Papers by Keyword: Langmuir-Blodgett Films

Abstract: To examine perspectives of nanoparticle films in the role of active elements in strain sensors, morphological and electrical properties of self-assembled Au nanoparticle monolayer prepared by modified Langmuir-Schaefer technique onto supporting Mylar foil were studied under elongation. Along the probing of electrical response (characterized by the gauge factor of about 60), the small-angle x-ray scattering (SAXS) characterization assessed an average interparticle distance change, which was shown to vary proportionally to the substrate elongation. The approach allowed to unambiguously address the mechanism of the deformation-resistivity transduction.

Abstract: A new Diels-Alder Adduct of C₆₀ with 1,1’-biindene (CB) has been synthesized. The Langmuir trough study of this new fullerene derivative indicates that floating film could form monomolecular thick film at the air/water interface at lower concentration, and can be well transferred the floating mixed CB and arachidic acid film onto substrates using the Langmuir-Blodgett (LB) technique. In the case of the mixed film, high quality films with thickness of up to 50 layers could be readily built up. The absorption variation with film thickness at 255nm was measured, indicating good LB deposition up to 50 layers.

Abstract: The Fe2O3 and CoFe2O4 nanoparticle-based Langmuir-Blodgett lms for sensingof nitrogen dioxide (NO2) and acetone vapours have been explored. Both the sensitivity of thechemiresistors and dynamic properties, such as the response/recovery time, have been probed independence of the number of nanoparticle monolayers and working temperatures. The responseof 23 at the NO2 concentration of 1 ppm has been monitored suggesting the pertinent sensitivityin the deep sub-ppm range, i.e. approaching the canine detection limit, and likewise implyingthe supposable detection of nitrate-based explosives.

Abstract: A series of novel copolymers [p (AOBHA-co-NPMA)] containing 2-Allyloxy-N-benzylidene hexadecylamine (AOBHA) as film formation material and β-naphtayl methacrylate (NPMA) as photosensitive group were synthesized by free-radical polymerization. The copolymers could form stable condensed monolayer at air/water interface and be transformed onto solid substrates. Positive-tone patterns with the resolution of 0.75 μm of the copolymers Langmuir-Blodgett (LB) films with 35 layers were fabricated by deep UV irradiation, followed by developing with acetone. The etched gold patterns with resolution of 0.75 μm were also obtained, showing that the copolymer has enough resistance to wet etching suitable for fabricating photomask. The mechanism of photolysis was also investigated by UV and GPC, in which showed that the scission of main and side chain of p (AOBHA-co-NPMA) LB films occurred at the same time.

Abstract: Some trigonal Schiff base amphiphiles with symmetric aromatic cores and different substituted headgroups were designed and their interfacial assemblies were investigated. When on the metal ions subphases, an in situ coordination can occur for all compounds. The coordinated films could be transferred onto solid substrates and subsequently characterized by morphological characterization with atomic force microscopy measurement. Depending on the trigonal molecular structures and different substituted headgroups, these amphiphiles showed distinct assembly behaviors in the organized molecular films.