Study of photoreaction processes of PDA Langmuir films

Abstract

Systems Analysis for the Control of Toxics. S. K. Friedlander wishes to express his appreciation for a senior Humboldt award from the German government during the course of this research. Nomenclature A0 preexponential factor, gg/(s-m1 2'Torr) dp diameter of elementary soot spheroids, nm dp0 initial diameter of soot spheroids, 20 nm £a activation energy, kcal/mol k surface reaction rate constant, #ig/(s-m2) kB Boltzmann constant, 1.38 X 10"18 erg/mol m mass of an oxygen molecule, 5.31 X 10"23 g M soot loading per cross sectional area of the filter, jitg/cm2 Mcat catalyst loading per filter cross sectional area, mg/cm2 MWc molecular weight of carbon, 12 g/mol N number of soot spheroids in filter/cm2 iVAv Avogadro number, 6.023 X 1023 mol"1 Pq2 partial pressure of oxygen, Torr t time, s if total reaction time, s T temperature, K p density of the elementary soot spheroid, 2 g/cm3

A Self‐Contained Microelectrochemical Cavity System Comprised of a Polymer and Phospholipid Membrane Suspended over a Picoliter Volume

“…The general shape is consistent with other reports in the literature [24,33]. The collapse pressure occurs at ca.…”

“…When we obtained isotherms with a subphase containing CaCl 2 alone (1 mM ± 0.1 M), the collapse pressure was higher (40 ± 44 mN/m). The presence of a divalent cation, like Ca 2 , increases the number of bridges between PDA molecules, making the Langmuir film more solid [24]. The lower collapse pressure is due to the more complex subphase composition.…”

“…The Au layer surrounding the opening to the cavity serves as an anchoring site to the membrane through electrostatic linkage of Ca 2 to covalently-attached SAMs of mercaptoundecanoic acid (MUA). One component of the membrane is 10,12-pentacosadiyonic acid (PDA) that is UV-polymerized in a 2-dimensional fashion in a L-B trough [24,25] to supply scaffolding, while dipalmitoylphosphatidyl choline (DPPC) phospholipids are added to fill imperfections and provide further amphiphilicity and fluidity to the membrane, which is transferred to the SAMmodified microcavity chip by emersion. Evaluation of the solution entrapped in the microcavity under the membrane is possible because it contains 10 mM K 4 Fe(CN) 6 in an electrolyte of 0.1 M KCl and 1 mM CaCl 2 .…”

Photopolymerization of Diacetylene Langmuir-Blodgett Films on an Azobenzene-Containing Monolayer

“…30, No. 8,1998 CONCLUSIONS It is demonstrated in this work that the photopolymerization behavior of a diacetylene LB film is controlled by the trans/cis photoisomerization of Azbased command layer. Achievement of this surfacemediated discrimination requires dry atmospheres in which the lateral mobility of the supporting Az layer is frozen.…”

“…30, No. 8,1998 d m -3 ) was spread onto pure water at 9°C filled in a USI FSD-110 Langmuir trough. The spread film was compressed at a speed of 5 mm min -1 , and the upstroke transfer was achieved at a surface pressure of 3 mN m -1 and a speed of I mm min -1 .…”