Papers by Keyword: Lyotropic Liquid Crystal

Abstract: Morus alba stem extract possesses several biological activities. However, skin delivery of the extract is limited by the stratum corneum. In this study, lamellar lyotropic liquid crystal (LLC) was investigated for the potential application in the skin delivery of M. alba stem extract. The four formulations were developed and incorporated with M. alba stem extract at 3% w/w. These formulations were stored at room temperature in light-protected containers for 3 months. The optical pattern under polarized light microscope, viscosity and remaining of the extract were determined. The skin penetration enhancing property of the formulations was investigated using excised porcine ear skin model. The results showed that all formulations remained stable after 3-month storage. The two formulations exhibiting good penetration enhancing properties were F3 consisting of PEG-7 glyceryl cocoate/n-Dodecane/Water/extract (55.29/19.40/22.31/3.00 %w/w) and F4 consisting of mixed Surfactant/n-Dodecane/Water/extract (48.50/4.85/43.65/3.00 %w/w). The mixed surfactant composed of PEG-7 glyceryl cocoate/PEG-40 hydrogenated castor oil/Glyceryl oleate (40/33.24/26.76 %w/w). It can be concluded that the lamellar LLC formulations developed in this study can be used as a carrier for delivering of M. alba stem extract. The components of the formulations which play important roles are the oil and the surfactant.

Abstract: This paper focused on synthesizing the surfactant lyotropic liquid crystals (LLCs) through mixing the coconut diethanol amide (6501), primary alcobol ethoxylate (AEO9) and water. The LLCs phases formed in the ternary system are thoroughly investigated by polarized optical microscopy (POM). The obtained LLCs were characterized by XRD and SEM in order to analysis the texture, structure and the transformation. In addition, the LLCs have been applied in the preparation of TiO₂ nanoparticles in our research. The obtained TiO₂ powder were characterized by XRD and SEM, more importantly, the results showed that the LLCs are effective in the process of synthesizing TiO₂ nanoparticles.

Abstract: The lamellar nanostructured yttrium films on α-Al₂O₃ substrates were successfully synthesized by electroless deposition using the lyotropic liquid crystalline templating strategy. The reaction of hydrazine hydrate and Y³⁺ dissolved within the aqueous domains of the lyotropic liquid crystalline phase produced the nanostructured yttrium films. The low-angle X-ray diffraction (XRD), transmission electron microscope (TEM) and scanning electron microscope (SEM) indicated that the as-resulted films possessed lamellar regular array of nanochannels with periodicity of 6 nm. With well-defined nanochannels and higher surface areas, the nanostructured films may find applications in the field of electronic materials.

Abstract: TiO₂ nanomaterials were synthesized in lyotropic liquid crystal formed by nonionic surfactant TritonX-100 and TiOSO₄ aqueous solution with NH₃•H₂O as precipitator. The lyotropic liquid crystals were characterized by means of POM and Low-angle XRD. FT-IR, TGA, XRD, TEM were used to characterize the TiO₂ samples. It was found that all the lytropic liquid crystal were in lamellar liquid crysal phase and after casting the micro-structure of the LLC phase, the TiO₂ samples were self-assemble to form lamellar, sphere and rod structures. According to the characterization results, possible formation mechanism was proposed.

Abstract: Phase behavior of ternary systems involving PEO-PPO-PEO block copolymer (Pluronic P123), room-temperature ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate [Bmim]PF6, and glycerol is investigated at 25 °C by using small-angle X-ray scattering (SAXS) techniques. In this ternary system, the structures formed in the binary P123/[Bmim]PF6 system, hexagonal phase (H1) and lamellar phase (Lα), are still obtained. At lower P123/[Bmim]PF6 ratio, the H1 phase can accommodate more than 30 % glycerol. At higher P123/[Bmim]PF6 ratio, the Lα phase only accommodates less than 2 % glycerol and Lα changes to H1 with increasing the glycerol content. Moreover, a phase separation takes place at a higher glycerol content. Solvatophobic interactions between hydrophobic groups of [Bmim]PF6 and P123, coulombic force existing in the polyoxyethylene chain and imidazolium cation, H-bond between P123 and glycerol, accompanying with the force ascribe to the nitrogen of the imidazole ring and the oxygen of alcohol are helpful for the formation of long-range ordered structure.

Abstract: A novel dendronized cellulose，ethyl cellulose grafted 3,4,5-tris[4-(dodecyloxy) benzyloxy] benzoate (EC-g-DOBOB), which is comprised of ethyl cellulose (EC) backbone with mesogenic moiety DOBOB (3,4,5-tris(4-(dodecyloxy)benzyloxy)benzoic acid) dendron grafted, was designed and synthesized. The structure of EC-g-DOBOB was investigated by means of FTIR, Both thermotropic liquid crystal and lyotropic liquid crystal behaviors of EC-g-DOBOB were studied by combination of DSC, POM and XRD. At room temperature EC-g-DOBOB demonstrated hexagonal columnar mesophase (Φ_h), with the column diameter 5.8 nm, besides it formed lyotropic cholesteric liquid crystal in concentrated chloroform solution with a planar texture.

Abstract: Amphiphilic molecules self-assemble lamellar phase process in lyotropic liquid crystal formed by liquid dishwash was investigated with optical microscopy as concentration increases from its isotropic phase to its lamellar phase. We demonstrated that liquid dishwash molecules could assemble themselves into lamellar phase when their concentration increases between one pieces of glass substrate. We discussed the formative processes of Maltese-cross structure and phase transition from isotropic to lamellar phase.

Abstract: The laser diffractions phenomenon of surrounding bubbles of lyotropic liquid crystal formed by sodium dodecylsulfonate were investigated with polarized optical microscope and helium-neon laser, respectively. The eleven orders of diffractions can be observed when a beam of helium-neon laser is perpendicularly incident on the surrounding bubbles of lyotropic liquid crystal formed by sodium dodecyl sulfonate. The wavelength of the incident light is 633nm. And we have calculated the periodicity, p, of the grating was 0.211mm, and the small diffraction angle was 0.1146o. So we have simulated the microstructure of surrounding bubbles in the lyotropic liquid crystal formed by sodium dodecyl sulfonate.

Abstract: Lyotropic liquid crystal synthesized by sodium dodecyl sulfonate in the mixed solvent of distilled water through make the different concentration. Using Polarized optical microscopy and ultraviolet-visible spectrometer and theoretical simulation, we have studied the relation between the samples concentration and light scattering. Our results have demonstrated that natural light scattering increased with the samples concentration increased. The results we have gotten now are almost equal to our theoretical simulation.