In biology, lipids are well known for their ability to assemble into spherical vesicles. Proteins, in particular virus capsids, can also form regular vesicle-like structures, where the precise folding and stable conformations of many identical subunits directs their self-assembly. Functionality present on these subunits also controls their disassembly within the cellular environment, for example, in response to a pH change. Here, we report the preparation of diblock copolypeptides that self-assemble into spherical vesicular assemblies whose size and structure are dictated primarily by the ordered conformations of the polymer segments, in a manner similar to viral capsid assembly. Furthermore, functionality was incorporated into these molecules to render them susceptible to environmental stimuli, which is desirable for drug-delivery applications. The control of assembly and function exhibited in these systems is a significant advance towards the synthesis of materials that can mimic the precise three-dimensional assembly found in proteins.

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Micropatterning has applications in a wide range of areas. In contrast to the technological world, where micropatterns are produced lithographically, biological systems provide numerous examples of the formation of biominerals with intricate surface patterns and architectures, which are involved in a variety of biological functions, such as protection and light harvesting. 1 Biominerals are formed through an intimate association between inorganic and organic materials, where amphiphile-derived vesicles are often involved. Vesicles formed on cell membrane walls provide templates for inorganic material deposition. In addition, vesicle fusion, fission, collapse, and inorganic material deposition often occur synergistically, resulting in the formation of complex patterns over multiple length scales. 2 Vesicle templating has been used to create materials with complex structures. For example, bowl-shaped depressions have been produced on the surfaces of aluminophosphate spheres using alkylamines as surfactants at 180°C. 3 Vesicular silica structures have been synthesized using a vesicle-assisted process. [4][5][6] In contrast to the previous efforts on the vesicle-templated synthesis of spherical particles with intriguing surface features and internal mesostructures, here we report an approach for generating surface patterns of microscale silica features up to areas of 10 mm 2 using vesicle arrays as templates at room temperature. The morphologies of silica features, including convex protrusions, concave depressions, and their hierarchical combinations, are controlled synthetically. It is further demonstrated that these surface patterns can function as arrays of microlenses that are capable of producing numerous images from a common object.Our vesicle-templating approach makes use of a Pluronic triblock copolymer, L31. 7 The preparation starts with mixing tetraethyl orthosilicate (TEOS), ethanol, and an aqueous HCl solution of pH ∼2. TEOS is prehydrolyzed by stirring at 60°C for 4 h, and then L31 and dimethylformamide (DMF) are added, giving a molar composition of 1 TEOS:4.0 C 2 H 5 OH:4.0 H 2 O:0.056 L31:0.61 DMF. After the mixture is further stirred vigorously for ∼1 min, an appropriate amount is transferred into an open cylindrical well of 7 mm in diameter and 8 mm in depth. The mixture is gelled and dried in air for 2-4 days, during which a cylindrical transparent monolith forms with surface patterns present on its top surface. The monolith has a diameter of ∼5 mm, and its height varies from 2 to 5 mm, depending on the amount of the solution transferred into the well.Scanning electron microscopy (SEM) imaging shows that the entire top surfaces of as-prepared monoliths are covered with remarkable patterns of silica features arranged in a roughly hexagonal symmetry ( Figure 1a). SEM imaging on tilted monoliths indicates that the silica features are convex protrusions with smooth surfaces (Figure 1b). They are stable under the electron beam of 2-5 keV. Their diameters are relatively uniform, in the range of 10-40 µ...

A mineral carbonation method for using anthropogenic carbon dioxide emissions is discussed. In this method, steel manufacturing slags are carbonated with gaseous carbon dioxide at atmospheric pressure and temperature using an aqueous ammonium chloride solution. This lixiviant extracts calcium selectively from the slag material, after which the dissolved calcium is precipitated as calcium carbonate. A flue gas stream can be used as a CO2 source without pre-separation. The reactions occur pseudo-catalytically in one vessel, resulting in considerable savings regarding process capital costs and reagent usage compared to a previously developed two-step carbonation method (Slag2PCC). The one-step method uses steel slag more efficiently, potentially reducing the amount of landfilled slag while capturing significantly more carbon dioxide in the same amount of slag. The two-step method produces >95% pure calcium carbonate, which can be used, e.g., in papermaking, while the one-step method is capable of manufacturing 60–75% pure carbonates for reuse at the steel plant, thus decreasing the need of virgin raw materials, such as limestone. Direct recycling would also reduce the transportation and processing requirements, resulting in a better overall process economy.

PubHc repoiting burden for this eolediori of kiformatlan is estimated to average 1 hour per response, Including the time tar ieviewln$ the data needed, and completing and reviewing this colection of Information. Send comments regarding tNs burden estimate V an),.n. The objective of this proposal was to develop novel materials and devices with dynamically variable refractive index properties, based on new hierarchically ordered composites and porous solids. The dominant innovation is the development of biologically inspired selfassembling inorganic/organic materials, whose versatile response properties can be designed and controlled, according to a variety of specific conditions, field stimuli, and performance criteria. Specifically, it was our goal to create mesostructured composite lens materials with large and reversible changes in their refractive indices (AM values of 0.5-1.0). This was to be demonstrated, by incorporating components with strong charge-transfer responses to applied optical (near-UV and near-IR) and electrical fields. Modest refractive index changes were obtained in thin film preparations of hybrid mesostructured materials (A« values of 0.1-0.27). However, we were unable to achieve AM values close to or above 1.0 for isotropic light. List of Figures Figure 1: A 2.5-cm diameter x 3-mm thick mesostructurally ordered transparent silica/block copolymer monolith prepared with 60 wt% EO106-PO70-EO106. TEM and XRD diffraction results demonstrate the high degrees of mesoscopic and macroscopic orientational ordering in the sample.''^" Figure 2:Organic dye species, such as spiropyrans, porphyrins, near-IR chromophores, or surfactant-passi-vated nanocrystals (also shown), are preferentially incorporated into the hydrophobic regions of the silica/PEO-PPO-PEO composites. These species can be incorporated with higher concentrations and significantly greater homogeneities, as the weight percent of the EO106PO70EO106 (F127) block copolymer species increases. Figure 3:Optical wave guides hierarchically patterned on both the mesoscopic and photonic length scales by using block-copolymer self-assembly, latex-sphere templating and soft lithography. SummaryThe objective of this proposal was to develop novel materials and devices with dynamically variable refractive index properties, based on new hierarchically ordered composites and porous solids. The dominant innovation is the development of biologically inspired self-assembling inorganic/organic materials, whose versatile response properties can be designed and controlled, according to a variety of specific conditions, field stimuli, and performance criteria Specifically, it was our goal to create mesostructured composite lens materials with large and reversible changes in their refractive indices (A« values of 0.5-1.0). This was to be demonstrated, by incorporating components with strong charge-transfer responses to applied optical (near-UV and near-IR) and electrical fields. Modest refractive index changes were obtained in thin film preparations of hyb...