Inorganic–organic mesophase materials provide a wide range of tunable properties, which are often highly dependent on their nano‐, micro‐, or meso‐scale compositions and structures. Among these are macroscopic orientational order and corresponding anisotropic material properties, the adjustability of which are difficult to achieve. This is due to the complicated transient and coupled transport, chemical reaction, and surface processes that occur during material syntheses. By understanding such processes, general criteria are established and used to prepare diverse mesostructured materials with highly aligned channels with uniform nanometer dimensions and controllable directionalities over macroscopic dimensions and thicknesses. This is achieved by using a micropatterned semipermeable poly(dimethylsiloxane) stamp to manage the rates, directions, and surfaces at which self‐assembling phases nucleate and the directions that they grow. This enables mesostructured surfactant‐directed silica and titania composites, including with functional guest species, and mesoporous carbons to be prepared with high degrees of hexagonal order, as well as controllable orthogonal macroscopic orientational order. The resulting materials exhibit novel anisotropic properties, as demonstrated by the example of direction‐dependent photocurrent generation, and are promising for enhancing the functionality of inorganic–organic nanocomposite materials in separations, catalysis, and energy conversion applications.

A combination of nonionic, cationic, and zwitterionic surfactants is shown both to stabilize the transmembrane protein proteorhodopsin, as well as to direct coassembly into robust transparent mesostructured silica-surfactant films containing high loadings of functionally active protein guests. Proteorhodopsin is a transmembrane protein that exhibits light-activated H+ transport properties, the photocycle kinetics of which are quantified by time-resolved UV-visible spectroscopy and demonstrated to be similar to proteorhodopsin in the abiotic mesostructured films compared to native-like lipids. The surfactants mediate the pK(a) of a key ion-channel residue, leading to an expanded pH functional range for proteorhodopsin in mesostructured silica-surfactant host materials. Small-angle X-ray diffraction results for 100-mu m films show high extents of mesoscale order with protein loadings up to 25 wt % and wormlike mesostructural order for 44 wt % proteorhodopsin. Solid-state H-1, C-13, and Si-29 NMR analyses provide atomic-scale insights into the compositions and interactions at the mesochannel surfaces, which account for the structure-directing roles of surfactant species. Nanoindentation measurements reveal the mechanical robustness of the films, which interestingly increases with proteorhodopsin loading for the compositions examined. Heat treatment analyses show improved thermal stability for proteorhodopsin to 110( degrees)C within mesostructurally ordered films. The results establish closely correlated relationships between the compositions, nano- and mesoscale structures, photocycle kinetics, and macroscopic mechanical properties and thermal stabilities of the silica-surfactant- proteorhodopsin films, providing key biomimetic design criteria.

The functional properties of proteorhodopsin (PR) have been found to be strongly modulated by oligomeric dis-tributions and lipid membrane mimetics. This study aims to distinguish and explain their effects by investigating how oligomer formation impacts PR's function of proton transport in lipid-based membrane mimetic environments. We find that PR forms sta-ble hexamers and pentamers in both E. coli membranes and synthetic liposomes. Compared with the monomers, the photocycle kinetics of PR oligomers is -2 and -4.5 times slower for transitions between the K and M and the M and N photointermediates, respectively, indicating that oligomerization significantly slows PR's rate of proton transport in liposomes. In contrast, the apparent pKa of the key proton acceptor residue D97 (pKaD97) of liposome-embedded PR persists at 6.2-6.6, regardless of cross-protomer modulation of D97, suggesting that the liposome environment helps maintain PR's functional activity at neutral pH. By comparison, when extracted directly from E. coli membranes into styrene-maleic acid lipid particles, the pKaD97 of mono-mer-enriched E50Q PR drastically increases to 8.9, implying that there is a very low active PR population at neutral pH to engage in PR's photocycle. These findings demonstrate that oligomerization impacts PR's photocycle kinetics, while lipid-based mem-brane mimetics strongly affect PR's active population via different mechanisms.