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Tirrell
1. Electrostatic Complexes in Polymer Materials Science Feng Li, Phillip Schorr, Akira Ishikubo, Jean-François Argillier, Marc Balastre, Ryan Toomey, Rob Farina, Ray Tu & Matthew Tirrell, with Phil Pincus (UCSB), Jimmy Mays (U Tenn), and Matthias Ballauff (Bayreuth) Chemical Engineering, Materials and BioMolecular Science & Engineering Materials Research Laboratory California NanoSystems Institute Institute for Collaborative Biotechnologies University of California, Santa Barbara [email_address] www.chemengr.ucsb.edu/people/faculty/ tirrell Polymers as Nanomaterials National TsingHua University January 17, 2008
2. Stacking Coordination via multi-valent metals Hydrogen bonding Useful non-covalent interactions for building supermolecular structures Assemblies result from multipicity of weak individual interactions
5. ENCAPSULATION PROCESS BY COMPLEX COACERVATION USING INORGANIC POLYMERS NCR Co. (1970) Document Type and Number: United States Patent 3639256 "Complex coacervation" a process wherein at least two oppositely electrically charged hydrophilic polymeric materials are caused to emerge from aqueous solution by being mutually attracted to and complexed with one another and by, thereby, having their solubility in the aqueous manufacturing vehicle decreased. In the instance of complex coacervation, the emergent phase contains substantially all of the electrically charged hydrophilic polymeric material utilized in forming the complex . Possibilities for supermolecular assembly (Cohen-Stuart, et al
6. Experimental System Charge density >85% N >> M SO 3 - Na + CH 2 [ CH M CH 2 CH [ ] N C 4 H 9 ] Parameters that affect the structure and interaction of polyelectrolyte brushes: adsorption density ( ) a dded salt concentration (Cs) charge density ( ) number of charged segments (N) Large Well-Solvated Block (Hydrophilic) Small Collapsed Block (Hydrophobic) adsorbed onto Hydrophobic surface (Octadecyltriethoxysilane (OTS) onto mica) High affinity with the anchor block
8. Adsorption Mechanisms of Charged, Amphiphilic Diblock Copolymers: The Role of Micellization and Surface Affinity, R. Toomey and M. Tirrell, Macromolecules , 38 , 5137-5143 (2005). Post-Adsorption Rearrangements of Block Copolymer Micelles at the Solid/Liquid Interface, R. Toomey and M. Tirrell, Macromolecules, 39 , 2262-2267 (2006).
9. Experimental System Charge density >85% N >> M SO 3 - Na + CH 2 [ CH M CH 2 CH [ ] N C 4 H 9 ] Parameters that affect the structure and interaction of polyelectrolyte brushes: adsorption density ( ) a dded salt concentration (Cs) charge density ( ) number of charged segments (N) Large Well-Solvated Block (Hydrophilic) Small Collapsed Block (Hydrophobic) adsorbed onto Hydrophobic surface (Octadecyltriethoxysilane (OTS) onto mica) High affinity with the anchor block
10. SFA ( surface force apparatus) SFA Mark II Israelachvili, J. N. Intermolecular and Surface Forces ; Academic Press: San Diego, 1992 Distance ( Å ) F/R Derjaguin approximation: D=2L 0
11. Force Profile Of PtBS 15 /NaPSS 612 (MT 6 ) in Water with Added Salt
12. Force Profile Of PtBS 15 /NaPSS 438 (MT 5 ) in Water with Added Salt
13. Force Profile Of PtBS 27 /NaPSS 747 (MT3) in Water with Added Salt
14. Mono-valent salt concentration dependence of brush height Force curve depending on [NaNO 3 ] [ NaNO 3 ] vs. maximum brush length Osmotic brush regime Salted brush regime Elastic force Osmotic pressure L 0 = brush height L = equilibrium brush height, N = number of monomer units of Kuhn length a, = adsorption density, kT = thermal energy, = ratio of the total number of free mobile counter ions to the total number of monomer segments Pincus, 1991 0.3M 0.12M 0.056M 0.02M 5.6mM 0.92mM 0.11mM Osmotic brush regime salted brush regime
15. Molecular Information and Adsorption Density of PtBS-NaPSS Diblock Copolymers 9.2±0.3 12.5± 0.5 7.4±0.2 Adsorption Density , (10 15 chains/m 2 ) 1.04 1.03 1.04 Polydispersity 84% 85% 87% Degree of Sulfonation , 632 438 747 Chain Length of NaPPS Block, N 15 15 27 Chain Length of PtBS Block MT6 MT5 MT3 Polymer Name
16. Salt Concentration Dependence of the Brush Height Salt concentration dependence of the brush height for the three different brushes. The solid and dash ed lines are linear fits. The dashed lines have slopes close to zero. The slopes for the linear fit 1, 2, and 3 are -0.33 0.02, -0.33 0.02, and -0.30 0.02, respectively.
17. Molecular Weight Dependence of the Brush Height at the Lowest Salt Concentration Molecular weight dependence of the brush height for the four different brushes in the osmotic regime (the lowest salt concentration). is the ratio of the total number of free mobile counterions to the total number of monomer segments .
18. Debye Screening Length and Counterion Condensation Debye screening length -1 = (8 l B c 0 ) -1/2 Gouy-Chapman length = (2 l B c 0 L 0 ) where l B is the Bjerrum length L >> , indicating that the counterions are located inside the brush. The extent of counterion condensation is greater than predicted by Manning theory. 58% 59% 60% Fraction of Counterion Condensation (Manning Theory) 82 5% 84 5% 81 5% Fraction of Counterion Condensation (Experimental) 0.071 0.002 0.091 0.002 0.059 0.002 Concentration of Total Counterions Inside the Brush (M) 0.013 0.002 0.015 0.002 0.011 0.002 Concentration of Free Counterions Inside the Brush (M) 75 5% 79 5% 71 5% Maximum Height of the Brush (in % of the Contour Length) 3 3 2 Gouy-Chapman Length at c 0 (Å ) 27 2 25 2 29 2 Debye Screening Length at c 0 (Å) 0.013 0.002 0.015 0.002 0.011 0.002 Crossover Concentration, c 0 (M) MT6 MT5 MT3 Polymer Name
37. CTAB dilution process CTAB 74mM CTAB 6.4mM CTAB 0.47mM CTAB 0.06mM CTAB 0.01mM L1 L2 * Compressed polymer height decreased * Attractive force increased up to a point
38. Addition of high salt concentration solution NaNO 3 1mM CTAB 0.01mM NaNO 3 0.7M NaNO 3 1.2mM Distance (Å) F/R( N/m) Distance (Å) Distance (Å)
39.
40. Manipulation of Surface Interactions NSF-MRSEC (UCSB-MRL) NSF-NIRT (CTS-0103516) NSF-MWN (DMR-0713827) NIH (HL-R0162427-01, PEN, CCNE) ARO Inst. For Collaborative Biotech. Thank you! Badri Ananthanarayanan Matthew Black Rob Farina Mark Kastantin Brian Lin Rachel Marullo Amanda Trent Hongbo Zeng Former group members (contributing to this work) Akira Ishikubo (Shiseido) Phillip Schorr (Kimberly-Clark) Feng Li (École Normale, Paris) Jean-François Argillier (IFP) Marc Balastre (Rhodia) Ryan Toomey (Univ. of South Florida) STUDENTS: Alejandro Parra Thorsten Neumann Wirasak Smitthapong Dimitris Missirlis Rungsima Chollakup POSTDOCS and VISITORS: