Janus micellessasymmetric star block copolymers resulting from cross-linking of the polybutadiene middle blocks of polystyrene-block-polybutadiene-block-poly(methyl methacrylate) triblock copolymerss and the corresponding non-cross-linked ABC triblock copolymer precursors form monolayers on a water surface. Analysis of the lateral pressure/area isotherms and scanning force microscopy images of monolayers spread from dilute chloroform solutions reveal a lateral structure: In monolayers of both polymers, one observes elevated nanometer-sized domains separated by flat regions. However, the monolayers made from the two copolymers differ in morphology and size of the observed domains. Janus micelle monolayers are predominantly composed of arrays of circular domains with height of 16-18 nm and diameter of 70-80 nm, while the monolayers of the precursor triblock copolymer are mainly composed of significantly smaller elongated domains of approximately 3 nm height, 40 nm width, and nonuniform length. The formation of domains and the shape of the lateral pressure/area isotherms are in accordance with the assumption that the poly(methyl methacrylate) chains spread out on the water surface, while the hydrophobic polystyrene and polybutadiene chains dewet from the water surface. Differences in domain morphology are probably due to the different chain architectures of the two polymers but may as well be influenced by the preaggregation in the spreading solvent.

Polymer membranes with closely packed two-dimensionally arranged pores have been prepared at the water surface using monolayers of silica colloids as templates. The resulting porous membranes were used as templates for the preparation of gold rings via filling of pores with a solution of gold precursor followed by calcinations. The size of the resulting rings can be easily controlled by tuning the pore size of the templating membrane.

Forty-nanometer-thin free-standing membranes with 55-nm-wide pores have been prepared via Langmuir-Blodgett transfer. Hydrophobized silica colloids and polyisoprenes with quaternary ammonium headgroups were jointly spread onto a water surface to form a hybrid monolayer in which two-dimensional ordered domains of particles are embedded in a polymer monolayer matrix. Photochemical cross-linking of the polyisoprene, followed by transfer to gold grids with 100-µm wide openings yielded free-standing hybrid membranes. Removal of the colloids gives rise to a free-standing membrane with pores of uniform size. These porous membranes might find application as improved filtration media or as masks or molds for surface patterning and nanostructure fabrication.

We have synthesized polyethoxysiloxanes starting from the AB3‐type monomers triethoxysilanol and acetoxytriethoxysilane. The polymers are liquid and soluble in organic solvents. 29Si NMR spectroscopy and MALDI‐ToF mass spectrometry analyses show that the polymers have a hyperbranched structure with additional internal cyclization. 29Si NMR spectroscopy indicates that the polymer synthesized from acetoxytriethoxysilane is less branched than the polymer synthesized from triethoxysilanol. Analysis of the molar mass and mass distribution of the polymers via size exclusion chromatography (calibrated via MALDI‐ToF MS and viscosimetry) yields a molar mass of Mn ≈ 2 kg · mol−1 and Mw ≈ 8 kg · mol−1 for polymers synthesized from triethoxysilanol. The molar mass of the polymers synthesized from acetoxytriethoxysilane can be controlled by variation of the polymerization time in the range of Mn ≈ 1.8–12 kg · mol−1 and Mw ≈ 2.1–2 200 kg · mol−1. Photograph of a vial containing polyethoxysiloxane obtained from triethoxysilanol and a schematic drawing of the proposed molecular structure of the polymer.magnified imagePhotograph of a vial containing polyethoxysiloxane obtained from triethoxysilanol and a schematic drawing of the proposed molecular structure of the polymer.