Muhammad Qasim Shaikh

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Positron annihilation lifetime spectroscopy (PALS), a method well established for the study of polymers, is employed to characterize the temperature dependence of the free volume through T(g) in the amorphous pharmaceutical Verapamil hydrochloride. From the PALS spectra analyzed with the routine LifeTime9.0 the size (volume) distribution of local free(More)
Positron annihilation lifetime spectroscopy (PALS) was used to study the microstructure of the free volume in the temperature range between 103 K and 393 K in phenylphthalein-dimethylether (PDE), a low-molecular-weight glass former. Using the routine LIFETIME9.0, the ortho-positronium (o-Ps) lifetime distribution was analyzed, and from this, the volume(More)
Barnacles attach to a wide variety of surfaces underwater and show substrate-specific adhesion mechanisms. Investigating and understanding these mechanisms is a key for developing new technical adhesives. We expected open volume (porosity) at the sub-nanometre scale to occur in barnacle adhesive. With positron annihilation lifetime spectroscopy (PALS) it is(More)
Positron annihilation lifetime spectroscopy (PALS) is employed to characterize the temperature dependence of the free volume in two van der Waals liquids: 1, 1'-bis(p-methoxyphenyl)cyclohexane (BMPC) and 1, 1'-di(4-methoxy-5-methylphenyl)cyclohexane (BMMPC). From the PALS spectra analysed with the routine LifeTime9.0, the size (volume) distribution of local(More)
The microstructure of the free volume and its temperature dependence in polymethylphenylsiloxane (PMPS) have been examined using positron annihilation lifetime spectroscopy (PALS) and pressure-volume-temperature experiments. The hole-free volume fraction h and the specific hole-free and occupied volumes, Vf=hV and Vocc=(1-h)V, were estimated employing the(More)
The aim of this study was to characterize the process of atomization and drying of layer-by-layer emulsions containing lecithin (single layer emulsion) and lecithin/chitosan (bilayer emulsion) and the oxidative stability of the microcapsules during storage. For this purpose, the analysis of the emulsion spray droplet size during two-fluid nozzle and rotary(More)
Positron annihilation lifetime spectroscopy (PALS) and pressure-volume-temperature (PVT) experiments were performed to characterize the temperature dependent microstructure of the hole free volume in the low molecular weight glass-former phenyl salicylate (salol). The PALS spectra were analyzed with the new routine LT9.0 and the volume distribution of(More)
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