Adaptive 2D and Pseudo-2D Systems: Molecular, Polymeric, and Colloidal Building Blocks for Tailored Complexity

Abstract

Two-dimensional and pseudo-2D systems come in various forms. Membranes separating protocells from the environment were necessary for life to occur. Later, compartmentalization allowed for the development of more complex cellular structures. Nowadays, 2D materials (e.g., graphene, molybdenum disulfide) are revolutionizing the smart materials industry. Surface engineering allows for novel functionalities, as only a limited number of bulk materials have the desired surface properties. This is realized via physical treatment (e.g., plasma treatment, rubbing), chemical modifications, thin film deposition (using both chemical and physical methods), doping and formulation of composites, or coating. However, artificial systems are usually static. Nature creates dynamic and responsive structures, which facilitates the formation of complex systems. The challenge of nanotechnology, physical chemistry, and materials science is to develop artificial adaptive systems. Dynamic 2D and pseudo-2D designs are needed for future developments of life-like materials and networked chemical systems in which the sequences of the stimuli would control the consecutive stages of the given process. This is crucial to achieving versatility, improved performance, energy efficiency, and sustainability. Here, we review the advancements in studies on adaptive, responsive, dynamic, and out-of-equilibrium 2D and pseudo-2D systems composed of molecules, polymers, and nano/microparticles.

Formation of Hydrophobic–Hydrophilic Associates in the N-Vinylpyrrolidone and Vinyl Propyl Ether Copolymer Aqueous Solutions

“…A correspondence between the quantity under the exponent in Equation ( 13) and the normalized concentration x can be established. Expression (20) can be reformulated as:…”

“…In the current juncture, the rationale for conceiving programmable architectures that elicit specific responses contingent upon predefined combinations of thermodynamic variables, or their sequential temporal permutations, is eminently justified [18][19][20]. Salient trends in this direction are already perceptible.…”

Stimuli-Responsive Langmuir Films Composed of Nanoparticles Decorated with Poly(N-isopropyl acrylamide) (PNIPAM) at the Air/Water Interface

“…“Dynamic systems” require external stimuli, pushing them out of equilibrium. “Adaptive materials” present particular responses to given external stimuli and transition between equilibrium states, equilibrium and nonequilibrium states, or two or more nonequilibrium states . The review also gives a contemporary overview of adaptive two-dimensional (2D) and pseudo-2D systems.…”

Nanostructures and Thin Films of Poly(Ethylene Glycol)-Based Surfactants and Polystyrene Nanocolloid Particles on Mica: An Atomic Force Microscopy Study

“…One area that is still relatively unexplored is the self-assembly of polymeric colloidal [14,15] and in particular nanocolloidal particles [16] on surfaces and the formation of associated nanostructures and thin films. This has the potential to achieve nanostructures and nanopatterns for advanced products such as high-density, defect-free data storage devices, sensors, and biochips made for a substantially lower cost than at the present and using more environmentally friendly materials and processes (suspensions of particles in water) [17][18][19][20]. In order for these colloidal particles to maintain their dispersion in a liquid suspension and not sediment out by flocculation, they must have repulsive interactions to counteract the ubiquitous attractive van der Waals forces.…”