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A small/wide-angle X-ray scattering and grazing incidence diffraction study of comb-shaped supramolecules of conjugated poly(2,5-pyridinediyl), acid dopant and hydrogen bonded amphiphilic side chains is reported. In solution, polymers are dissolved rodlike particles. When the side-chains are introduced, polymers self-assemble in hierarchic liquid crystals (LC). Diffraction patterns of aligned LC show h00, 020, and 004 reflections, and additional small-angle reflections along the polymer axis. A triangular correlation function indicating a very large correlation length is seen along the smectic axis. An aligned solid structure can be formed by cleaving side chains from the aligned LC.

Applying Scanning Probe Microscopy (SPM) methods to determine structural details of biomolecules (e.g. proteins) is one of the key trends in nanotechnology. Here we present the analysis of a Langmuir-Blodgett film of hydrofobin HFBI. The statistical analysis is based on an accurate procedure of data detrending to study the quasi-crystalline clusters of the HFBI layer. A statistical improvement method of signal to noise ratio was used. It relies on the variation of the crystallographic lattice superimposed on a quasi-periodical data set. The procedure produces optimal values of crystallographic periods and orientations of the symmetry axes. This information is used for selecting coherent data sets within a crystallographic cluster. Superposition of cells from the same cluster and calculation of an average periodical structure improves the signal to noise ratio, which leads from nano to subnano resolution of the protein structure. The number of superimposed cells N defines the resolution gain factor N1/2. In the case of hydrofobin, the value of N lies in the range of 25-100. This allows for the determination of fine structural details of HFBI. Average structures obtained from different domains of the protein layer also show a high degree of reproducibility.

We report on the phase behavior of poly(9,9-dihexylfluorene) (PF6), poly(9,9-diheptylfluorene) (PF7), poly(9,9-dioctylfluorene) (PF8), poly(9,9-dinonylfluorene) (PF9), and poly(9,9-didecylfluorene) (PF10) in methylcyclohexane (MCH). After a heating−cooling cycle, in the 10−50 mg/mL concentration range, PF6/MCH, PF7/MCH, PF8/MCH, and PF9/MCH systems were found to be gel-like, while PF10/MCH appears less viscous. PF6/MCH, PF7/MCH, PF8/MCH, and PF9/MCH form large (10−100 nm) sheetlike assemblies (thickness of 2−3 nm). The larger length scale structures of these sheets show an odd−even dependence on the side chain (spacer) length: the PF6 and PF8 sheets are broader and thinner, whereas PF7 and PF9 sheets are thicker with a putative double layer structure. PF10 does not follow this sequence, and only part of the polymer is assembled into a sheetlike structure, the rest remaining dissolved at the molecular level. PF8/MCH and PF9/MCH mixtures also have lower length scale crystalline structures with an internal period corresponding to the periodicity observed in the solid-state β phase of PF8. Vestiges of crystalline domains are found for PF6 and PF7 but not for PF10. PF7/MCH, PF8/MCH, and PF9/MCH systems contain the conformational isomer Cβ, of those chains observed in the β phase, while this is not observed with other polymer/MCH systems.

It was demonstrated that polymeric supramolecular nanostructures with several length scales allow straightforward tailoring of hierarchical order-disorder and order-order transitions and the concurrent switching of functional properties. Poly(4-vinyl pyridine) (P4VP) was stoichiometrically protonated with methane sulfonic acid (MSA) to form P4VP(MSA) 1.0 , which was then hydrogen-bonded to pentadecylphenol. Microphase separation, re-entrant closed-loop macrophase separation, and high-temperature macrophase separation were observed. When MSA and pentadecylphenol were complexed to the P4VP block of a microphase-separated diblock copolymer poly[styrene- block -(4-vinyl pyridine)], self-organized structures-in-structures were obtained whose hierarchical phase transitions can be controlled systematically. This microstructural control on two different length scales (in the present case, at 48 and 350 angstroms) was then used to introduce temperature-dependent transitions in electrical conductivity.

Application to rod-likepolymers (such as p-conjugated electroactive polymers)could lead to possible new applications, but is not straight-forward because such polymers tend to be infusible andpoorly soluble. For polymers containing rod-like moieties,self-organization has been achieved based on di-block co-polymers with flexible blocks