Elastomeric Suspended Membranes Generated via Langmuir−Blodgett Transfer

Abstract

Elastomeric freely suspended membranes have been prepared via Langmuir−Blodgett transfer of cross-linked monolayers of polyisoprenes with anthracene side chains and sulfonate headgroups. The polymers, which have a chain length of approximately 540 repeat units and on average 8 anthracene side chains per polymer molecule, were spread at an air−water interface from chloroform/ethanol solutions and laterally compressed to an average area per molecule of 200 Å2. These monolayers were cross-linked via irradiation with UV light of wavelength 305−420 nm and then transferred to a brass plate with a circular hole of 0.4 mm diameter. The approximately 40 nm thick cross-linked monolayers completely covered the hole. It was possible to elastically deform the resulting suspended membrane by applying an overpressure from one side.

Freestanding Nanosheets from Crosslinked Biphenyl Self‐Assembled Monolayers

“…[1][2][3][4][5][6] To date, most work has focused on the synthesis and self-assembly of nanocrystals that are stabilized with alkane ligands (CH 3 (CH 2 ) n R, R = SH, NH 2 , PO, etc.). [3,7,8] Such NCs can be made at fairly high quality (narrow size distribution, preferred shapes such as rod, cube, etc., and large production). These NCs are hydrophobic, and their self-assembly is limited to organic solvents.…”

“…[1] To date, nanosized objects, such as nanospheres, [2] nanowires, [3] or nanobelts [4] have been prepared from various materials, such as metals, ceramics, or organic polymers. Carbon nanotubes are another well-known example of supramolecular objects with one mesoscopically extended dimension and two others confined to the nanometer length scale.[5] Two-dimensionally extended nanomaterials have been prepared, e.g., from polyelectrolyte multilayers, with a thickness between 10 and 15 nm.[6] Similar freestanding polymeric membranes with thicknesses in the range of several tens of nanometers capable of spanning micrometerwide pores have been prepared from Langmuir-Blodgett monolayers of crosslinked polyisoprene, [7] from triblock copolymers, [8] and most recently from nanocomposite membranes of polyelectrolytes with embedded gold nanoparticles.[9] Extremely flat and two-dimensionally extended objects have been termed "nanosheets" and prepared, for example, by exfoliation of layered inorganic materials, with a thickness down to 1 nm and lateral dimensions up to 100 lm. [10,11] In this communication, we show the controlled preparation of individual, freestanding nanosheets with the thickness of a single biphenyl molecule.…”

From Particle‐Assisted Wetting to Thin Free‐Standing Porous Membranes

“…Mixtures of TMPTMA and/or the colloid dispersions in chloroform and ethanol (the final solution contained 20 % ethanol and approximately 1 wt % of TMPTMA and silica colloid particles) were added to a Langmuir trough filled with water (equipment was identical to that described in ref. [26]). After evaporation of the solvent and lateral compression to a surface pressure of 15-20 10 À3 N m…”

Fabrication of Large Nanomembranes by Radical Polymerization of Multifunctional Acrylate Monomers

“…11 The ultimate tensile stress () and the ultimate elongation (") were determined by using the bulging technique. 17 Young's modulus was determined by the ''strain-induced elastic buckling instability for mechanical measurements (SIEBIMM)'' technique. 18,19 The results are summarized in Table I, together with those of the epoxy nanomembrane as reference.…”