Structure and macroscopic tackiness of ultrathin pressure sensitive adhesive films.

Ultrathin layers of the statistical copolymer P(nBA-stat-MA) with a majority of n-butyl acrylate (nBA) and a minority of methyl acrylate (MA) are characterized with respect to the film morphology and the mechanical response in a probe tack test. The probed copolymer can be regarded as a model system of a pressure sensitive adhesive (PSA). The films are prepared by spin-coating which enables an easy thickness control via the polymer concentration of the solution.

Kinetics of collapse transition and cluster formation in a thermoresponsive micellar solution of P(S-b-NIPAM-b-S) induced by a temperature jump.

Structural changes at the intra- as well as intermicellar level were induced by the LCST-type collapse transition of poly(N-isopropyl acrylamide) in ABA triblock copolymer micelles in water. The distinct process kinetics was followed in situ and in real-time using time-resolved small-angle neutron scattering (SANS), while a micellar solution of a triblock copolymer, consisting of two short deuterated polystyrene endblocks and a long thermoresponsive poly(N-isopropyl acrylamide) middle block, was heated rapidly above its cloud point. A very fast collapse together with a multistep aggregation behavior is observed.

Tailoring the near-surface composition profiles of pressure-sensitive adhesive films and the resulting mechanical properties.

We present a possibility of tailoring the near-surface composition profiles of pressure sensitive adhesive (PSA) films by an exposure to atmospheres of different relative humidities (RHs). The statistical copolymer P(EHA-stat-20MMA) with a majority of ethylhexylacrylate (EHA) and a minority of methylmethacrylate (MMA), being cast from a toluene based solution, is chosen as a model system. The near-surface composition profile is probed with X-ray reflectivity.

Influence of film thickness on the phase separation mechanism in ultrathin conducting polymer blend films.

The film morphology of thin polymer blend films based on poly[(1-methoxy)-4-(2-ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) and poly(N-vinylcarbazole) (PVK) is probed as a function of film thickness. Blend films are prepared with spin-coating of polymer solutions with different concentrations on top of solid supports. The blending ratio of both conducting polymers is kept constant.

Hierarchically structured titania films prepared by polymer/colloidal templating.

Hierarchically structured titania films for application in hybrid solar cells are prepared by combining microsphere templating and sol-gel chemistry with an amphiphilic diblock copolymer as a structure-directing agent. The films have a functional structure on three size scales: (1) on the micrometer scale a holelike structure for reduction of light reflection, (2) on an intermediate scale macropores for surface roughening and improved infiltration of a hole transport material, and (3) on a nanometer scale a mesoporous structure for charge generation. Poly(dimethyl siloxane)-block-methyl methacrylate poly(ethylene oxide) (PDMS-b-MA(PEO)) is used as a structure-directing agent for the preparation of the mesopore structure, and poly(methyl methacrylate) (PMMA) microspheres act as a template for the micrometer-scale structure.

Preservation of the morphology of a self-encapsulated thin titania film in a functional multilayer stack: an X-ray scattering study.

Tailoring of the titania morphology is achieved by the combination of a triblock copolymer, acting as structure-directing agent, and a sol-gel chemistry enabling the incorporation of the provided inorganic material (titania) into the selected phase of the triblock copolymer. Spin-coating of the solution on FTO-coated glass, followed by plasma etching and calcination of the thin film results in the formation of self-encapsulated crystalline titania nanostructures. The fabricated nanostructures are coated stepwise with dye, conductive polymers and gold forming a functional multilayer stack.