HYBRID EVENT: You can participate in person at Orlando, USA or Virtually from your home or work.

6th edition of World Nanotechnology Conference

April 24-25, 2023

April 24 -26, 2023 | Orlando, USA
World Nano 2020

Nano-structuring of polymer blends at the interface driven by topology

Giuseppe Pellicane, Speaker at Nanomaterials Conference
UKZN And Universita’ Degli Studi Di Messina, South Africa
Title : Nano-structuring of polymer blends at the interface driven by topology

Abstract:

Physical techniques for surface modification of plastics use surface-active agents, which can self-assemble at the surface. Many techniques, which are important in modern technologies, use polymer blends, and there is considerable interest to understand the extent the composition of the surface layer differs from that in the bulk for molten polymer mixtures. Dynamical and structural properties of polymers in the melt state are strongly influenced by molecular architecture and blending polymers with different molecular topologies could be potentially exploited to control interfacial segregation of the polymer film, and to achieve optimal mechanical properties of the plastic material. However, a deep understanding of the role of chain architecture and molecular mass in determining which species preferentially adsorb at a given interface is lacking. Experiments to resolve the matter are typically conducted by mixing polymers possessing the same repeat chemistry, but different molecular architecture. Here we show the results obtained in large-scale molecular dynamics simulations of linearcyclic polymer films, and we find clear evidence of enhancement of linear polymers at the interface, in agreement with recent experimental results. The behavior predicted by the self-consistent field theory (SCF), i.e., enhancement of cyclic polymers at the interface, emerges for relatively long chains. In our presentation, we provide a picture of the microscopic mechanisms through which the chain length arbitrates the competition between the different packing constraints imposed by the loop and linear geometry of the two polymers. We also discuss the role of enthalpic and entropic factors of the interfacial free energy of the system in determining which species in the blend preferentially adsorbs at the interface.

Biography:

Dr Pellicane is an Associate Professor in the School of Chemistry and Physics, at the University of Kwazulu-Natal (South Africa), where he works since 2011. He took his PhD in Physics at the University of Messina (Italy) in 2001. He is the author of more than 60 peer-reviewed articles indexed in the web of Science – core collection database. His field of expertise is the theory and computer simulation of simple/complex fluids. He has acted as a reviewer for several international journals operating in the field of chemical physics, physical chemistry, theoretical condensed matter physics, polymer science.

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