TY  - JOUR
AU  - Jiménez, V.A.
AU  - Gavín, J.A.
AU  - Alderete, J.B.
T1  - Scaling trend in diffusion coefficients of low generation G0-G3 PAMAM dendrimers in aqueous solution at high and neutral pH
LA  - eng
PY  - 2012
SP  - 123
EP  - 128
T2  - Structural Chemistry
SN  - 1040-0400
VL  - 23
IS  - 1
AB  - Aqueous solution diffusion coefficients for G0-G3 PAMAM dendrimers were determined from DOSY-NMR spectroscopy at high and neutral pH. The study was performed in a dilute regime and diffusion coefficients at infinite dilution (D 0) were estimated from the variation of diffusion coefficients with dendrimer concentration. Hydrodynamic radii (Rh) for each dendrimer were estimated from D 0 using the Stoke-Einstein relationship at both pH. According to D 0 and R h values, the structure of G0-G1 PAMAM dendrimers is almost insensitive to pH variations, whereas G2-G3 PAMAM dendrimers undergo swelling at neutral pH, due to surface amino groups protonation. Experimental diffusion coefficients show a scaling trend with the number of dendrimer atoms (N), with scaling laws of the type D 0 ∞ N a, where a takes values of -0.39 and -0.50 at pH 12 and 7, respectively. For the first time, experimental data accounts for the scaling behavior of aqueous diffusion coefficients for low generation PAMAM dendrimers, as previously reported from molecular dynamics simulations. © Springer Science+Business Media, LLC 2011.
DO  - 10.1007/S11224-011-9844-6
UR  - https://portalciencia.ull.es/documentos/5e3c379929995246bbf5e86e
DP  - Dialnet - Portal de la Investigación
ER  -