Nanocomposites based on cellulose nanofibers: …costfp1205.com/wp-content/uploads/2017/events/Documents/madrid20… · cellulose nanofibers: preparation methodologies and applications

Nanocomposites based on cellulose nanofibers: preparation

methodologies and applications

Carmen S. R. Freire

CICECO

macromolecularlignocellulosic

materialsCICECO-UAveiro

and

macromolecularlignocellulosic

materialsCICECO-UAveiro

and

CENTRE FOR RESEARCH IN CERAMICS AND COMPOSITE MATERIALS CICECO main lines of expertise are: - Nano- and Micro-Structured Materials for Information and Communication Technology - Materials for Energy and Industrial Applications

- Sustainability and Biomaterials Biorefineries, Biobased Materials and Recycling

CICECO

New materials from biomass residues (e.g bio-based PU foams from cork powder and other agro-forest residues, etc.)

High value extractives from biomass residues, fruits and algae: - Lipophilic extractives - Phenolics

New polymeric materials from renewable resources : - 2,5-Difurancarboxylic acid - Vegetable oils derivatives

New (nano)omposite materials from biopolymers: - Polysacharides, proteins, etc. - Other polymers - Inorganic nanophases

Outline

Hybrids with metal/ metal oxide

NPs

Surface functionalization/

modification

Transparent (Nano)

composites

Nano-structured materials

(in situ polymerization)

Outline


NPs


modification

Transparent (Nano)

composites



Hybrid materials with metal /metal oxide nanoparticles

NFC nanocomposites with Ag and ZnO NPs for antibacterial paper products

NFC nanocomposites with Ag and ZnO NPs for antibacterial paper products:

(1) Assembly of NFC and ZnO or Ag NPs using polyelectrolytes (PDDA, PSS) as macrolinkers

LBL assembly Paper coating

NFC 2.3 % solid content

2) Application of the obtained NFC/ZnO or NFC/Ag nanofillers in paper coating starch based formulations (16 % solid content)


NFC nanocomposites with Ag and ZnO NPs for antibacterial paper products:


Applications: functional packaging, bioactive coatings, etc.

S. aureus

ZnO <0.03% (w/w) Ag 4.5x10-5 % (w/w)

BC composites with Cu nanostructures (NPs and nanowires)



(1) Cu NPs; in situ synthesis (2) Cu nanowires; ex situ synthesis

+

Dispersion



- The use of Cu nanowires and BC has shown improved chemical stability against oxidation when exposed to normal ambient conditions

- The nanocomposites were stable for

periods of time (30 days) that makes the production of Cu-based products more attractive for emerging technologic applications as electronic nanopaper


3 days

5 months


Cu nanocomposites showed antibacterial action against both bacteria, however with a more marked effect in respect to K. pneumoniae

For both bacteria studied, BC/Cu nanowires nanocomposite present an antibacterial activity significantly lower (more than 2 log bacterial growth) in relation to the nanocomposite with copper NPs with similar copper amount (BC/Cu NPs2)


Outline


NPs


modification

Transparent (Nano)

composites



Transparent nanocomposite films based on nanocellulose fibers and polysacharides

starch chitosan pullulan

Transparent nanocomposite films

Transparent nanocomposites based on NFC (or BC) and chitosan


A fully green process

Casting 30ºC ventilated oven 16 h

Degassing

Dispersion Ultra-Turrax 20 500 rpm 30 min.

NFC or BC (up to 40%)

LCH - WSLCH HCH - WSHCH 1.5% (v/w)

HCH HCHBC10

Transparent nanocomposites based on NFC (or BNC) and chitosan


http://images.google.com/imgres?imgurl=http://www.daigger.com/assets/product_images/8759a.jpg&imgrefurl=http://www.daigger.com/catalog/department/d-Glass+Erlenmeyers/Glass+Erlenmeyers&usg=__xyll-uRoE3pE8tjcg3gLFUzCoA4=&h=256&w=154&sz=6&hl=pt-PT&start=17&um=1&tbnid=KPzarB-s4BAM7M:&tbnh=111&tbnw=67&prev=/images?q=erlenmeyers+photos&hl=pt-PT&rls=com.microsoft:pt:IE-SearchBox&rlz=1I7GGLL_en&sa=N&um=1

SEM images show the good dispersion of the NFC nanofibres at the surface of chitosan films

The good dispersion together with the good interfacial adhesion of CH and cellulose gave rise to nanocomposites with improved mechanical properties

CH

40 % 10 %

5%

Transparent nanocomposites based on NFC (or BNC) and chitosan


Multipolysaccharide (starch, nanocellulose fibers, chitosan) based nanocomposite films

Mechanical properties

(NFC or BC)

Thermal stability (starch)

Tranparency and

antimicrobial activity

(chitosan)


Transparent nanocomposites based on NFC (or BC) and pullulan


Improved thermal stability and mechanical properties


Transparent nanocomposites based on NFC (or BC) and pullulan

Applications of transparent thin nanocomposite films: functional packaging, biomedical applications (bioactive films/coatings, wound healing films, drug delivery systems, etc.) organic electronics…

Work in progress: “Self-standing chitosan based films as dielectrics in organic thin-film transistors” (eXPRESS Polymer letters 7, 2013, 960-965 “Nanocellulose as substrates for inkjet printing of organic thin film transistors”


Nanocellulose blends for paper coating Improved printability (gamut area, intercolour bleeding, etc.) and surface properties Aqueous coating compositions for use in surface treatment of cellulosic substrates WO 2011012934 A2


Outline Hybrids with metal/ metal oxide

NPs


modification

Transparent (Nano)

composites



Outline

Surface functionalization/modification

Antimicrobial and biocompatible BC membranes obtained by surface functionalization with aminoalkyl groups

NH2

Si OCH3

OCH3

H3CO

Immersion of BC membranein the solution

OH

OH

OH

OH

OH

Thermal Treatment

Acetone

2 hT=110 °C

Orbital stirring5h at 25 °C

Si

NH2

O

O

O

Si

NH2

O O

OSi

NH2

O OH

O

Si

O

O

BC

BC-NH2

0123456789

10

log

CFU

T24

S. aureus

Inoculated Broth + 5% NB

BC

BC-NH2

0

1

2

3

4

5

6

7

8

9

log

CFU

T24

E. coli

Inoculated Broth + 5% NB

BC

BC-NH2

Antimicrobial and biocompatible BC membranes obtained by surface functionalization with aminoalkyl groups

In addition, the bioactive nanostructured BC-NH2 membranes also present improved mechanical and thermal properties. Applications wound healing membranes, bioactive scaffolds, etc.


(Si 7.3%, N 3.4 % (w/w))

Surface hydrophobization of nanocellulose fibers using ILs as solvent media and catalysts

OH

O

H

RO

H

HORH O

OR

+ ? The use of cellulose fibers in the development of (nano)composites with thermoplastic matrices requires its preliminary surface chemical modification


Modification Reaction time

Acetic Anhydride 6 hours

Butyric Anhydride 4 days

Hexanoic Anhydride 11 days

Alkenyl succinic anhydrides 15 days

Hexanoyl chloride 24 hours

NN

FF

F

SO

O

N S

O

O

F

FF

catalyst

OOHO

OHO O

OH

O

OH

OH

OOHO

OHO O

OH

O

RO

HO

R

O

+

R O

O

R

O

or

P

F

FF

SO

O

N S

O

O

F

FF

solvent

80 ºC

O

R Cl

H2SO4 as catalyst



The modification reactions involved essentially the OH groups at the surface and the amorphous regions of the nanofibers (DS= 0.002-0.41)



Transparent nanocomposites based on bacterial nanocellulose and polylactic acid (PLA)


Transparent nanocomposites based on bacterial nanocellulose and PLA

Melting mixing

Acetylated BC (DS = 0.02)

PLA

- Higher homogeneity

- Thermal stability and

- Mechanical performance

- Low water up-take

Applications: packaging, biomedical products and devices, electronic devices etc.


(1, 3, 6 % (w/w))

Nanocellulose fibers/acrylic resins nanocomposites: comercial aqueous acrylic emulsions



Dispersion of BC into the acrylic emulsions

Solvent casting



0 100 200 300 400 500 600 700 8000,0

0,2

0,4

0,6

0,8

1,0DTGATGA

320 340 360 380 400 420 4400,0

0,2

0,4

0,6

0,8

1,0 414oC380oC

m/m

i

Temp (oC)

AC AC-BC1 AC-BC2.5 AC-BC5 AC-BC10

Improved thermal and mechanical properties

The good compatibility between unmodified fibers and the matrix is due in this case to the presence of surfactants used in the acrylic resin emulsion


Outline


NPs


modification

Transparent (Nano)

composites



Nanostructured materials

Nanostructured cellulose composites prepared by in situ polymerization techniques: ATRP

Step 1- BC functionalization with the ATRP initiator Step 2- ATRP grafting from the BC macroinitiator

Nanostructured cellulose composites prepared by in situ polymerization : ATRP


The grafting of the polymers from BC macroinitiator was confirmed by FTIR and 13C CP-MAS solid state



The characteristic tridimensional network of nano and microfibrils of BC is clearly visible on the surface and cross-section of grafted BC-membranes. After grafting an increment of the diameter of the cellulose fibrils is observed which is obviously associated with the chemical sleeving by the PMMA or PBA polymeric chains.



Grafting PMMA or PBA yielded highly hydrophobic membranes.

The values of the elastic moduli across the whole temperature range are lower than that of the ungrafted BC membrane Because acrylate polymers are more flexible than the BC nanofibrillar network



Nanostructured cellulose composites prepared by in situ polymerization : Radical polymerization


Nanostructured cellulose composites prepared by in situ radical polymerization


The success of the polymerization reaction inside BC membranes was confirmed by FTIR and NMR analysis

Nanostructured cellulose composites prepared by in situ radical polymerization Nanostructured materials

The cross-section micrographs of the nanocomposite films displayed the typical lamellar morphology of BC completely impregnated with PHEMA

BC/PHEMA/PEGDA (1:3:0)

BC/PHEMA/PEGDA (1:3:0)

BC/PHEMA/PEGDA (1:3:0.5)


The nanocomposites without cross-linker displayed a less homogenous morphology, with several unfilled parts, suggesting a considerable surface lixiviation of PHEMA during the washing step.



The nanocomposites present distinct degradation profiles and the considerable increments on the Ti and Tdmax a when compared with BC and PHEMA



BC/PHEMA nanocomposite films showed a considerably higher swelling ratio than BC membranes

Nanostructured materials Nanostructured cellulose composites prepared by in situ radical polymerization


BC/PHEMA/PEGDA (1:3:0.05) are not cytotoxic for ADSCs and seem to be ideal for harboring cell growth Can be seen as a promising materials for several biomedical applications, including the design of 3D matrices to maintain a cellular niche for stem cell-mediated tissue regeneration




Nanostructured cellulose composites prepared by in situ radical polymerization


The homogeneous distribution of PSSA through the entire membrane thickness is supportive that electrical percolation can be attained


The excellent mechanical behavior of pure BC is reflected on the composites both on magnitude of E´ (at least 20 times higher than that of Nafion) and on the thermomechanical stability


Drug delivery systems

Nanocellulose as new biopolymer systems for transdermal drug delivery (lidocaine, ibuprofen, caffeine, diclofenac)

drug – Glycerol Solution, 1h

Wet BC membrane

Oven dried (30ºC)

No drug agglomerates

Good dispersion

Nanocellulose as a new biopolymer system for transdermal drug delivery (lidocaine, ibuprofen, caffeine, diclofenac)

SEM

Lidocaine Ibuprofen


Nanocellulose as a new biopolymer system for transdermal drug delivery (lidocaine, ibuprofen, caffeine, diclofenac)

In vitro permeation tests

- BC membrane with drugs

- Drugs solutions

- Commercial gels or patches

Human skin Franz cell

8h, 37ºC, PBS (phosphate buffer) drug determination: UV-Vis

Pharmaceutical Forms


- The permeation rate of drugs in nanocellulose membranes depends strongly on its nature. - This methodology can be successfully applied for the dermal administration of several drugs, regarding the release profile and ease of application.


Conlusions

NanoCellulose fibers… A unique biomacromolecular material Multiple opportunities …Sustainable Development

Thanks for you attention….

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