detection F Polymer film 4

5 Biological Models: Adhesion & Optics Pollen Diatoms Marine luminescent species 5

6 Technological Motivation Basic processes to support potential military / security applications Remote tracking of movement / position Covert search and rescue Intelligence and security Dual use applications (commercial) Adhesives Medicine (diagnostics / imaging / drug delivery) Security inks and watermarks Inventory management Agrochemical delivery 6

7 Program Overview $7.5 Million funding from Air Force 5 years PI (Meredith) + 8 Co-Pis 8 PhD students and 8 post docs Georgia Tech Technical University of Dresden (Germany) University of Arizona Scripps Institution of Oceanography South Dakota State University 7

8 People - Expertise Biology Adhesion Fabrication Nicole Poulsen GT Mark Hildebrand SIO Carson Meredith GT Cheng Zhang SDSU Ken Sandhage GT Nils Kroger GT Dimitri Deheyn SIO Optics Bob Norwood UA Joe Perry GT 8

9 Project Structurerated Approach Thrust 1: Bioparticle Adhesion (CM) 1.1 High-throughput screening (CM,MH) 1.2 Detailed Adhesion (CM) 1.3 Biomolecular Control (NK,NP,MH) Structures Bio-templates Assess Adhesion processes Thrust 2: Adhesive Particle Synthesis (JP) 2.1 Lithographic Particle Fabrication (JP,RN) 2.2 Chemical Particle Tailoring (KS) 2.3 Bioinspired Synthetic Adhesives (CZ) Particles Structures 9 Evaluate effects on adhesion Thrust 3: Spectroscopic Interrogation (RN) 3.1 Chemical-Tailored Optical Resonators (KS, NK) 3.2 Organic chromophore development (CZ) 3.3 Biochromophore characterization (DD)

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11 Lightweight composites for transportation Airlines: Composite Materials Lower Operating Costs Increased fuel economy with lighter weight Reduced time for maintenance and minor repairs 11 LM-AFRL X-55

12 Large potential market that can absorb high materials costs Boeing 787 case study for airframe materials 1.Short Term - Performance filler 1. low loadings added to existing materials tons per year at 3 wt.% Boeing Aero Magazine 12 II. Long Term Replacement of carbon fiber 1. CNCs spun into fiber tons per year

13 Estimated cellulose nanocrystal Like carbon fiber, potential for highstrength but light-weight 13

14 Project Goals Overall: Identify fundamental mechanisms of processing and strengthening CNC/NFC-polymer composites relevant to aerospace industry. Commercially-relevant model system -water-borne thermoset polymers -CNCs: single nanocrystals & whiskers (initially) -NFC: nanofibrils (eventually) Specific Aims: 1) Adhesion and reactions at CNC interface with thermoset 2) Humidity effects 3) Thermal Stability & Mechanical Properties 14

15 Model Systems of Study Polyurethane ton per commercial plane Epoxy 12 tons per 787 (35 tons CFRP) Polyimide Higher temperature structural matrix or insulation faa.gov toray.com compositesworld.com Initial phase Ancarez 555 Waterborne Epoxy Resin Anquamine 401 Polyamine (Air Products) 15

16 1) Adhesion: surface reactivity Cellulose surface should participate in reactions with thermoset materials epoxides reactive with protic groups (-OH) isocyanates What is rate relative to bulk curing? Interface segregation of components? Polyamine adsorption water adsorption How does adhesive strength develop with time and water content? What are opportunities for pre-modification of surface of CNC? 16

17 1) Adhesion: Quantitative Atomic Force Microscopy measurement of interfacial adhesion 1. Inorganic particle interactions Lee and Meredith, Langmuir, 2011, 27, Lee and Meredith, Langmuir, 2011, 27, Metal-mineral interactions in the environment Thio, Lee, Meredith, Keller, Langmuir, 2010, 26, Zeolite adhesion to polymers Lee, Bae, and Meredith, Langmuir, 2009, 25, Pollen polyamide / PS adhesion Thio, Lee, Meredith Env Sci Tech, 2009, 43, E. coli polyamide / PS adhesion Thio and Meredith, Col Surf B: Biointerfaces, 2008, 65, Polymers Thio and Meredith, J Coll Int Sci, 2007, 314,

18 2) Humidity Challenge: CNCs are hydrophilic and water can impede curing reactions and hinder component interactions Solution: Understand the impact(s) on composite performance Thermal Analysis: glass transition, curing kinetics, conversion Differential Scanning Calorimetry Conventional and MEMS-based Mechanical Properties: temperatures, rates, loading conditions, environmental humidity Dynamic Mechanical Analysis Quasi-Static Testing 18

19 3) Thermal Stability Challenge: Isolation techniques can further reduce thermal stability of CNCs Adapted from: Roman and Winter, Biomacromolecules (2004) Potential Solutions: 1, 2, and/or 3 1. Isolation Techniques Increasing surface sulfate groups from hydrolysis Bacterial Cellulose 2. Surface Chemistry 3. Curing Strategies Dorgan, Personal Communication (2011) Lu, Askeland and Drzal, Polymer (2008) 19

20 Summary WHY: Significant market potential for forest-based nanocomposites in advanced materials industries Aerospace: 200 to 4000 tons / year CNC of NFC potential size for just one aircraft model Potential for packaging, automotive plastics, adhesives & sensors WHAT: Significant challenges addressed by research USDA FPL-University Collaboration with Georgia Tech Air Force BioPAINTS Multi-University Research Initiative IPST-funded research projects in optical / whitening materials 20

21 Acknowledgements Collaborators Meisha Shofner, Georgia Tech MSE/IPST Greg Schueneman, USDA FPL Yulin Deng, ChBE/IPST access to homogenizer Sven Behrens, ChBE instrument access (Zeta sizer) Students and Postdocs Jie Wu, Natalie Girouard, Timi Fadiran, Ismael Gomez Dr. Shanhong Xu and Dr. Haisheng Lin Funding IPST PSE Fellowship USDA FPL Air Force Office of Sponsored Research 21