A number of new compounds of two series have been shown by miscibility studies and optical microscopy to exhibit the hitherto rare smectic F phase. An example of each series has been chosen for detailed X-ray structural investigation : terephthalylidenebis-4-n-pentylaniline (TBPA) and 4-(2'-methyl butylphenyl 4'-n-octyloxybiphenyl-4-carboxylate) (80SF). The structure of the SF phase has been de...

We measured the effects of two branched-chain analogs of distearoyl-phosphatidylcholine, containing either a methyl or an n-butyl group at the 8 position, on the bilayer to hexagonal phase transition temperature of dielaidoylphosphatidylethanolamine. The former compound raised the bilayer to hexagonal phase transition temperature while the latter compound lowered it. The opposite effects of the...

The crystallization of molecules with polar and hydrophobic groups, such as ionic amphiphiles and proteins, is of paramount importance in biology and biotechnology. By coassembling dilysine (+2) and carboxylate (-1) amphiphiles of various tail lengths into bilayer membranes at different pH values, we show that the 2D crystallization process in amphiphile membranes can be controlled by modifying...

Hexagonal molybdenum oxide (h-MoO(3)) was synthesized by a solution based chemical precipitation technique. Analysis by X-ray diffraction (XRD) confirmed that the as-synthesized powder had a metastable hexagonal structure. The characteristic vibrational band of Mo-O was identified from Fourier transform infrared spectroscopy (FT-IR). Scanning electron microscopy (SEM) and transmission electron ...

A simple two order-paraIneter Ginzburg-Landau theory for binary mixtures of water and amphiphile is introduced. The amphiphile concentration is described by a scalar, the orientational degrees of freedom of the amphiphile by a vector order parameter. Phase diagrams are calculated by minimizing the free energy functional. Several ordered lyotropic phases of lamellar, hexagonal, inverse hexagonal...

The thickness-dependent electronic states and physical properties of two-dimensional materials suggest great potential applications in electronic and optoelectronic devices. However, the enhanced surface effect in ultra-thin materials might significantly influence the structural stability, as well as the device reliability. Here, we report a spontaneous phase transformation of gallium telluride...

The first example of polytypism in the I-II-V semiconductors has been demonstrated with the synthesis of cubic LiZnSb by a low-temperature solution-phase method. This phase exhibits a unique coloring pattern that is novel for this class of compounds. The choice of site configuration has a considerable impact on the band structure of these materials, which in turn affects the transport propertie...

A number of carbobenzoxy-dipeptide-amides raise the bilayer to hexagonal phase transition temperature of dielaidoylphosphatidylethanolamine (stabilizes the bilayer). The potency of the peptides in stabilizing the bilayer phase is Z-Tyr-Leu-NH2 = Z-Gly-Phe-NH2 greater than Z-Ser-Leu-NH2 greater than Z-Gly-Leu-NH2 greater than Z-Gly-Gly-NH2. A linear correlation was found between the respective H...

Membrane pores spontaneously formed by antimicrobial peptides in membranes were crystallized for the first time by manipulating the sample hydration and temperature. Neutron diffraction shows that magainins and protegrins form stable pores in fully hydrated fluid membranes. At lower hydration levels or low temperature, the membrane multilayers crystallize. In one crystalline phase, the pores in...