Microporous capsules (MCs) such as polymerosomes [1,2] feature attractive properties for potential applications in materials development, optics, electronics, and delivery. [3,4] Colloidosomes are a related class of MCs whose shells consists of densely packed colloidal particles. These systems feature useful attributes including enhanced mechanical stability and controlled pore-size distribution, [5] as well as the optical, fluorescent, and magnetic properties of their precursor particles.Colloidosomes feature an identical solvent inside and out (typically water), and have been generally synthesized using micrometer-or submicrometer-sized particles. [4a,6] However, the formation of stable colloidosomes using nanoparticles (NPs) <20 nm in diameter remains a challenge. [7] The competition between the interfacial energy and the spatial fluctuation of the NPs resulting from thermal energy causes instability of the emulsions. Recent approaches to fabricate colloidosomes have included different types of NPs, as well as the use of assembly strategies. [8,9] For example, Duan et al. have used agarose to gelate water at the water-oil interface and transferred the resultant MCs into water to create stable colloidosomes. [9] In recent studies, we and others have developed various crosslinking reactions between NPs at water-oil droplet interfaces. [10] However, to the best of our knowledge there are no reports of successful transfer of these crosslinked droplets into water to synthesize colloidosomes.Herein, we report the fabrication of stable magnetic colloidosomes by crosslinking NPs at a water-oil interface using click chemistry under ambient conditions. In this strategy, alkyne-and azide-functionalized Fe 3 O 4 NPs were coassembled at the interface and covalently linked using a Cu(I)-catalyzed Huisgen click reaction. [11,12] There are two major advantages for this interfacial crosslinking method. First, click chemistry involving alkyne and azide functional groups is highly selective and essentially inert to the many functional groups and environmental conditions (e.g., pH and solvent). [13][14][15][16][17] Second, this methodology provides dense packing of NPs on the colloidosome shell, resulting in high stability of the colloidosomes.The alkyne (IO-1) and azide (IO-2) NPs used in this study were formed by place-exchange of oleic acid from Fe 3 O 4 NPs that were 11.3 AE 2 nm in diameter (see Supporting Information, Figure S1). These NPs were dissolved in an equimolar ratio in oil (a mixture of toluene and methylene chloride with a 7:1 ratio), and an aqueous solution of the Cu(I) catalyst (a mixture of CuSO 4 and sodium L-ascorbate) was added with vigorous shaking for %30 s (Scheme 1). The colloidosomes formed by this technique were 49 AE 15 mm (Figure 1a) in diameter, and required a crosslinking time of 30 min with a catalyst concentration of 0.8 mM to form stable assemblies. The catalyst concentration had little effect on the shape and size of the colloidosomes (see Supporting Information, Figure S2), however onl...

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Nanoimprint lithography (NIL) is viewed as an alternative nanopatterning technique to traditional photolithography, allowing micrometer-scale and sub-hundred-nanometer resolution as well as three-dimensional structure fabrication. In this Research News article we highlight current activities towards the use of NIL in patterning active or functional materials, and the application of NIL in patterning materials that present both chemistry and structure/topography in the patterned structures, which provide scaffolds for subsequent manipulation. We discuss and give examples of the various materials and chemistries that have been used to create functional patterns and their implication in various fields as electronic and magnetic devices, optically relevant structures, biologically important surfaces, and 3D particles.

ZnO-polypropylene nanocomposites (nano-PP) were prepared using nanoparticles of ZnO stabilized by soluble starch (nano-ZnO) as filler in PP by the melt mixing process. X-ray diffraction (XRD) and other spectroscopic analysis—ultraviolet–visible (UV–vis), Fourier transform infrared (FTIR) and photoluminescence—revealed the presence and characteristics of nano-ZnO in the composites. The presence of ZnO imparts whiteness, while starch increased the yellowing of polymers. The nanocomposites were analyzed for changes in optical, mechanical, electrical and rheological properties, as influenced by the increasing concentration of nano-ZnO. The mechanical properties were marginally increased and the dielectric strength of the nano-PP increased to a notable level. By monitoring the evolution of the carbonyl absorption bands from FTIR analysis, the efficacy of nano-ZnO in the reduction of photo-degradation due to UV irradiation was demonstrated. The excellent antibacterial activity exhibited by nano-ZnO impregnated PP against two human pathogenic bacteria, Staphylococcus aureus and Klebsiella pneumoniae, makes it a suitable candidate for food packaging applications.

Materials and Methods:Swallowtail-substituted carboxylate PPE (Sw-CO 2 ) was synthesized according to published procedure.1 Fluorescence intensity changes at 465 nm were recorded in 96-well plates (300 µL Whatman ® Glass Bottom microplate) on a Molecular Devices SpectraMax M5 micro plate reader with an excitation wavelength of 405 nm. Phosphate buffer (PB), phosphate buffered saline (PBS), piperazine-1,4-bis(2-ethanesulfonic acid) (PIPES), N-2-hydroxyethylpiperazine-N ' -2-ethanesulfonic acid (HEPES), and tris(hydroxymethyl)aminomethane hydrochloride (Tris-HCl) were purchased from Sigma-Aldrich. The buffers were diluted to a concentration of 5 mM and a pH of 7.2 with DI H 2 O. To calculate log P, computational program Maestro 8.0 was used.

A nanoimprint-lithography-based fabrication method to generate stable protein films is described. The process is environmentally friendly and generalizable with respect to the protein building blocks. These non-fouling surfaces are readily patternable, incorporate intrinsic protein charge into the film, and able to control cellular adhesion.

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