Smart Polymer Nanocomposites (SPACE)
Abstract
Polymer nanocomposites (PNCs) are hybrid materials consisting of a polymeric matrix incorporating nanoparticles (NPs). They couple many key properties of polymers, such as flexibility, processability and ductility, to enhanced thermal and mechanical stability as well as optical, electrical, magnetic and other intriguing properties sparked by the presence of NPs. As such, PNCs are paving the path for next-generation smart nanomaterials in energy efficiency and storage, environmental remediation, textile, food and biomedical applications. Incorporating nano-sized rather than micron-sized fillers poses a notable difference in terms of polymer/particle interface and interactions. In particular, NPsÕ surface area-to-volume ratio is orders of magnitude larger than that provided by their micron-sized counterparts, with the opportunity of generating new properties at a relatively low loading. Consequently, the successful design of PNCs exhibiting specific properties relies on the full understanding and control of complex structure-properties relationships stemming from the interactions established at the nanoscale (precisely at the NP/polymer interface) that influence the polymer microstructure and impact the materialÕs response at the macroscale. The aim of SPACE is investigating the origin of such structure-properties relationships to develop PNCs that exhibit controlled responses to external stimuli. More specifically, SPACE will investigate how the presence of responsive NPs, embodying switchable functionalities, can lead to smart PNCs able to selectively respond to an external field and activate specific properties. The most ambitious challenge is incorporating two distinct sets of NPs, each activating a specific functionality according to the nature and intensity of the external field and thus providing multifunctional PNCs with enhanced protective and sensing capabilities. Molecular simulation techniques will be employed to unveil the driving forces determining the properties activated at the NP/polymer interface and control the effect of incorporating functional NPs on the macroscopic response of PNCs. SPACE will consist of four work packages (WPs) whose scientific objectives are described next. WP1 and WP2 will provide the model to mimic the behaviour of homopolymers and block copolymers embodying nanodimers, nanorods or their mixture. Structural, dynamical and transport properties of these PNCs will be investigated in detail. In WP3 and WP4, SPACE will focus on the effect of an external electric field on the PNCs modelled and characterised in WP1 and WP2. In particular, WP4 will apply the fundamentals unveiled by WP2 in order to accurately control NPsÕ position and orientation in a polymer that is able to self-assemble into separate, ordered domains, selectively interacting with guest NPs or a portion of their surface. Depending on its intensity, the external field will modify the PNC s macroscopic response by acting on the NPs and modifying their space distribution and orientation in the host polymer. As such, WP3 and WP4 will deliver a fundamental insight into how an external electric field can activate specific functionalities. Aware that the genesis of most macroscopic properties is in the NP/polymer interface, we will specifically investigate how the polymer chainsÕ structure and mobility modify in the vicinity of the NPÕs surface. Achieving these scientific objectives will disclose the origins of the delicate balance between enthalpic and entropic forces that determine the range and strength of NP/polymer interactions at the nanoscale, mold the response of the material at the macroscale and thus allow us to design PNCs exhibiting desired properties for ad-hoc applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 24, 2023
- Source ID
- W911NF2310099
Entities
People
- Alessandro Patti
Organizations
- Army Contracting Command
- United States Army
- University of Granada