Hamdan Suhaimi

Surfactants and the stratum corneum lipids

Abstract A simplified mixture of model stratum corneum lipids was mixed with different surfactants to make a preliminary estimation of the influence of surfactants on the stratum corneum lipid structure. The results revealed differences between cationic and anionic surfactants and between anionic surfactants with different structures.

STRATUM CORNEUM LIPIDS IN A MODEL STRUCTURE

Abstract A model for the structure of the stratum corneum lipids was analyzed using small angle x-ray diffractometry and optical microscopy The small angle X-ray diffractograms showed the lipids to be partitioned in the hydrated acid/soap host layered structure between the methyl group layers. The exception is cholesterol which was entirely located in the acid/soap chains and which, in addition, attracted other compounds from the location between the methyl group layers.

Phase Behavior and Rheology of Mixed Nonionic Sugar-Based Surfactants

ABSTRACT The rheological properties of 40/60, 30/70, and 20/80 by weight ratio of methyl glucose sesquistearate (glucate SS) and PEG-20 methyl glucose sesquistearate (glucamate SSE-20) at 1-phase (Lα) and 2-phase (L1 + Lα) region were studied. These regions are fully developed lamellar liquid crystal (Lα) ranging from 29–31% water, lamella liquid crystal, and isotropic matrix which is closed Lα region (L1 + Lα) ranging from 16–19% water, and lamella liquid crystal in which birefringence is not prominent and isotropic matrix (L1 + Lα)′ ranging from 34–44% water. The viscosity, yield value and thixotropy behavior were studied at 80°C using a Brookfield viscometer. A pseudoplastic behavior exhibits at all the phases for mixed surfactants. The viscosity of mixed surfactants indicated as fall in the following order Lα > (L1 + Lα)′ > (L1 + Lα). The yield values of 40/60 and 20/80 exhibit the same ranking as the viscosity but not for 30/70. The highest plastic viscosity was observed in Lα region. The consistency index or viscosity index increased at Lα and it decreased in the flow index (flow index to describe the flow-curve, i.e., Newtonian, dilatant, pseudoplastic or plastic). The thixotropy behavior in that required a longer time to recover its structure of mixed surfactants showed at the Lα. Oily streaks pattern exhibits the biggest hysteresis loop.

Synthesis and toxicity test of magnetic nanoparticle via biocompatible microemulsion system as template for application in targeted drug delivery

This work reports the preparation of magnetic nanoparticles (FeNPs) using biocompatible W/O microemulsion for biomedical applications. W/O microemulsion was formed using decane as oil phase, water, tween 80 as non-ionic surfactant and hexanol as organic solvent. The synthesized FeNPs were characterised by using Fourier Transform Infrared Resonance Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The FTIR showed that Fe-O bond exist on 581cm−1 having strong magnetic strength whereas SEM showed the morphology surface of magnetic nanoparticles (FeNPs). Furthermore, analysis of XRD pattern magnetic nanoparticles (FeNPs) reveals a cubic iron oxide phase with good crystallize structure. Furthermore, toxicity test on human liver cells proved that it is 70% safe on human and proved to be a safety nanomedicine.This work reports the preparation of magnetic nanoparticles (FeNPs) using biocompatible W/O microemulsion for biomedical applications. W/O microemulsion was formed using decane as oil phase, water, tween 80 as non-ionic surfactant and hexanol as organic solvent. The synthesized FeNPs were characterised by using Fourier Transform Infrared Resonance Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The FTIR showed that Fe-O bond exist on 581cm−1 having strong magnetic strength whereas SEM showed the morphology surface of magnetic nanoparticles (FeNPs). Furthermore, analysis of XRD pattern magnetic nanoparticles (FeNPs) reveals a cubic iron oxide phase with good crystallize structure. Furthermore, toxicity test on human liver cells proved that it is 70% safe on human and proved to be a safety nanomedicine.

Synthesis and characterization of oleic acid surface modified magnetic iron oxide nanoparticles by using biocompatible w/o microemulsion for heavy metal removal

Oleic acid modified magnetic iron oxide nanoparticles (OA-MIONs) was prepared for removal of Cu2+ ion from aqueous solution. OA-MIONs was prepared by W/O microemulsion template which composed of mixed non-ionic surfactants and 1-hexanol as emulsifier. The effect of weight ratio of the constituent of microemulsion template on the physical and chemical properties of OA-MIONs was studied by characterization using Fourier transform infrared (FT-IR), scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) analysis. FT-IR spectra showed that all templates shared similar chemical structure with slight difference in the peak intensity. Scanning electron micrograph illustrated that the OA-MIONs synthesized via template with the lowest weight ratio of emulsifier to heptane had a more regular spherical shape and was well-distributed. XRD had confirmed that the identity of synthesized OA-MIONs was Fe3O4. Based on the characterization result, the template with lowest weight ratio of emulsifier to heptane was chosen for the heavy metal adsorption study. The adsorption capacity OA-MIONs as a function of pH, contact time and adsorbent dosage were studied. The adsorption process reached equilibrium for 90 minutes and successfully adsorbed 43% of Cu2+ ion from aqueous solution. The adsorption behavior was well described by Langmuir isotherm. The maximum adsorption capacity was determined and found to be 555.56 mg/g. The value of Langmuir equilibrium parameter, RL was found between 0 and 1, suggested that a favorable monolayer adsorption process had taken out.Oleic acid modified magnetic iron oxide nanoparticles (OA-MIONs) was prepared for removal of Cu2+ ion from aqueous solution. OA-MIONs was prepared by W/O microemulsion template which composed of mixed non-ionic surfactants and 1-hexanol as emulsifier. The effect of weight ratio of the constituent of microemulsion template on the physical and chemical properties of OA-MIONs was studied by characterization using Fourier transform infrared (FT-IR), scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) analysis. FT-IR spectra showed that all templates shared similar chemical structure with slight difference in the peak intensity. Scanning electron micrograph illustrated that the OA-MIONs synthesized via template with the lowest weight ratio of emulsifier to heptane had a more regular spherical shape and was well-distributed. XRD had confirmed that the identity of synthesized OA-MIONs was Fe3O4. Based on the characterization result, the template with lowest weight ratio of emulsifier to heptane...