Reliable and simple techniques for rapid assembly and patterning of colloid architectures advance the discovery and implementation of such nanomaterials. This work demonstrates rapid electrokinetic two-dimensional assembly of colloidal structures guided by the geometry of thin film heaters within a parallel-plate device. This system is designed to enable either independently addressable or mass...

We demonstrate non-contact remote photoacoustic spectroscopy in the mid-infrared region. A room-temperature-operated pulsed external-cavity quantum cascade laser is used to excite photoacoustic waves within a semitransparent sample. The ultrasonic waves are detected remotely on the opposite side of the sample using a fiber-optic Mach-Zehnder interferometer, thereby avoiding problems associated ...

A simple model for the motion of passive particles in a bath of active, self-propelled ones is introduced. It is argued that this approach provides the correct framework within which to cast the recent experimental results obtained by Wu and Libchaber [Phys Rev. Lett. 84, 3017 (2000)] for the diffusive properties of polystyrene beads displaced by bacteria suspended in a two-dimensional fluid fi...

The average glass transition temperatures, Tg, of thin homopolymer films exhibit a thickness dependence, Tg(h), associated with a confinement effect and with polymer-segment-interface interactions. The Tg's of completely miscible thin film blends of tetramethyl bisphenol-A polycarbonate (TMPC) and deuterated polystyrene (dPS), supported by SiO(x)/Si, decrease with decreasing h for PS weight fra...

This review compiles the work performed in the field of organic solid-state lasers with the hole-transporting organic molecule N,N ́-bis(3-methylphenyl)-N,N ́-diphenylbenzidine system (TPD), in view of improving active laser material properties. The optimization of the amplified spontaneous emission characteristics, i.e., threshold, linewidth, emission wavelength and photostability, of polystyren...

The development of nanoand micropatterned materials is a key component of advanced nanotechnology. We report herein, a photo-based method for patterning general-purpose polymer films. Patterned ultraviolet (UV) light irradiation of a thin polystyrene film under controlled temperature generates surface relief structures by mass transfer from shaded to irradiated areas. The resulting surface reli...

We present a simple method to quantitatively image the dielectric permittivity of soft materials at nanoscale using electrostatic force microscopy (EFM) by means of the double pass method. The EFM experiments are based on the measurement of the frequency shifts of the oscillating tip biased at two different voltages. A numerical treatment based on the equivalent charge method allows extracting ...

We report experimental findings of spontaneous perpendicular orientation and successive kinking microdomains in film specimens block copolymer by solution cast using selective solvent. These phenomena were firstly found out our experiments. It is notable that only conducting a straightforward sophisticated to obtain cylindrical lamellar because mainly reported methods utilize application extern...

Solvent annealing [1-3] has recently emerged as a powerful alternative to thermal annealing of block copolymer (BCP) thin films and nanocomposites. Taking a more general point of view, solvent treatment procedures, employing the selectivity of the solvents towards the different blocks, can produce new structures [4], and provide fascinating insights into the swelling kinetics and instabilities ...

We present a quantitative method for determining the viscoelastic properties of materials with nanometer spatial resolution. The approach is based on the atomic force acoustic microscopy technique that involves the resonant frequencies of the atomic force microscopy cantilever when its tip is in contact with a sample surface. We derive expressions for the viscoelastic properties of the sample i...