Positron annihilation studies of bio-related N2S2-tetradentate ligands and their zinc complexes

Shaban, Shaban Y.; Mahmoud, K. R.; Sharshar, T.

doi:10.1016/j.radphyschem.2012.09.001

Cited by 6 publications

(3 citation statements)

References 34 publications

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“…As shown in our previous research [ 26 , 27 , 28 , 29 , 30 ], the solid’s nano-scale microstructure is studied. We report herein the application of the PALS for tracking the free volume size changes for synthesized NPS powder via a combination of the alkali chemical etching process and the ultra-sonication technique, starting with commercial silicon powder.…”

Section: Introductionmentioning

confidence: 99%

Nano-Porous-Silicon Powder as an Environmental Friend

et al. 2021

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Nano-porous silicon (NPS) powder synthesis is performed by means of a combination of the ultra-sonication technique and the alkali chemical etching process, starting with a commercial silicon powder. Various characterization techniques {X-ray powder diffraction, transmission electron microscopy, Fourier Transform Infrared spectrum, and positron annihilation lifetime spectroscopy} are used for the description of the product’s properties. The NPS product is a new environmentally friendly material used as an adsorbent agent for the acidic azo-dye, Congo red dye. The structural and free volume changes in NPS powder are probed using positron annihilation lifetime (PALS) and positron annihilation Doppler broadening (PADB) techniques. In addition, the mean free volume (VF), as well as fractional free volume (Fv), are also studied via the PALS results. Additionally, the PADB provides a clear relationship between the core and valence electrons changes, and, in addition, the number of defect types present in the synthesized samples. The most effective parameter that affects the dye removal process is the contact time value; the best time for dye removal is 5 min. Additionally, the best value of the CR adsorption capacity by NPS powder is 2665.3 mg/g at 100 mg/L as the initial CR concentration, with an adsorption time of 30 min, without no impact from temperature and pH. So, 5 min is the enough time for the elimination of 82.12% of the 30 mg/L initial concentration of CR. This study expresses the new discovery of a cheap and safe material, in addition to being environmentally friendly, without resorting to any chemical additives or heat treatments.

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Section: Introductionmentioning

confidence: 99%

Nano-Porous-Silicon Powder as an Environmental Friend

et al. 2021

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“…As part of our research [17][18][19][20][21] with a goal to study the nano scale microstructure of molecular solids, this study used PALS to evaluate how the number of end-functional groups affected the size and distribution of molecular level free volume in the chain-end-functionalized polystyrenes having a definite number of benzyl alcohol through systematic comparison with their corresponding polymers having the same definite number of C 8 F 17 groups. These chain-end-functionalized polystyrenes are distributed and linearly aligned in a double line at their chain-ends.…”

Section: Introductionmentioning

confidence: 99%

Positron annihilation spectroscopy of chain-end-functionalized polystyrenes with definite numbers of benzyl alcohol and perfluorooctyl groups

2019

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A series of well-defined chain-end-functionalized polystyrenes with a definite number of benzyl alcohol and perfluorooctyl groups [PS(BnOH) n & PS(BnORf) n , respectively] linearly aligned in a double line at the chain-ends were prepared and investigated using XRD, SEM, PALS and DBAR spectroscopy. XRD studies showed that PS(BnOH) n are crystalline and the degree of crystallinity increases with increasing the number of benzyl alcohol functionalities, while XRD pattern of PS(BnORf) n revealed that incorporating perfluorooctyl groups resulting in some fractions of polystyrene chains that were intercalated or broken between the interlayer spacing. PALS measurements yielded three lifetime components and the formation probabilities as well as lifetime of ortho-positronium in polymer series were found to be dependent on the chain-end polymer structure. DBAR measurements suggested that only one type of defect is present in the polymer samples.

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“…Positron annihilation spectroscopy (PAS) is one of techniques that can be used to investigate the structure of various types of materials. The PAS has been used to probe the defects and open-volumes in molecular structure compounds and metallic complexes [10][11][12][13][14]. The previous studies indicated that positron annihilation parameters are mainly dependent on the nature of the central metal ion of metal complex.…”

Section: Introductionmentioning

confidence: 99%