Observations of Self Assembled Bolaform Amphiphiles on Cellulose

1. 2007 International Conference on Nanotechnology for the Forest Products Industry Observations of Self Assembled Bolaform Amphiphiles on Cellulose Sunkyu Park 1, Joseph J. Bozell 1, Josef Oberwinkler 2 June 14, 2007 1 Forest Products Center, University of Tennessee 2 Salzburg University of Applied Sciences, Salzburg, Austria

2. 3 Summary 2 Interaction Between Cellulose and Bolaforms 1 What are Bolaform Amphiphiles? Presentation Contents • Interaction on Cellulose Surface • Interaction with Cellulose Matrix

3. What are Bolaform Amphiphiles?

4. Bolaform Amphiphiles Figure from Fuhrhop and Wang, Chem. Rev. 2004, 104, 2901-2937

5. Bolaforms as Self Assembling Systems Figures from T. Shimizu, Macromol. Rapid Commun. 2002, 23, 311

6. Ferrier Bolaform Synthesis Final product

7. Other Types of Bolaform Amphiphiles

8. Materials Used in this Study Symmetric and C12 Bolaform Amphiphiles Cellulose

9. Cellulose and Bolaform Amphiphiles (1) Interaction on Cellulose Surface

10. xx Materials and Methods • Materials • Cellulose: Microcrystalline cellulose (Avicel) • Pretreatments • MeOH exchange ×3 • DMAc exchange ×3 • Solvent • 8% LiCl in DMAc (N,N-dimethylacetamide) • Solution • Cellulose + Bolaforms + LiCl/DMAc • Methods • A drop on glass-slide • Drying • Polarized optical microscope

11. 200µm Cellulose Film in Absence of Bolaforms Cellulose film without bolaforms in LiCl/N,N-dimethylacetamide

12. 200µm 200µm 50µm 200µm Bolaform Crystallization in Absence of Cellulose Individual structures Bolaforms without cellulose in LiCl/N,N-dimethylacetamide

13. Edge of drop 200µm 200µm Bolaform Crystallization in Presence of Cellulose Bolaforms with cellulose in LiCl/N,N-dimethylacetamide

14. Bolaform Crystallization Process

15. 200µm 200µm 200µm 200µm 200µm 200µm Different Crystal Structures Without cellulose

16. FT-IR Imaging Characterization (1) Image scanning 4000~650 cm-1 Image map at 2918 cm-1

17. FT-IR Imaging Characterization (2) Multivariate analysis of cellulose-bolaforms pellets using statistics package (Unscrambler)

18. FT-IR Imaging Characterization (3) Bolaform concentration mapping

19. MeOH Washing • MeOH washing • All bolaform crystals were immediately dissolved in MeOH

20. Cellulose Film in Absence of Bolaforms Solution: Dissolved cellulose, LiCl/DMAc • Formation mechanism • Evaporation of DMAc • Solidification of dissolved cellulose by H2O Gel-type cellulose pad: Cellulose pad, LiCl/ some DMAc, H2O

21. Cellulose Film in Presence of Bolaforms Solution: Dissolved cellulose, LiCl/DMAc, Dissolved bolaforms • Formation mechanism • Evaporation of DMAc • Solidification of dissolved cellulose by H2O • Individual bolaform crystal formation • Deposition of individual bolaform crystals • (cellulose is acting as nucleating sites) Gel-type cellulose pad: Cellulose pad, LiCl/ some DMAc, H2O, Bolaform crystals

22. Cellulose as a Template for Assembly Kondo et al, PNAS 2002, 99, 14008 Kondo, 2007, Chap. 16 in Cellulose: Molecular and Structural Biology

23. 200µm 200µm 200µm 200µm 200µm 200µm Different Crystal Structures Without cellulose

24. Morphology of bolaform crystals in solvent Template conditions of cellulose gel Air flow Cellulose concentration Bolaforms concentration Relative humidity Temperature… more Control of Bolaform Crystallization • Formation mechanism • Evaporation of DMAc • Solidification of dissolved cellulose by H2O • Individual bolaform crystal formation • Deposition of individual bolaform crystals

25. MeOH Washing 200µm (1) 0 min (2) 0 min, 1st drop (3) 15 min, 2nd drop (4) 30min, 3rd drop (5) 45 min, 4th drop (6) 60 min, 5th drop

26. Bolaform Re-crystallization (7) 75min, 6th drop (8) 90 min, 7th drop (9) After 95 min 90 min, before 7th drop

27. Cellulose and Bolaform Amphiphiles (2) Interaction with Cellulose Matrix

28. Materials and Methods • Materials • Cellulose: Microcrystalline cellulose (Avicel) • Pretreatments • MeOH exchange ×3 • DMAc exchange ×3 • Solvent • 8% LiCl in DMAc (N,N-dimethylacetamide) • Solution • Cellulose + Bolaforms + LiCl/DMAc • Methods • Slow casting in Petri-dish • Washing with H2O • Drying at 60°C (restrained drying) • AFM, SEM, NMR, Sorption test

29. Cellulose-bolaform Film Preparation (1)

30. Cellulose-bolaform Film Preparation (2)

31. FT-IR: Multivariate Analysis Multivariate analysis of bolaform-incorporated cellulose films

32. Film Surface: (1) AFM Images Cellulose in DMAc/LiCl Bolaform/ Cellulose in DMAc/LiCl

33. Film Surface: (2) SEM Images Cellulose Film Cellulose-Bolaform Film

34. Wide Angle X-ray Diffraction X-ray source: CuKα (0.1542nm) 45kV and 0.66mA Beam time: 30min

35. (004) (103) ¯ (110) (110)/(020) Diffraction Patterns for Powders/ Films Avicel Bolaform powder 0% Bolaform Film 5% Bolaform Film 15% Bolaform Film

36. Bolaform powder Cellulose film (bolaforms 15%) Cellulose film (bolaforms 5%) Cellulose film (bolaforms 0%) Avicel powder Amorphous cellulose powder 1D Integrated WAXD Profiles

37. Structural Information for Cellulose Films • Crystallinity index, CI • Crystal size, L k: Scherrer constant, 0.94 λ: x-ray wavelength β: full-width at half-maximum θ: Bragg angle

38. Structural Information: Crystallinity, Crystal Size a) and b) are regression coefficients during the curve fitting procedure

39. Low Resolution NMR • Experimental Parameters • CPMG procedures • τau 0.05 ms • 256 echoes • 750 scans • 5 second recycle delay

40. NMR Relaxation Time

41. Summary

42. Summary • Bolaform amphiphiles were successfully synthesized and the interactions with cellulose were studies. • Highly-ordered self assembly of bolaform amphiphiles were observed on cellulose template, while individual self-assembled structures were found in the absence of cellulose. • Bolaform-incorporated cellulose film showed higher relaxation time, which might be attributed to the interaction between cellulose hydroxyl groups and bolaform molecules.

43. Acknowledgements • Thomas Elder • USDA-Forest Service • Southern Research Station • Pineville, LA • Nicole Labbé • Forest Products Center • The University of Tennessee • John R. Dunlap • Program in Microscopy • The University of Tennessee

44. Thank You!