title: Synthesis and characterization of pH-responsive and fluorescent poly (amidoamine) dendrimer-grafted cellulose nanocrystals.
abstract: Poly (amidoamine) (PAMAM) dendrimers have found promising applications in biomedicine and in the encapsulation of inorganic nanoparticles. G6 PAMAM dendrimer-grafted cellulose nanocrystals (CNC-PAMAM) were prepared via a simple carbodiimide-mediated amidation process and they displayed pH-responsive and fluorescent characteristics as confirmed by zeta potential, transmittance, isothermal titration calorimetry (ITC), and fluorescence spectroscopy. Stable aqueous dispersions of CNC-PAMAM were obtained at pH⩽4 and pH⩾10, driven by electrostatic repulsion from positive charge and negative charge respectively. However, large aggregates were formed at pH values from 5 to 9 due to electrostatic attraction. In addition, strong blue fluorescent emission was observed, and the fluorescent behaviour of CNC-PAMAM was influenced by the formation of aggregates. The pH-responsive and fluorescent properties of CNC-PAMAM may be suitable for their applications in pH-responsive nanodevices, fluorescent-based pH sensors, optical markers, and nanoreactors for the encapsulation of inorganic nanoparticles.
authors: Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada.
authors: L
authors: L
authors: Chen
authors: Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada.
authors: W
authors: W
authors: Cao
authors: Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada.
authors: N
authors: N
authors: Grishkewich
authors: CelluForce Inc., 625, Président-Kennedy Ave, Montreal, Quebec H3A 1K2, Canada.
authors: R M
authors: RM
authors: Berry
authors: Department of Chemical Engineering, Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Ave W, Waterloo, ON N2L 3G1, Canada. Electronic address: mkctam@uwaterloo.ca.
authors: K C
authors: KC
authors: Tam
mesh_terms: D002482:Cellulose / Q000031:analogs & derivatives / Q000138:chemical synthesis* / Q000737:chemistry; D050091:Dendrimers / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry*
chemical_list: D050091:Dendrimers; D005456:Fluorescent Dyes; C531249:Poly(amidoamine); D011073:Polyamines; D002482:Cellulose
keywords: Cellulose nanocrystals; Fluorescence; Poly (amidoamine) dendrimer; Surfactant interactions; pH responsive