Biomacormolecular Materials

Transcription

1 Sustainable Bioresource Sciences Biomacormolecular Materials There are close relationships between structures and properties of materials! Contents (1) Rheology property () Scattering (SAXS) structure Daisuke Tatsumi

2 The importance of boundary area especially important for Biomaterials Size from m to nm Research interests from fundamentals (raw materials) to application (industrial products)

3 Utilization of Cellulose Wood fiber assembly Scale Paper fiber re-assembly large Clothes cotton yarn rayon yarnregenerated Foods cocoa microcrystalline Nata de coco gel-like Industrial products Films paints molecular scale small

4 Papermaking c = 1 wt% c = 0 wt% paper c = 9 wt% wire press Wet-end dryer

5 Viscosity of suspensions Cellulose fiber log r 1 Sphere particles r =

6 Pulp fibers

7 Rheological measurements w Wet Pulp Mat C = 5~15 wt% Parallel -plates Rheometer

8 Rheometer Dynamic measurements stress strain strain ( t) exp[ iwt] 0 w * ( t) G 0 exp[ i( t )] ( ) ( w) * G G w ig t 8

9 Frequency dependence log ( G', G" / Pa ) Cellulose fiber web = 0.1% G' G" c / wt% log ( w / s -1 )

10 5 G = kc v 3 log ( G', G'' / Pa ) 4 3 G' G'' PFI mill / rev log ( c v / vol% )

11 LSCM Images mm

12 Microbial Cellulose(BC) pellicle

13 5 log ( G', G" / Pa ) 4 3 G' G" c / wt% log ( w / s -1 )

14 Viscoelastic properties of pellicle log( G', G" / Pa ) w = 0.1 s -1 G = kc 5 slope: 5 G' G" log( c / wt% )

15 Laminated Network Model Fiber D Lattice Model z d l

16 nd d c lz Pc P c lc d Length between Contact Points:

17 Stress transmission z L d l 1 dp dt : transmission efficiency

18 z vd v z L v L v: velocity of momentum When = 1 and /d >> 1, v z vd

19 4 z d l c v d v v G v z = d /lc Here, v = E f / f, l/d p, and f c, E f : Young s modulus of a fiber f : density of a fiber p: axial ratio : density

20 G E For BC pellicle f k p = 1 and /d >> 1 For pulp mat = c*/c c 5 log ( k / Pa ) 4 k p 3 1 slope: log ( p / - )

21 Microcrystalline Cellulose

22 log ( G', G'' / Pa ) Ceolus suspensions G G c (wt%) log ( w / s -1 )

23 log ( G', G" / Pa ) p (approx.) slope: 9/4 log ( c / wt% ) G' G" G = kc.5

24 Summary Pulp Fiber G = kc 3 BC Membrane G = kc 5 MCC G = kc 9/4 a: Network Structure k: Individual Fiber(= Ep )

25 Solution properties of celluloses derived from different origin

26 Cellulose from different origin Crystal structure of natural cellulose Ia Microbial Cellulose Ib Tunicate Cellulose J. Sugiyama, et al., Macromolecules 4, 4168 (1991).

27 Cellulose from different origin Solubility Celluloses 8wt% LiCl/DMAc Soluble Insoluble Tunicin (TC) Dissolving Pulp (DP) Cotton Cellulose (CC) (Isotropic) Microbial Cellulose (BC) (Anisotropic)

28 Liquid crystal from microbial cellulose Polarized microgram plant cellulose 13.6wt% microbial cellulose 13.7wt% 100mm Fiber from liquid crystal

29 Cellulose from Ascidians Halocynthia roretzi High spinnability of TC solution (0.5%)

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31 Wide range Rubbery plateau G ' G" lim w0 w w G" w 1 0

32 log sp o C DP/DMAc DP/DMI CC/DMAc BC/DMAc TC/DMI log c[] Concentration dependence dilute solution sp c 1 semi-dilute soln. sp c 7.5 c 4 c 3 TC DP,CC BC

33 Critical concentration

34 Elementary particle?? R. P. Feynman t B A x

35 Future work for G = kc a Path Integral b i tb K b, a Dxt exp dtl x, x, t a t a b N P mp 1 1 Dxt exp b x x V x a i1 n1 b P i i n n n N Hamiltonian Harmonic Oscillation Percolation (with renormalization)

36 Progress of Science Induction Deduction Principle Results Experiment Explanation Hypothesis Experiment Francis Bacon René Descartes

37 Structural Analysis Microscope directly Light microscope, Electron microscope, Atomic force microscope Fourier Transform Scattering quantitative Light scattering, X-ray scattering, Neutron scattering

38 X-ray diffraction k k dsin n Laue condition a c b a (k k) = h b (k k) = k c (k k) = l

39 X-ray diffraction of cellulose

40 X-ray diffraction of cellulose TC 004 I / a.u. BC d110 d110 a b CC DP d / deg

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42 Small angle X-ray scattering(saxs) small angle SPring-8 q k' k 4 sin

43 SAXS image for pellicle

44 particle size Guinier R q e g 3 particle morphology I q q q (6 D ) D m s Surface Fractal Mass Fractal slope: -4 particle surface specific surface area

45 log (I(q) / a.u.) SAXS image for cellulose liquid crystal 4 3 BC/LiCl DMAc 13.6 wt % Debye-Bueche Exp. DATA L d Correlation length a = 4.5 nm I( q ) K s 1 a q log (q / Å 1 )

46 京都市青少年科学センター蔵

47 REPORT: If you introduce rheology and/or SAXS to your own research, what progress is expected? with your impression