TY - JOUR
T1 - Structural response of polyelectrolyte dendrimer towards molecular protonation
T2 - The inconsistency revealed by SANS and NMR
AU - Hong, Kunlun
AU - Liu, Yun
AU - Porcar, Lionel
AU - Liu, Dazhi
AU - Gao, Carrie Y.
AU - Smith, Gregory S.
AU - Herwig, Kenneth W.
AU - Cai, Sheng
AU - Li, Xin
AU - Wu, Bin
AU - Chen, Wei Ren
AU - Liu, Li
PY - 2012/2/15
Y1 - 2012/2/15
N2 - Polyamidoamine (PAMAM) dendrimers and their charged state in deuterium oxide have been investigated with proton pulsed field gradient diffusion nuclear magnetic resonance (PFG-NMR) and small-angle neutron scattering (SANS) techniques. NMR measurements suggest that significant variation of the hydrodynamic radius, calculated by the Stokes-Einstein relation with appropriate surface conditions, is observed upon increasing the molecular protonation. However, a comparative SANS experiment indicates little dependence of the dendrimer global size, in terms of its radius of gyration, on molecular protonation. The inconsistency indicates the necessity of incorporating the effect of molecular interface modification and molecular porosity provided by dressed counterions, when dynamical measurements are used for the determination of the structural characteristics of ionic soft colloids even in dilute suspensions.
AB - Polyamidoamine (PAMAM) dendrimers and their charged state in deuterium oxide have been investigated with proton pulsed field gradient diffusion nuclear magnetic resonance (PFG-NMR) and small-angle neutron scattering (SANS) techniques. NMR measurements suggest that significant variation of the hydrodynamic radius, calculated by the Stokes-Einstein relation with appropriate surface conditions, is observed upon increasing the molecular protonation. However, a comparative SANS experiment indicates little dependence of the dendrimer global size, in terms of its radius of gyration, on molecular protonation. The inconsistency indicates the necessity of incorporating the effect of molecular interface modification and molecular porosity provided by dressed counterions, when dynamical measurements are used for the determination of the structural characteristics of ionic soft colloids even in dilute suspensions.
UR - http://www.scopus.com/inward/record.url?scp=84856397306&partnerID=8YFLogxK
U2 - 10.1088/0953-8984/24/6/064116
DO - 10.1088/0953-8984/24/6/064116
M3 - Article
C2 - 22277898
AN - SCOPUS:84856397306
SN - 0953-8984
VL - 24
JO - Journal of Physics Condensed Matter
JF - Journal of Physics Condensed Matter
IS - 6
M1 - 064116
ER -