WOOL KERATIN-BASED WOOL KERATIN-BASED NANOFIBRES FOR ACTIVE NANOFIBRES FOR ACTIVE FILTRATION OF AIR AND FILTRATION OF AIR AND

WATERWATERA. 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

INSTITUTE FOR MACROMOLECULAR STUDIES

High Cysteine Content Protein

(7-20% of the total aminoacids)

Wool Feather

Horns, NailsHair

KERATINS

KERATIN WASTES: Renewable SourceKERATIN WASTES: Renewable Source

> 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

Intermidiate Intermidiate FilamentsFilaments

Low-Sulphur Content Keratin (1,5 -2 %wt) (LSLS)

MW: 60, 45 kDa -Helix Structure

CuticleCuticle High-Sulphur

Content Keratin (8%wt) (HSHS)

MW: 28-11 kDa Sheet-Disordered

Structures

MatrixMatrix High-Sulphur

Content Keratin (8% wt) (HSHS)

MW: 28-11 kDa Disordered

Structure

Wool Wool FibreFibre

AIMAIM

Nanofibre Non-Nanofibre Non-WovensWovens

Filtration System

Air Cleaning

Water depuration: especially removal of ultrafine particles and

heavy metals adsorption

Keratin from Keratin from WoolWool

[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

Properties of regenerated wool keratin

Heavy metals absorption [1] Formaldeyde absorption [2]

Nanofibre non-wovens properties

High surface/volume ratio High porosity

Nanofibre Production by Nanofibre Production by ElectrospinningElectrospinning

Basic setup for an electrospinning Basic setup for an electrospinning apparatusapparatus

High voltage supplier [10 30 KV DC]

Syringe with a small diameter needle [0.2 1.5 mm]

Metal collecting screen

Electrostatic forces

Elongational forces able to transform the polymer solution in

nanofibres

Keratin Keratin ExtractioExtraction from n from WoolWool

+metabisulphite

[0.6M]; Urea [8M];

SDS [0.02M]; pH 6.5

Shaking, 65°C, 2h

Filtration

Solid Fraction Liquid Fraction

Keratin/H2O

Casting 50°Covernight

Regenerated Keratin

Film

Dialysis

Filtration5 mLS

HS

KeratinPA 6

20 kDa

Regenerated Keratin Regenerated Keratin CharacteristicCharacteristic

Poor mechanical properties

Non-ThermoplasticCommon solvent

use(volatile)

Polymer Blend

Used to produce filters

Keratin/Formic Acid Solution Keratin/Formic Acid Solution StabilityStability

Keratin / Formic AcidKeratin / Formic Acid

1 StandardKeratin regenerated from formic

acid:2 2 days3 After two weeks4 After 1 month5 After 3 months

Extracted Keratin in Formic Acid

5% wt

Casting 50°Covernight

Films of Keratin regenerated

from Formic Acid

SDS-PAGE

Regenerated Keratinin Formic Acid

15% wt

++

Polyamide 6in Formic Acid

15% wt

BlendsBlends0/1000/10010/9010/9030/7030/7050/5050/5070/3070/3090/1090/10100/0100/0

Castin

g

FilmFilm

Electrospinni

ng

Nanofibre Nanofibre Non-WovenNon-Woven

Blend solution decanted overnight

Cryogenically fractured sections of blend films

Viscosity

Immiscibility between keratin and polyamide 6

i

iiT lnwln

component i ofviscosity solutionitycosvis ltheoretica

component i the of fraction weightw

thi

T

thi

Additivity Rule

Solution PropertiesSolution Properties

Electrospinning ConditionsElectrospinning Conditions

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

Voltage (kV): 15 20 25 30

Tip-to-Target Distance (cm): 10

Capillary (mm): 0,40

Nanofibre MorfologyNanofibre Morfology

BeadsBeads

Diameter Size Distributions of Blend Diameter Size Distributions of Blend NanofibresNanofibres

1 day immersion in water

Water StabilityWater Stability

[Cr+3]0=50 g/LpH=4

Stock Solution

h 2 ,adsorptionafter solution stock in theamount q

adsorption beforesolution stock in theamount

μg/mg)

g/mg)q(Capacity Adsorbing

31

30

10

Cr

Crq

m

qqq(

Preliminary test of chromium Preliminary test of chromium adsorptionadsorption

Formaldehyde Adsorption

Formaldehyde Adosrption Apparatus

Multicomponent filter made of

nanofibres deposited in a PP

filter sheet

Chamber containing 0.6

ppm of formaldehyde

Formaldehyde releasing silica

FormaldemeterTM

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.

Physiosorption

Physiosorption+

Chemisorption

CONCLUSIONSCONCLUSIONS

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%

… ALL of YOU for your attention!!

…REGIONE PIEMONTE (HI-TEX Project) and CASSA DI RISPARMIO DI BIELLA Foundation for the financial support