A Poly(vinyl alcohol)/Carbon‐Black Composite Film: A Platform for Biological Macromolecule Incorporation

Abstract

A detailed procedure for growing LC templated PEDOT films on ITO is given elsewhere [10]. Absorption spectra were collected on a Cary 500 UV/VIS/NIR spectrometer in double beam mode with a linearly polarizing filter (Edmund Optics A43-785) mounted on a rotating goniometer in the sample beam. Spectra were normalized to the baseline absorption of the filter and the ITO substrate. Substrates for four-probe conductivity measurements were photolithographically patterned using Clariant AZ1518 photoresists and the exposed ITO was removed with HCl. Patterned substrates were cleaned and polymerized as above. After washing and removal of the LC template, PEDOT films were cast with a 20 wt.-% solution of a thermosetting poly(amide-imide) (42 827-2, Aldrich) in 1-methyl-2-pyrrolidinone (NMP), heated to 150 C for 2 h; the resulting film was lifted off, transferring the PEDOT film from ITO to the insulating polyamide substrate. For multi-domain film conductivity measurements, Au electrodes were e-beam evaporated through a shadow mask across narrow strips of PEDOT. For single domain measurements, probes were contacted directly to the PEDOT film (Fig. 3a). A Keithley 2400 source meter was used to measure I±V curves for LC templated and nontemplated PEDOT, and both exhibited ohmic behavior. Uncertainty values given are a 95 % confidence interval for the mean based on ten samples. Film thickness was measured with a Tencor P10 profilometer. 30 nm thick PEDOT films for XPS were polymerized on Au coated Si substrates and studied using an Omicron ESCA Probe XPS with an Al Ka source operating at 14 kV. Binding energies were calibrated using the Au 4f peak (84.0 eV). After background subtraction, relative atomic composition was determined by integrating the C 1s (286.0 eV), S 2p (163.7 eV) and Cl 2p (200.4 eV) peaks and multiplying by instrument sensitivity factors determined for C, S, and Cl from known standards.

Thermo-Optical Arrays of Flexible Nanoscale Nanomembranes Freely Suspended over Microfabricated Cavities as IR Microimagers

“…Robust and flexible nanocomposite membranes have received increasing attention as a result of their unique micromechanical properties critical for prospective applications in microsensor technologies. − These flexible free-standing membranes are considered as prospective sensing elements in ultrasensitive mechanical, optical, and biological sensors and are extremely suitable for the assembly into lightweight and portable devices. − With the introduction of microelectromechanical systems technology, traditional sensors are being reinvented in a miniaturized form, such as Golay photothermal cells, which are based on pneumatically mediated membrane deflections − Layer-by-layer (LbL) assembly, which facilitates the fabrication of versatile multilayer structures, − has been successfully used to fabricate a variety of nanoscale composite membranes with an overall thickness ranging from several nanometers to micrometers. − …”

Recent Research Progress on Polymer Grafted Carbon Black and Its Novel Applications

“…Brott et al reported abiomimetic solid-state thermal sensor based on the incorporation of thermosensitive protein TlpA with poly (vinyl alcohol) (PVA) matrix doped with CB and poly (ethylene glycol) (PEG) as plasticizer (Brott et al, 2004). In the detector array, CB served as the provider of necessary electrical conductivity to polymer film and athermal absorber.…”

A temperature-responsive carbon black nanoparticle prepared by surface-induced reversible addition–fragmentation chain transfer polymerization

“…Unfortunately, the applications of carbon black in developing new materials have been studied very little until now. Stone et al incorporated protein into the poly(vinyl alcohol)/ carbon black matrix to translate the change in the protein's conformation as a change in electrical resistance [26]. Akashi et al found that the poly(N-isopropylacrylamide) gel including carbon black nanoparticles was a kind of light-modulation material because PNIPAAm/carbon black gel exhibited a volume phase transition from swollen to shrunken at 34 C, resulting in a color change below or above 34 C [27,28].…”