FLEXIBILITY OF CELLULOSE NANOCRYSTAL NETWORKS IN RESPONSE TO WATER VAPOR ELINA NIINIVAARA1, MARCO FAUSTINI2, TEKLA TAMMELIN3, HEIKE M.A. EHMANN4, STEFAN SPIRK4 AND EERO KONTTURI1 1 DEPARTMENT OF FOREST PRODUCTS TECHNOLOGY, SCHOOL OF CHEMICAL TECHNOLOGY, AALTO UNIVERSITY, FINLAND 2 UNIVERSITÉ PIERRE ET MARIE CURIE, LABORATORIE CHIMIE DE LA MATIERE CONDENSÉE – COLLÈGE DE FRANCE, FRANCE 3 VTT – TECHNICAL RESEARCH CENTER OF FINLAND, HIGH PERFORMANCE FIBRE PRODUCTS, FINLAND 4 INSTITUTE FOR CHEMISTRY AND TECHNOLOGY, GRAZ UNIVERSITY OF TECHNOLOGY, AUSTRIA

OBJECTIVES Water vapor makes up approximately 2 – 3 % of the Earths atmosphere and as such its interactions with surfaces is of importance. COST ACTION FP1105 SAN SEBASTIAN 26TH MAY 2015

OBJECTIVES Water vapor makes up approximately 2 – 3 % of the Earths atmosphere and as such its interactions with surfaces is of importance. Water vapor adsorption also important in various applications: Packaging materials Pharmaceuticals Corrosion research Moisture sensors COST ACTION FP1105 SAN SEBASTIAN 26TH MAY 2015

OBJECTIVES IN THIS STUDY THE WATER VAPOR SORPTION BEHAVIOR OF CNC ULTRATHIN FILMS WAS STUDIED USING SPECTROSCOPIC ENVIRONMENTAL ELLIPSOMETRIC POROSIMETRY AND A QUARTZ CRYSTAL MICROBALANCE WITH DISSIPATION MONITORING. COST ACTION FP1105 SAN SEBASTIAN 26TH MAY 2015

HIGHLIGHTS HYDRATION OF CNC NETWORK OCCURS AROUND THE CRYSTALS NOT AS WATER CONDENSATION IN THE VOIDS BETWEEN CRYSTALS THICKNESS OF CNC FILM THICKNESS OF CNC FILM AND ADSORBED WATER VAPOR WATER VAPOR ADSOPRTION COST ACTION FP1105 SAN SEBASTIAN 26TH MAY 2015

HIGHLIGHTS THREE MOLECULAR LAYERS OF WATER ENVELOPE EACH CNC IN THE NETWORK. 7 nm FRONT VIEW 7 nm 140 nm 7 nm + (3 + 3) MONOLAYERS OF WATER, 9 nm FRONT VIEW 140 nm 9 nm CNC HYDRATION COST ACTION FP1105 SAN SEBASTIAN 26TH MAY 2015

THANK YOU FUNDING Aalto University Academy of Finland WoodWisdom – Net (Tunable Films project)