ABSTRACT
Biological membranes exhibit the ability to self-repair and dynamically change their shape while remaining impermeable. Yet, these defining features are difficult to reconcile with mechanical robustness. Here, we report on the spontaneous formation of a carbon nanoskin at the oil-water interface that uniquely combines self-healing attributes with high stiffness. Upon the diffusion-controlled self-assembly of a reactive molecular surfactant at the interface, a solid elastic membrane forms within seconds and evolves into a continuous carbon monolayer with a thickness of a few nanometers. This nanoskin has a stiffness typical for a 2D carbon material with an elastic modulus in bending of more than 40-100 GPa; while brittle, it shows the ability to self-heal upon rupture, can be reversibly reshaped, and sustains complex shapes. We anticipate such an unusual 2D carbon nanomaterial to inspire novel approaches towards the formation of synthetic cells with rigid shells, additive manufacturing of composites, and compartmentalization in industrial catalysis.
Subject(s)
Carbon , Nanostructures , Elastic Modulus , Membranes , Surface-Active AgentsABSTRACT
Novel preparative approaches towards lamellar nanocomposites of carbon and inorganic materials are relevant for a broad range of technological applications. Here, we describe how to utilize the co-assembly of a liquid-crystalline hexaphenylene amphiphile and an aluminosilicate precursor to prepare carbon-aluminosilicate nanocomposites with controlled lamellar orientation and macroscopic order. To this end, the shear-induced alignment of a precursor phase of the two components resulted in thin films comprising lamellae with periodicities on the order of the molecular length scale, an "edge-on" orientation relative to the substrate and parallel to the shearing direction with order on the centimeter length scale. The lamellar structure, orientation, and macroscopic alignment were preserved in the subsequent pyrolysis that yielded the corresponding carbon-aluminosilicate nanocomposites.
ABSTRACT
Oligoynes with two or more conjugated carbon-carbon triple bonds are useful precursors for carbon-rich nanomaterials. However, their range of applications has so far been severely limited by the challenging syntheses, particularly in the case of oligoynes with functional groups. Here, we report a universal synthetic approach towards both symmetric and unsymmetric, functionalized hexaynes through the use of a modified Eglinton-Galbraith coupling and a sacrificial building block. We demonstrate the versatility of this approach by preparing hexaynes functionalized with phosphonic acid, carboxylic acid, ammonium, or thiol head groups, which serve as neutral, cationogenic, or anionogenic interfacially active groups. We show that these hexaynes are carbon-rich amphiphiles or bolaamphiphiles that self-assemble at liquid-liquid interfaces, on solid surfaces, as well as in aqueous media.
ABSTRACT
New therapeutics for glioblastoma multiforme and our ability to deliver them using efficient nanocarriers constitute topical areas of research. We report a comparative study of temozolomide and quercetin in the treatment of glioblastoma (GBM) in three-dimensions, and their incorporation into micelles obtained from synthetically articulated architectural copolymers, and a commercially available linear polymer poly(ethylene glycol)-poly(lactic-co-glycolic acid) (PEG-PLGA). A versatile synthetic methodology to telodendrimers, which can be easily adapted to the needs of other therapeutic interventions, is presented. These dendritic block copolymers self-assemble into micelles and offer a platform for single or combination drug therapy. Telodendrimer micelles loaded with quercetin did not exhibit superior cell killing effect over the free drug, but acetazolamide, an inhibitor carbonic anhydrase IX, significantly reduced GBM cell viability in 3D spheroids. Results from these studies show that high loading of drugs into telodendrimer micelles requires a physical fit between the biologically active agent and telodendrimer nanocarrier, and points toward new possibilities for incorporation of chemotherapeutic and other agents to enhance their effectiveness.