The interfacial assembly of graphene oxide (GO) at the water/oil interface and its kinetics were systematically studied. GO nanosheets were found to segregate to the water/oil interface and interact with quaternized block copolymer chains by the peripheral carboxyl groups on the GO. If the interfacial area is decreased, then GO, assembled at and confined to the interface, jams and then buckles. An analysis of the kinetics of the assembly processes leads to the conclusion that the diffusion of GO to the interface is the rate-determining step. The morphology of the jammed GO film was investigated, and TEM images show that GO sheets form a mosaic or tile across the whole oil/water interface.

Through pH-tuning of electrostatic interactions between polymer ligands and nanoparticles at structured-liquid interfaces, liquid droplets can be directed between a jammed nonequilibrium state and a dynamic reconfigurable state. The nanoparticle-surfactant dynamics highly depend on the pH, so that the liquids can be structured using an external field and under variation of pH, or alternatively being realized by remote photo-triggering.

Using the interfacial jamming of cellulose nanocrystal (CNC) surfactants, a new concept, termed all-liquid molding, is introduced to produce all-liquid objects that retain the shape and details of the mold with high fidelity, yet remain all liquid and are responsive to external stimuli. This simple process, where the viscosity of the CNC dispersion can range from that of water to a crosslinked gel, opens tremendous opportunities for encapsulation, delivery systems, and unique microfluidic devices. The process described is generally applicable to any functionalized nanoparticles dispersed in one liquid and polymer ligands having complementary functionality dissolved in a second immiscible liquid. Such sculpted liquids retain all the characteristics of the liquids but retain shape indefinitely, very much like a solid, and provide a new platform for next-generation soft materials.

A simple method was developed to realize a self-assembled block copolymer (BCP) lamellar microdomain morphology with a full pitch of 5.4 nm through an acid hydrolysis of poly(solketal methacrylate-b-styrene) (PSM-b-PS). The acid hydrolysis transforms PSM-b-PS, having two hydrophobic blocks, into poly(glycerol monomethacrylate-b-styrene) (PGM-b-PS), having one hydrophilic and one hydrophobic block. This transformation markedly increases the segmental interaction parameter such that a phase-mixed PSM-b-PS can be transformed in the solid state into a microphase-separated BCP without the use of any additives. Correlation hole scattering of the PSM-b-PS in the phase mixed state yields a segmental interaction parameter (χ) given by χ = 0.0196 + 4.694/ T, where T is the absolute temperature. With the symmetric BCPs used in this study, the ordered lamellar microdomain pitch was determined by small-angle X-ray scattering (SAXS) as a function of the degree of polymerization (16 ≤ N ≤ 1246). For the lamellar microdomains of PGM-b-PS, the scattering profiles show many higher order reflections with an increase in the domain spacing (L 0 ). The lowest molar mass sample (M n = 2200 g/mol, N = 16) had sub-3 nm microdomains after conversion to PGMb-PS.