@article{ISI:000430973300020,
 abstract = {The adsorption of PAMAM dendrimers at solid/water interfaces has been
extensively studied, and is mainly driven by electrostatic and van der
Waals interactions between the substrate and the dendrimers. However,
the pH dependence of the adsorption driven predominantly by the van der
Waals interactions is poorly explored, although it is crucial for
investigating the potentiality of these dendrimers in supercapacitors
and surface patterning. Motivated by this aspect, we have studied the
adsorption behavior of PAMAM dendrimers of generations 2 (G2) to 5 (G5)
with pH and salt concentration variation, on a charge neutral graphene
substrate, using fully atomistic molecular dynamics simulations. The
instantaneous snapshots from our simulations illustrate that the
dendrimers deform significantly from their bulk structures. Based on
various structural property calculations, we classify the adsorbed
dendrimer morphologies into five categories and map them to a phase
diagram. Interestingly, the morphologies we report here have striking
analogies with those reported in star-polymer adsorption studies. From
the fractional contacts and other structural property analyses we find
that the deformations are more pronounced at neutral pH as compared to
high and low pH. Higher generation dendrimers resist deformation
following the deformation trend, G2 > G3 > G4 > G5 at any given pH
level. As the adsorption here is mainly driven by van der Waals
interactions, we observe no desorption of the dendrimers as the salt
molarity is increased, unlike that reported in the electrostatically
driven adsorption studies.},
 author = {Gosika, Mounika and Maiti, Prabal K.},
 doi = {10.1039/c8sm00179k},
 eissn = {1744-6848},
 issn = {1744-683X},
 journal = {SOFT MATTER},
 month = {MAR 14},
 number = {10},
 orcid-numbers = {Maiti, Prabal/0000-0002-9956-1136
Gosika, Mounika/0000-0002-6996-2051},
 pages = {1925-1938},
 researcherid-numbers = {Maiti, Prabal/B-6335-2009
},
 times-cited = {8},
 title = {pH and generation dependent morphologies of PAMAM dendrimers on a
graphene substrate},
 unique-id = {ISI:000430973300020},
 volume = {14},
 year = {2018}
}