Dendrimer directed assembly of dicarboxylated hairy nanocellulose

Mandana Tavakolian; Jade Lerner; Fernando Medina Tovar; Jérémy Frances; Theo G M van de Ven; Ashok Kakkar

doi:10.1016/j.jcis.2019.01.100

Dendrimer directed assembly of dicarboxylated hairy nanocellulose

J Colloid Interface Sci. 2019 Apr 1:541:444-453. doi: 10.1016/j.jcis.2019.01.100. Epub 2019 Jan 23.

Authors

Mandana Tavakolian¹, Jade Lerner², Fernando Medina Tovar³, Jérémy Frances³, Theo G M van de Ven⁴, Ashok Kakkar⁵

Affiliations

¹ Department of Chemical Engineering, McGill University, 3610 University Street, Montréal, QC H3A 0C5, Canada; Pulp and Paper Research Center, McGill University, 3420 University Street, Montréal, QC H3A 2A7, Canada; Québec Centre for Advanced Materials (QCAM), 3420 University Street, Montréal, QC H3A 2A7, Canada. Electronic address: Mandana.tavakolian@mail.mcgill.ca.
² Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, QC H3A 0B8, Canada. Electronic address: Jade.lerner@mail.mcgill.ca.
³ Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, QC H3A 0B8, Canada.
⁴ Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, QC H3A 0B8, Canada; Pulp and Paper Research Center, McGill University, 3420 University Street, Montréal, QC H3A 2A7, Canada; Québec Centre for Advanced Materials (QCAM), 3420 University Street, Montréal, QC H3A 2A7, Canada. Electronic address: theo.vandeven@mcgill.ca.
⁵ Department of Chemistry, McGill University, 801 Sherbrooke Street West, Montréal, QC H3A 0B8, Canada; Québec Centre for Advanced Materials (QCAM), 3420 University Street, Montréal, QC H3A 2A7, Canada. Electronic address: ashok.kakkar@mcgill.ca.

PMID: 30711638
DOI: 10.1016/j.jcis.2019.01.100

Abstract

Hypothesis: Dendrimer-directed assembly of electrosterically stabilized nanocrystalline cellulose (ENCC) to form network structures was studied. ENCC is a member of the family of hairy nanocelluloses and consists of a crystalline rod and dicarboxylated cellulose chains ("hairs") protruding from both ends, which are very reactive. We hypothesized that covalent linking of ENCC and dendrimers should lead to self-assembled hybrid network structures in which dendrimeric nodes connect cellulose nanorods.

Experiments: Polyamidoamine (PAMAM) dendrimers were covalently linked to ENCC by a bioconjugation reaction with different ratios of ENCC to PAMAM. To control the self-assembly process and prevent aggregation, acid hydrolysis of ENCC was performed to obtain crew-cut ENCC with shorter hairs and less negative charge. The formation of self-assembled structures from different PAMAM concentrations were analyzed using atomic force microscopy.

Findings: It was observed that depending on the concentration of PAMAM, various linear, star-shaped, and closed-loop structures were formed. Also, networks were formed with dendrimers acting as the nodes, connecting long cellulose rods, thus producing a network with a characteristic length of around 100-200 nm, which is difficult to obtain otherwise. We have demonstrated that the reactions of dendrimers with ENCC are solely occurring at the hairs and not at the crystalline regions.

Keywords: Electrosterically stabilized nanocrystalline cellulose; Hairy nanocrystalline cellulose; Nanostructure; PAMAM dendrimer; Self-assembly.