Nanocellulose

• Cellulose Nanofibrils (CNF): web like structure; Spaghetti

• Cellulose Nanocrystals (CNC): individual crystals/rods

• Bacterial cellulose: Cellulse of high purity

• Wood fibers

• Vegetables

• Plants

• Masuko Grinder

• Homogenizer: shear forces for shreddig fibers

• Pre-treatments: Acid, Enzymes, TEMPO

• HCI + H2SO4 —> Heating —> Centrifugation —> Dialysis —> Sonication

• 0.7/(L/d)

• Higher L/D —> lower nanocrystals content

• Higher L/D the higher Youngs moudlus and tensile strength

• Advantages: leightweightm builds networks, high strenth, stiffness, water storage, high surface area, high reactivity, barrier properties

• Strong hydrophilic character is problematic —> lack of compatability with hydrophobic polymer matrices

• Restricted application field

• Esterfication

• Oxidation

• Estherficaation, alcohol + alcohol

• Silyation with alkoxysilanes to tailor polarity of NFC

• Evaporation: Liquid —> Gas

• Prepared by vacuum filtration and water evaporation

• 2D network of Cellulose nanofibers

• 1. Dilution of NFC suspension —> 2. Vacuum filtration —> 3. Drying

• Properties: transparent, smooth, barrier against oxygen, density

• Applications: Packaging, displays, coatings, adhesives

• Freeze drying: Ice crystals sublimate directy into gaseous state

• Cellular structure with nanopaper cell wall

• Pores: reflect ice crystal formation during freezing step

• Low specific surface are, mechanical properties tunable by density, ductile, rough

• Applications: packaging, insulation, biomedicine

• Supercritical drying: über kritischer temperatur und druck

• Cellular structure with nanopaper cell wall

• Separation of liquids from solids without affecting structure

• Aerogek; liquid omponent replaced by air without affection structure

• Applications: filtration, gas separation, insulation

Elastic component > Viscous component