Photoswitchable compounds are promising materials for solar‐thermal energy conversion and storage. In particular, photoresponsive azobenzene‐containing compounds are proposed as materials for solar‐thermal fuels. In this feature article, solar‐thermal fuels based on azobenzene‐containing polymers (azopolymers) are reviewed. The mechanism of azopolymer‐based solar‐thermal fuels is introduced, and computer simulations and experimental results on azopolymer‐based solar‐thermal fuels are highlighted. Different types of azopolymers such as linear azopolymers, 2D azopolymers, and conjugated azopolymers are addressed. The advantages and limitations of these azopolymers for solar‐thermal energy conversion and storage, along with the remaining challenges of azopolymer‐based solar‐thermal fuels, are discussed.

Using in situ nanodielectric spectroscopy we demonstrate that the imbibition kinetics of cis-1,4polyisoprene in native alumina nanopores proceeds in two time regimes both with higher effective viscosity than bulk. This finding is discussed by a microscopic picture that considers the competition from an increasing number of chains entering the pores and a decreasing number of fluctuating chain ends. The latter is a direct manifestation of increasing adsorption sites during flow. At the same time, the longest normal mode is somewhat longer than in bulk. This could reflect an increasing density of topological constraints of chains entering the pores with the longer loops formed by other chains.

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Protein crystallization is a crucial step in the study of protein structure and function, [1] as well as in biosensing. [2][3][4] In many cases, it proceeds under ill-controlled conditions, which make it difficult to predict the outcome or feasibility. On the other hand, controlled two-dimensional (2D) protein recrystallization has been mainly accomplished through metal-ion coordination to accessible histidine residues [5] or specific interactions with high-affinity ligands.[6] Both approaches, however, involve knowledge of the protein structure and, in some cases, protein engineering. In this work, we show that control of the morphology of a 2D wild-type protein crystal is possible by using a chemical nanotuner as a substrate. In this way, nonspecific substrate-protein interactions can be finely modulated to select the self-assembly pathway to the corresponding protein crystal. Our model system consists of a bacterial S-layer, a two-dimensional (glyco)protein crystal located in the cell wall of many prokaryotic organisms.[7] The S-layers act as selective, protective barriers that mediate cell development.[8] The chemical nanotuner is a set of selfassembled monolayers (SAMs) of dialkyldisulfide derivatives with the formula CH 3 (CH 2 ) 11+m SS(CH 2 ) 11 OH, in which m is the chain-length difference in methylene units between the methyl-and the hydroxy-terminated branches.[9] The resulting surface is composed of OH-and CH 3 -terminated thiolates in a stand-up conformation with a defined chemical functionality ratio of 50 %. These SAMs contain submolecular protrusions whose nature is controlled by the m value: m < 0 indicates that the protruding chains are OH terminated, whereas m > 0 denotes that the surface protrusions are methyl functionalized (Figure 1). The variation in the m value determines the protein-recrystallization route.