Calculation of Conformational Properties and Rouse Relaxation Times of PAMAM‐EDA Dendrimers under Different pH Conditions. Issue 4 (17th May 2016)

• Record Type: Journal Article
• Authors: Freire, Juan J.; Rubio, Ana M.; McBride, Carl
• Is Part Of: Macromolecular theory and simulations. Volume 25:Issue 4(2016)
• Page Start: 403
• Page End: 412
• Publication Date: 2016-05-17
• Subjects: dendrimers -- hydrodynamic properties -- Monte Carlo -- relaxation times; Macromolecules -- Periodicals; Polymers -- Periodicals; Polymerization -- Periodicals; Macromolécules -- Périodiques; 547.705
• DOI: 10.1002/mats.201600012
• Languages: English
• ISSNs: 1022-1344

Abstract

Abstract : A Monte Carlo study is performed for different properties of PAMAM‐EDA dendrimers using a coarse‐grained model. This study calculates different equilibrium properties and gives theoretically‐based estimations of hydrodynamic and dynamic properties. A discussion of the influence of protonation is included together with a comparison with existing experimental data. Abstract : A Monte Carlo study has been performed for protonated and non‐protonated coarse‐grained PAMAM‐EDA of generations ( G ) ranging from 2 to 6. This study calculates sizes, asphericities, and global and external dendrimer density profiles that confirm features previously found in other studies. It is shown that form factors do not change significantly with protonation. Diffusion coefficients, intrinsic viscosities, and Rouse relaxation times are computed as conformational averages. The hydrodynamic properties and their change with protonation are in good agreement with available experimental data. Some differences between the neutral and protonated molecules are noticeable in the case of the relaxation times corresponding to the higher generation numbers ( G > 4). These features indicate that pH may play a role in the internal dynamics of dendrimers. The complex modulus curves have also been computed. When in reduced units to discount size effects, the protonation effect is seen to be very small.