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093_Wool keratin based nanofibers - A.Aluigi

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093_Wool keratin based nanofibers - A.Aluigi Powered By Docstoc
					                INSTITUTE FOR MACROMOLECULAR STUDIES




     WOOL KERATIN-BASED
    NANOFIBRES FOR ACTIVE
 FILTRATION OF AIR AND WATER
  A. Aluigi, C.Vineis, A. Varesano, C. Tonetti, C. Tonin, G.Mazzuchetti.




2nd International Conference on Innovative Natural Fibre Composites for Industrial Applications
                                   Rome, April 15-18, 2009
Wool                                             Feather




                       KERATINS
               High Cysteine Content Protein
               (7-20% of the total aminoacids)


                                                 Hair
Horns, Nails
    > 5.000.000 tons/year of keratin wastes from

   By-products of the textile industry
   Poor quality raw wool not fit for spinning
   Hairs and feathers from butchery




     KERATIN WASTES: Renewable Source
                            Intermidiate Filaments
                             Low-Sulphur Content
   Wool Fibre                  Keratin (1,5 -2 %wt)
                               (LS)
                             MW: 60, 45 kDa
                             a-Helix Structure




                         Cuticle
Matrix                    High-Sulphur Content
 High-Sulphur Content     Keratin (8%wt) (HS)
  Keratin (8% wt) (HS)    MW: 28-11 kDa
 MW: 28-11 kDa           b Sheet-Disordered
 Disordered Structure     Structures
                                              AIM
            Keratin from Wool                                  Nanofibre Non-Wovens


  Properties of regenerated wool keratin                       Nanofibre non-wovens properties
 Heavy metals absorption [1]                                     High surface/volume ratio
 Formaldeyde absorption [2]                                           High porosity




                                           Filtration System
                                            Air Cleaning
                            Water depuration: especially removal of
                             ultrafine particles and heavy metals
                                          adsorption




[1] P. Kar and M. Misra, J. Chem. Technol Biotechnol, 2004, 79, 1313-1319
[2] X. Huang, Y. J. Wang and Y. H. Di, Textile Research Journal, 2007, 77(12), 946-950
   Nanofibre Production by Electrospinning
                                             Electrostatic forces


                                         Elongational forces able to
                                           transform the polymer
                                           solution in nanofibres


Basic setup for an electrospinning apparatus
High voltage supplier                  [10  30 KV DC]
Syringe with a small diameter needle   [0.2  1.5 mm]
Metal collecting screen
  Keratin
                                                   metabisulphite [0.6M];
Extraction                               +              Urea [8M];
from Wool                                           SDS [0.02M]; pH 6.5
                                                     Shaking, 65°C, 2h
                                                            Filtration




  Solid Fraction                                                         Liquid Fraction
                                                                                        Dialysis
                                                                                        Filtration
                                                                                         5 m
                   LS                        Casting 50°C
                                              overnight
                   Regenerated Keratin                                    Keratin/H2O
                          Film




                   HS
Regenerated Keratin Characteristic

Poor mechanical properties             Polymer Blend

                                      Common solvent use
   Non-Thermoplastic                      (volatile)


                              PA 6
      Keratin                20 kDa




                                         Used to produce filters
        Keratin/Formic Acid Solution Stability
                                             Keratin / Formic Acid
   Extracted Keratin
    in Formic Acid
         5% wt


                Casting 50°C
                overnight

                               SDS-PAGE
        Films of
Keratin regenerated from
      Formic Acid




                                          1 Standard
                                          Keratin regenerated from formic acid:
                                          2 2 days
                                          3 After two weeks
                                          4 After 1 month
                                          5 After 3 months
                                 Film




Regenerated Keratin
  in Formic Acid      Blends
      15% wt           0/100
                       10/90
                       30/70
        +              50/50
                       70/30    Nanofibre
    Polyamide 6        90/10   Non-Woven
  in Formic Acid       100/0
      15% wt
                            Solution Properties
  Blend solution
decanted overnight              Cryogenically fractured sections of blend films




                Viscosity
                                                            Additivity Rule
                                                           ln T     w ln
                                                                      i
                                                                           i     i


                                                   wi  weight fraction of the i th component
                                                   T  theoretical vis cos ity
                                                    i  solution viscosity of i th component



                                                     Immiscibility between
                                                    keratin and polyamide 6
              Electrospinning Conditions


Voltage (kV): 15 20 25 30

Flow Rate (ml/min): 0,001 0,005 0,01

Tip-to-Target Distance (cm): 10

Capillary (mm): 0,40
Nanofibre Morfology




                      Beads
Diameter Size Distributions of Blend Nanofibres
   Water Stability




1 day immersion in water
                Preliminary test of chromium adsorption
                        Stock Solution




                         [Cr+3]0=50 g/L
                              pH=4


             Adsorbing Capacity q(g/mg)

                                q0  q1
                   q(μg/mg) 
                                  m

q0  Cr 3 amount in the stock solution before adsorption
q1  Cr 3 amount in the stock solution after adsorption, 2 h
Formaldehyde Adsorption
          Formaldehyde Adosrption Apparatus
 FormaldemeterTM                       Formaldehyde
                                       releasing silica




Multicomponent filter
 made of nanofibres                        Chamber
 deposited in a PP                    containing 0.6 ppm
     filter sheet                      of formaldehyde
                                                                 Physiosorption


                                                             Physiosorption
                                                                   +
                                                             Chemisorption




Decrease of formaldehyde concentration with an initial concentration of 0.6
              ppm (100%) during time in the presence of filters
                    Tests performed at 20°C and 65% r.h.
                           CONCLUSIONS

 Keratin/Polyamide 6 blend solutions in different proportions were
 prepared using formic acid as a common solvent
 Morphological analysis and viscosity measurements suggest immiscibility
 between the two polymers
 All the blend solutions were suitable for electrospinning and thin
 nanofibres with diameter ranging from 70 to 300 nm were obtained
 The stability in water of keratin/polyamide 6 blend nanofibres decreases
 with increasing the keratin content
Keratin based nanofibres show a good chromium adsorption capacity
 Keratin based nanofibres are good formaldehyde absorbers, reducing
 airborne formaldehyde concentration up to 70%
…REGIONE PIEMONTE (HI-TEX Project) and
CASSA DI RISPARMIO DI BIELLA Foundation for
the financial support


… ALL of YOU for your attention!!

				
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