Emulsions are important in numerous fields, including cosmetics, coatings, and biomedical applications. A subset of these structures, oil-in-oil emulsions, are especially intriguing for water sensitive reactions such as polymerizations and catalysis. Widespread use and application of oil-in-oil emulsions is currently limited by the lack of facile and simple methods for preparing suitable surfactants. Herein, we report the ready preparation of oil-in-oil emulsions using 2D nanomaterials as surfactants at the interface of polar and nonpolar organic solvents. Both the edges and basal plane of graphene oxide nanosheets were functionalized with primary alkyl amines and we demonstrated that the length of the alkyl chain dictates the continuous phase of the oil-in-oil emulsions (i.e., nonpolar-in-polar or polar-in-nonpolar). The prepared emulsions are stable at least 5 weeks and we demonstrate they can be used to compartmentalize reagents such that reaction occurs only upon physical agitation. The simplicity and scalability of these oil-in-oil emulsions render them ideal for applications impossible with traditional oil-in-water emulsions, and provide a new interfacial area to explore and exploit.

Janus particles have recently garnered significant attention for their distinct properties compared to particles that are homogeneously functionalized. Moreover, high aspect ratio Janus particles that are rod-like or planar (i.e., nanosheets) are especially intriguing considering their interfacial properties as well as their ability to assemble into higher order and hybrid structures. To date, major challenges facing the exploration and utilization of 2D Janus particles are scalability of synthesis, characterization of tailored chemical functionalization, and ability to introduce a diverse set of functionalities. Herein, a facile method to access Janus 2D graphene oxide (GO) nanosheets by combining a Pickering-type emulsion and grafting-from polymerization via ATRP is reported. Janus GO nanosheets bearing PMMA on one face as well as the symmetrically functionalized analogue are prepared, and the chemical, thermal, structural, surface, and interfacial properties of these materials are characterized. Time-of-flight secondary ion mass spectrometry coupled with Langmuir–Blodgett films is shown to be an ideal route to conclusively establish asymmetric functionalization of 2D materials. This work not only provides a facile route for the preparation of Janus nanosheets but also demonstrates the direct visualization of polymer grown from the surface of GO.Keywords: asymmetric functionalization; grafting-from; graphene oxide; Janus particles; ToF-SIMS;

The atomic composition and chemical structure of polymers is fundamental to dictating properties and applications. While much work has addressed controlling pendant group functionalities and polymer molecular weight, much less work has focused on novel polymer backbone chemistries. Herein we report experimental and computational investigations of the polymerization of triisopropyl silyl (TIPS) ketene, and detail products formed. TIPS ketene reacts with an alkoxide initiator to give an enolate intermediate that propagates through either the carbon or oxygen atom, giving multiple functional groups in the resulting polymer backbone. This work indicates that silyl ketenes are suitable monomers for chain growth polymerizations, and that they can polymerize through both the CC and CO to prepare multiple polymer functionalities from a single monomer.

The evergrowing amount of data created and collected is met with the increased need to store this data. In compliment to improving data storage capabilities using engineering controls such as decreased pixel size (i.e., Blu-ray) or 3-D pixels (i.e., voxels), chemistry-based approaches are required to move beyond current limitations and meet our future needs. Herein, we present a new methodology to optically store data in a quaternary code of 0, 1, 2, 3 in a commodity polymer containing a low loading of two small molecules, and using heat and UV light to write, and read fluorescence output. The as-prepared film is non-fluorescent (0), and can be written through a wooden or metal mask with thermal treatment (1), light treatment (2), or both (3), giving three different colours of fluorescence under UV irradiation. The flexible polymer film remains colourless and transparent under ambient light after patterning, retains the stored data after exfoliation with sandpaper, and can be removed from the substrate and mechanically deformed without detriment to the pattern. This straightforward and scalable system demonstrates the use of simple and robust chemical reactions to improve data storage capabilities and has the potential to exponentially increase information density.

Graphene oxide (GO) is selectively functionalized on one face to prepare Janus platelets which are characterized by various spectroscopic and microscopic techniques. With this methodology, Janus GO platelets can be prepared without the use of a solid substrate and the two platelet faces can be orthogonally modified in a one-pot reaction.

Micron-sized hollow capsules composed of graphene oxide and small molecule cross-linker are prepared and isolated. These capsules are thoroughly characterized using various spectroscopic and microscopic techniques. The cross-linked and non-cross-linked microcapsules show distinct release profiles from each other. Moreover, the microcapsules can be loaded with gold nanoparticles, suggesting these structures are useful in encapsulation technologies.

•Polymer composite can be patterned with fluorescence signature by simple irradiation with UV light.•After washing patterned polymer with organic solvent a colored pattern remains.•UV light is used to control solubility of phthalocyanine within a polymer matrix.Polymer composites containing stimuli responsive small molecules have been explored for various applications, including patterning and data storage. Phthalocyanines (Pc) have been widely synthesized and used as dyes, catalysts, and optical limiting materials, as well as active components in modern organic electronic devices. The solubility of Pcs and miscibility with a polymer matrix require the use of covalently attached alkyl side chains that rarely serve any other purpose than solubility. Herein we report a polymer composite with a novel cobalt (II) Pc dye with alkyl chains connected through a photolabile linker. The materials are synthesized using standard reactions and characterized by FTIR, MALDI, and absorption and emission spectroscopies. Upon UV irradiation in solution or in the polymer films, the alkyl groups are cleaved rendering the Pc core insoluble and turning on fluorescence of the small molecule byproduct. This observation is in direct contrast to treatment of similar Pc molecules that lack the photoresponsive group. PMMA and PDMS films are patterned with resolution down to 250 μm using only 0.1 wt% of our tailored Pc molecule. This work presents a fundamental method for patterning in polymer films by tuning the solubility, color, and fluorescence of a Pc based system and could ultimately be used for sensing, data storage, or pigmentation.

The evergrowing amount of data created and collected is met with the increased need to store this data. In compliment to improving data storage capabilities using engineering controls such as decreased pixel size (i.e., Blu-ray) or 3-D pixels (i.e., voxels), chemistry-based approaches are required to move beyond current limitations and meet our future needs. Herein, we present a new methodology to optically store data in a quaternary code of 0, 1, 2, 3 in a commodity polymer containing a low loading of two small molecules, and using heat and UV light to write, and read fluorescence output. The as-prepared film is non-fluorescent (0), and can be written through a wooden or metal mask with thermal treatment (1), light treatment (2), or both (3), giving three different colours of fluorescence under UV irradiation. The flexible polymer film remains colourless and transparent under ambient light after patterning, retains the stored data after exfoliation with sandpaper, and can be removed from the substrate and mechanically deformed without detriment to the pattern. This straightforward and scalable system demonstrates the use of simple and robust chemical reactions to improve data storage capabilities and has the potential to exponentially increase information density.

Graphene oxide (GO) is selectively functionalized on one face to prepare Janus platelets which are characterized by various spectroscopic and microscopic techniques. With this methodology, Janus GO platelets can be prepared without the use of a solid substrate and the two platelet faces can be orthogonally modified in a one-pot reaction.