LB multilayers and superlattice films of erbium fatty acid salts

Multilayers of Y-type bilayers of pure and mixed erbium palmitate(EP), nonadecanate(Er) and behenate(EB) on CaF2 substrates were prepared by conventional Langmuir-Blodgett (LB) method. II is demonstrated that two systems composed of alternating bilayer of different fatty acid salts are unidimensional superlattices. These LB films were characterized by means of x-ray photoelectronic Spectrometry (XPS), FTIR and x-ray diffraction (XRD) measurements.

Superlattice structure of gold nanoparticles film deposited by Langmuir-Blodgett technique

Dodecanethiol-capped gold nanoparticles could spread on water subphase and be transferred by LB technique. The superlattice structure of gold nanoparticles multilayer was discussed.

Langmuir-Blodgett film formation from surfactant-capped zinc sulfide nanoparticles spread on water surface

The surfactant-capped ZnS nanoparticulate multilayer film has been fabricated by Langmuir-Blodgett(LB) technique. ZnS LB firm was investigated by the small-angle x-ray diffraction(XRD), atomic force microscopy(AFM) and transmission electron microscopy(TEM). The results indicate that ZnS nanoparticulate LB film is one-dimensional superlattice.

Preparation of SnO2 thin films with extremely preferred orientation along (101) plane by LB deposition technique

SnO2 thin films with extremely preferred orientation along (101) plane were made by LB technique and characterized by FTIR,, UV-visible, X-ray diffraction, X-ray photoelectron spectroscopy and SEM.

Preparation and characterization of DBSA doped polyaniline thin films

Stable monolayer of the polyaniline(PAn) doped with dodecyl benzenesulfonic acid(DBSA) can form on the pure water surface. The multilayer ultrathin film can be successfully deposited by Langmuir-Blodgett(LB) technique onto CaF2 substrate. The limiting mean molecular area and collapse pressure observed are 0.066 nm(2) and 35 mN m(-1), respectively. The multilayer LB film and casting film were all characterized by TR and UV-Vis-NIR spectroscopies.

Technique for determination of gold electrode area and its application of characterization in self-assembling process

Underpotential deposition(UPD) of copper at polycrystal gold surface under different concentrations has been studied, and its reversibility and stability in high concentration (0.2M CuSO4+0.IM H2SO4) have been demonstrated by cyclic voltermmetry and EQCM. A Valid approach to determine the gold electrode area in presence of adsorbed species has been provided by using Cu UPD method. Further, the growth kinetics of decane thiol on gold has also been investigated based on such a Cu UPD technique.

Fabrication and characterization of orientation-controlled thin films of distyryl benzene derivatives

Distyryl benzene derivatives (DSB-1 and DSB-2) were deposited on a KBr (001) surface. DSB-1 molecules took two kinds of orientations depending on the substrate temperature. On the other hand, DSB-2 grew epitaxially. The longitudinal axes of DSB-2 molecules were oriented parallel to the substrate surface.

Study of the effect of hydrogen bonding on the phase behaviour of p-nitro azobenzene derivatives with hydrophilic tails

The infrared spect ra of N-n-(4-nitrophenyl)azophenyloxyalkyldiethanolamines (Cn) are examined in the range of 4000-400 cm(-1) at different temperatures and the assignment of the fundamental vibrations given. Based on (1) the localization of the broad absorption band at 3456 cm(-1), and (2) attribution of the associated OH bands centred at 1410-1390, 1100, and 650-634 cm(-1) to, respectively delta OH deformation, nu C-O stretching and gamma OH out-of-plane bending, intermolecular hydrogen bonding between OH groups in the crystalline, liquid crystalline and isotropic states is proposed. By considering the results of FTIR, WAXD and DSC measurements, the molecular arrangement of C10 in its smectic A phase as consisting of hydrogen bonding and strong interaction between dipolar groups (NO,) is proposed. This may explain the high stability and high orientational ordering property of Cn compounds in the liquid crystalline state compared with that of n-bromo-1-[4-(4-nitrophenyl)azophenyl]oxyalkanes (Bn).

Structure and Conformation of 2,3,6, 7,10,11-hexakispentyloxytriphenylene by TEM and Computer Simulation

Experimental electron diffraction patterns and high resolution images were used to determine the space group and unit cell dimensions of 2,3,6,7,10,11-hexakispentyloxytriphenylene. Subsequently the molecular conformation was calculated by energy minimized package in Cerius2. Using this method, we got the HPT crystal structure: space group: P6/mmm; lattice type: hexogonal; the lattice parameters are a = b = 20.3 angstrom, c = 3.52 angstrom, = = 90 degrees, = 120 degrees. The core of HPT is not perpendicular to the column. The angle between a axis and HPT core plane is 9 degrees which cannot be seen in b-c projection. The simulated ED patterns and HREM images are good agreement with the experimental ED patterns and HREM images.

Photoluminescence study of Langmuir-Blodgett films of blend poly 3-(2-(5-chlorobenzotriazole)ethyl) thiophene

The multilayer Langmuir-Blodgett (LB) films of pr,ly 3-(2-(5-chlorobenzotriazole)ethyl) thiophene (PCBET) blended with amphibious arachidic acid (AA) were prepared and characterized. The photoluminescence intensity of the blend film was enhanced as the AA increased by a certain amount. The PCBET excimers were not formed in the blend LB films.

Structure and order of the discotic compound 2,3,6,7,10,11-hexakispentyloxytriphenylene as revealed by diffraction and molecular simulation studies

The aggregate structure of the discotic compound 2,3,6,7,10,11-hexakispentyloxytriphenylene (HPT) was studied both for the crystalline state and the liquid crystalline state by using electron crystallography and a molecular simulation approach. In the crystalline state, HPT was found to adopt an orthorhombic P-2212 space group with cell parameters a = 36.73 Angstrom, b = 27.99 Angstrom and c = 4.91 Angstrom. Molecular packing calculations were conducted to elucidate the molecular conformation and mutual orientational characteristics in the different states. Phase transitions and relationships are discussed from a structural point of view.

Direct visualization of collapse process of porphyrin monolayers and porphyrin exclusion for mixed monolayers at the air-water interface

The collapse process of porphyrin monolayers at the air-water interface was studied by Brewster angle microscopy and by compression-recompression isotherms. It was found that the start of collapse observed by BAM is accordant with that measured by compression-recompression isotherms. The behavior of mixed monolayers was studied also and the results showed that porphyrin islands were excluded from mixed monolayers at 35mN/m.

A preliminary study on chemistry of phenoxynaphthacenequinones

A preliminary study on the chemistry of 6-phenoxy-5,12-naphthacenesuinone derivatives was reported, It was found that the main product was 6-(N,N-dimethylamino)-5,12-naphthacenequinone when a reaction of 6-chloro-5,12-naphthacenequinone with 4-hydroxyazobenzenes in DMF was carried out under certain reaction conditions. When the reaction of 6-[4-(4-hydroxyphenyl)isopropyl)phenoxy]-5, 12-naphthacenequinone and epichlorohydrin was carried out in an acetone/DMF(V/V=2/1) mixed solvent and in the presence of K2CO3 and KI, a new phenoxynaphthacenequinone derivative,6,6'-[1-methylethylidenebis(4,1-phenyleneoxy)]bis(5,12-naphthacenequinone), was obtained.

Structure-property relationship of phenoxynaphthacenequinones and their relatives

Like 6-phenoxy-5,12-naphthacenequinone (1), 6-[4-(2-( 8-hydroxyphenyl) isopropyl)phenoxy]-5, 12-naphthacenequinone (2) and 6-naphthyloxynaphthacenequinone (6) showed normal photochromism, The relative initial rates of trans to ana photoconversion were in the order: 1, 100; 2, 37; 6, 21, 6-[4-(Phenylazo)phenoxyl-5,12-naphthacenequinone (3), 6-[4-(p-ethoxyphenylazo) phenoxy]-5,12-naphthacenequinone (4), 6-[4-(p-nitrophenylazo)phenoxy]-5,12-naph cenequinone (5) had only slight W-induced photochromism for the phenoxynaphthacenequinone photochrome. 6-(2-Nitrosonaphthyloxy)-5,12-naphthacenequinone (7) exhibited no photochromism and underwent irreversible photoreaction.

Synthesis of a new series of chiral Schiff's bases and their copper complexes

A new series of chiral Schiff's bases containing 2-hydroxybenzilideneaniline moieties and their copper complexes were synthesized and studied by differential scanning calorimetry, polarized optical microscopy, X-ray diffraction and EPR measurement. The results show that most of the Schiff's bases and only two of the copper complexes exhibited chiral smectic liquid crystal phases.