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We developed nanostructured gradient wrinkle surfaces to establish a one-step screening process towards optimal assembly of soft and hard colloidal particles (microgel systems and silica particles). Thereby, we simplify studies on the influence of wrinkle dimensions (wavelength, amplitude) on particle properties and their alignment. In a combinatorial experiment, we optimize particle assembly regarding the ratio of particle diameter vs. wrinkle wavelength and packing density and point out differences between soft and hard particles. The preparation of wrinkle gradients in oxidized top layers on elastic poly(dimethylsiloxane) (PDMS) substrates is based on a controlled wrinkling approach. Partial shielding of the substrate during plasma oxidation is crucial to obtain two-dimensional gradients with amplitudes ranging from 7 to 230 nm and wavelengths between 250 and 900 nm.

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Catalytic processes for biomass conversion are currently gaining renewed importance as potential alternatives to petrochemical counterparts. The metal-catalyzed hydrogenolysis of cellulose and sugars presents an interesting approach for the synthesis of fuels and polyols. This chapter covers the historical development of the hydrogenolysis of cellulose, discusses the mechanistic understanding of the reaction and highlights recent advances concerning catalyst development and process optimization. More specifically, the hydrolysis of cellulose and the degradation of glucose in aqueous medium as well as the role of the hydrogenation/hydrogenolysis catalyst are discussed to provide an insight into factors governing product distribution. Studies focusing on cellobiose as a model compound of cellulose are covered. Finally, an overview of recently developed catalyst systems based on noble and base metals in neutral and acidic aqueous medium is given. These studies confirm that the hydrogenolysis of cellulose is a highly versatile reaction allowing for optimization of the product distribution either towards hexitols or towards shorter-chain polyols, such as ethylene and propylene glycol.