PhotoSoftMat · Photo-controlled two-dimensional soft materials from microgel particles at liquid interfaces
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2020-10-01 → 2022-09-30
- EU contribution
- €191,149
- Participants
- 1
- Scheme
- MSCA-IF
Lines connect the coordinator with its partners.
Results in brief
Photo-controlled two-dimensional soft materials from microgel particles at liquid interfaces
This MSCA IF broadly covered various topics of relevance for materials science, physical chemistry and soft matter science. In particular, it focussed on studying some fundamental aspects related to the adsorption and interactions between colloidal particles at fluid, air-water or oil-water, interfaces; which are directly related to a variety of materials and processes. Particle adsorption at a fluid interface is responsible for the stabilization of foams and emulsions, or the encapsulation, structuring and manipulation of liquids, and therefore finds numerous applications in oil recovery, food and cosmetic industry, etc. Particle assembly on planar fluid surfaces allows the production of two-dimensional (2D) materials that find uses in catalysis, optics and surface science, to name a few relevant examples. Currently, alongside with hard, mechanically rigid colloids, soft micro and nanoparticles (microgels) are gaining much attention because of their responses to multiple stimuli and environmental conditions (temperature, pH, concentration, pressure, solvent quality, etc.). This allows tuning their softness, shape and interparticle interactions at will, ultimately producing responsive materials endowed with additional functionalities, including complex phase behaviours and rheological properties stemming from their extent of interpenetration, deformation and compression. Sensitivity to environmental conditions and stimuli is translated to 2D when microgels are adsorbed at fluid interfaces, where they can be used as powerful foams and emulsions stabilizers, or to produce 2D materials of interest for coatings, optics and colloidal lithography, with superior advantages over the use or hard particles. Overall, this project addressed three fundamental questions in the research field: 1) how does the particle’s internal structure, as designed at the synthesis level, influence its structural and mechanical properties upon interfacial confinement?; 2) which is the exact 3D conformation of a soft object adsorbed at a fluid interface?; and 3) what is the effect of various system parameters (internal polymer density profile, solution temperature and choice of the organic top phase) on the final conformation of an adsorbed microgel? These are at present driving questions in the field, and have been addressed with fundamental contributions stemming from this research project.
Data: CORDIS, © European Union
Project objective
Microgels are valuable building blocks both for investigating colloidal phase transitions and for the fabrication of complex materials that react and adapt to external stimuli. In particular, liquid interfaces are perfect two-dimensional (2D) templates for microgel assembly because of the long-range ordered organization that can be achieved in a fast and reliable manner. The structure of microgel assemblies at liquid interfaces can be precisely controlled by changing external parameters (e.g, temperature, pH, surface pressure). The microgels volume and compressibility can be modulated, in turn affecting their mutual interactions and final organization. The goal of this multidisciplinary proposal is to develop novel systems where light actuation can be coupled in to control microgel properties at liquid interfaces. Up to now, the external stimuli used to control 2D microgel assemblies had several limitations: the lack of spatial resolution, a poor control over the response time, and the irreversibility of the transitions. With the proposed systems, an optical trigger will allow the external control of the inter-particle interactions as well as of the particle size and compressibility with exceptional spatial and temporal resolution. Two synthetic routes are considered: i) covalent modification of the microgel structure with the addition of light-responsive co-monomers; ii) mixing of microgels with photoresponsive surfactants. Different responses are offered by these two strategies. In the former case, unprecedented local control over microgel assemblies can be achieved, opening the way to novel studies over 2D phase transitions. In the latter case, a composite system is proposed, where microgel properties, as well as macroscopic surface flows, can be manipulated by light actuation. Ultimately, reconfigurable colloidal structures endowed with multiple properties that can be advantageously switched in a fast and local manner by the external stimulation are envisioned.
Original text from CORDIS.
Participants
- EIDGENOESSISCHE TECHNISCHE HOCHSCHULE ZUERICH · ZuerichCoordinatorSwitzerland
Links
Data: CORDIS, © European Union