Synthesis of amine functionalized cellulose nanocrystals: optimization and characterization.
A simple protocol was used to prepare amine functionalized cellulose nanocrystals (CNC-NH2). In the first step, epichlorohydrin (EPH) was reacted with ammonium hydroxide to produce 2-hydroxy-3-chloro propylamine (HCPA). In the next step, HCPA was grafted to CNC using the etherification reaction in an organic solution media. Various reaction parameters, such as time, temperature, and reactant molar ratio were performed to determine the optimal reaction conditions. The final product (CNC-NH2(T)) was dialyzed for a week. Further purification via centrifugation yielded the sediment (CNC-NH2(P)) and supernatant (POLY-NH2). The presence of amine groups on the surface of modified CNC was confirmed by FTIR and the amine content was determined by potentiometric titration and elemental analysis. A high amine content of 2.2 and 0.6 mmol amine/g was achieved for CNC-NH2(T) and CNC-NH2(P), respectively. Zeta potential measurements confirmed the charge reversal of amine CNC from positive to negative when the pH was increased from 3 to 10. The flocculation of amine functionalized CNC due to its interactions with a negatively charged surfactant namely, sodium dodecyl sulfate (SDS) was investigated at pH 4. It showed promising results for applications, such as in flocculation of fine dispersions in water treatment. This simple and versatile synthetic method to produce high amine content CNC can be used for further conjugation as required for various applications.
Dept. of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Seyedeh Parinaz
SP
Akhlaghi
Dept. of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Masuduz
M
Zaman
Dept. of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Nishil
N
Mohammed
Chemistry Institute, University of Campinas, PO Box 6154, 13083-970 Campinas, SP, Brazil.
César
C
Brinatti
Dept. of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
Rasim
R
Batmaz
CelluForce Inc., 625, Président-Kennedy Avenue, Montreal, QC H3A 1K2, Canada.
Richard
R
Berry
Chemistry Institute, University of Campinas, PO Box 6154, 13083-970 Campinas, SP, Brazil.
Watson
W
Loh
Dept. of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada. Electronic address: mkctam@uwaterloo.ca.
Kam Chiu
KC
Tam
D000588:Amines / Q000737:chemistry*; D002482:Cellulose / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry*
D000588:Amines; D002482:Cellulose
Amine modified cellulose nanocrystals; Characterization; Surface functionalization