scholarly journals Tin(IV) Compounds as Photo-Stabilizers for Irradiated Surfaces of Poly(Vinyl Chloride) Films

Surfaces ◽  
2021 ◽  
Vol 4 (4) ◽  
pp. 279-292
Author(s):  
Alaa Mohammed ◽  
Mohammed Kadhom ◽  
Emad Yousif
Keyword(s):  
Vinyl Chloride ◽  
Room Temperature ◽  
Uv Light ◽  
Weight Ratio ◽  
Force Microscopy ◽  
Content Change ◽  
Atomic Force ◽  
Poly Vinyl Chloride ◽  
Before And After ◽  
Scanning Electron

Dimethyl-organotin(IV) valsartan (Me2SnL2) and dichlorostannanediyl valsartan (SnL2Cl2) complexes were synthesized, characterized, and applied as Poly(vinyl chloride) (PVC) photo-stabilizers. The complexes were loaded within the PVC films in a weight ratio of 0.5%, and the modified films were irradiated to a UV light of 313 nm wavelength for 300 h at room temperature. The efficiency of the complexes-filled films was compared with the plain one and evaluated before and after irradiation by Fourier transform infrared spectroscopy, weight loss, gel content, change in viscosity, atomic force microscopy, and field emission scanning electron microscopy. The SnL2Cl2 complex had higher activity than the Me2SnL2 complex to retard the PVC’s photodegradation by several mechanisms.

Improving the Photostabilization of Poly(vinyl chloride) Using 4-(benzylideneamino)benzenesulfonamide Tin Complex

2022 ◽  
Vol 16 (1) ◽  
pp. 23
Author(s):  
Hassan Ghani ◽  
Emad Yousif ◽  
Mohammed Kadhom ◽  
Waled Abdo Ahmed ◽  
Muhammad Rahimi Yusop ◽  
...  
Keyword(s):  
Weight Loss ◽  
Vinyl Chloride ◽  
Photo Degradation ◽  
Viscosity Change ◽  
Force Microscopy ◽  
Atomic Force ◽  
Poly Vinyl Chloride ◽  
Pvc Film ◽  
Before And After ◽  
The Impact

The photostabilization of poly (vinyl chloride) (PVC) film filled with an organotin complex in its structure was examined and compared with the blank PVC film. The organotin (IV) complex that contains 4-(benzylideneamino) benzenesulfonamide as a ligand was synthesized and applied as a PVC photostabilizer. The impact of the complex on the polymer was assessed by comparing the properties of the films with and without the complex, before and after irradiation, using Fourier transform infrared spectroscopy, weight loss, viscosity change, atomic force microscopy, and field emission scanning electron microscopy (FE-SEM). Results showed that the complex film had lower weight loss, gel content, and molecular weight deterioration than the plain PVC film. Also, surfaces of the complexes-filled films were smoother, less lumpy, and more homogeneous. These findings were obtained via the FE-SEM and light microscope images and confirmed by measuring the roughness factor. The organotin (IV) complex proved its activity in delaying the photo-degradation of PVC by several mechanisms. Ultimately, the Tin complex has effectively protected the PVC film against irradiation. The photostabilization of poly (vinyl chloride) (PVC) film filled with an organotin complex in its structure was examined and compared with the blank PVC film. The organotin (IV) complex that contains 4-(benzylideneamino) benzenesulfonamide as a ligand was synthesized and applied as a PVC photostabilizer. The impact of the complex on the polymer was assessed by comparing the properties of the films with and without the complex, before and after irradiation, using Fourier transform infrared spectroscopy, weight loss, viscosity change, atomic force microscopy, and field emission scanning electron microscopy (FE-SEM). Results showed that the complex film had lower weight loss, gel content, and molecular weight deterioration than the plain PVC film. Also, surfaces of the complexes-filled films were smoother, less lumpy, and more homogeneous. These findings were obtained via the FE-SEM and light microscope images and confirmed by measuring the roughness factor. The organotin (IV) complex proved its activity in delaying the photo-degradation of PVC by several mechanisms. Ultimately, the Tin complex has effectively protected the PVC film against irradiation.

scholarly journals The Morphology and Performance of Poly(Vinyl Chloride) Containing Melamine Schiff Bases against Ultraviolet Light

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 803 ◽  
Author(s):  
Gamal El-Hiti ◽  
Mohammad Alotaibi ◽  
Ahmed Ahmed ◽  
Basheer Hamad ◽  
Dina Ahmed ◽  
...  
Keyword(s):  
Ultraviolet Light ◽  
Vinyl Chloride ◽  
Schiff Bases ◽  
Average Molecular Weight ◽  
Hydroxyl Group ◽  
Force Microscopy ◽  
Polymeric Surface ◽  
Atomic Force ◽  
Poly Vinyl Chloride ◽  
And Performance

Five Schiff bases derived from melamine have been used as efficient additives to reduce the process of photodegradation of poly(vinyl chloride) films. The performance of Schiff bases has been investigated using various techniques. Poly(vinyl chloride) films containing Schiff bases were irradiated with ultraviolet light and any changes in their infrared spectra, weight, and the viscosity of their average molecular weight were investigated. In addition, the surface morphology of the films was inspected using a light microscope, atomic force microscopy, and a scanning electron micrograph. The additives enhanced the films resistance against irradiation and the polymeric surface was much smoother in the presence of the Schiff bases compared with the blank film. Schiff bases containing an ortho-hydroxyl group on the aryl rings showed the greatest photostabilization effect, which may possibly have been due to the direct absorption of ultraviolet light. This phenomenon seems to involve the transfer of a proton as well as several intersystem crossing processes.

Enhancing Titanium Stability in Fusayama Saliva Using Electrochemical Elaboration of TiO2 Nanotubes

2008 ◽  
Vol 59 (6) ◽  
Author(s):  
Isabela Man ◽  
Cristian Pirvu ◽  
Ioana Demetrescu
Keyword(s):  
Tio2 Nanotubes ◽  
Room Temperature ◽  
Large Range ◽  
Stability Evaluation ◽  
X Ray ◽  
Force Microscopy ◽  
Atomic Force ◽  
Before And After ◽  
The Stability ◽  
Tube Structure

Titanium having low density, stability and biocompatibility, is one of the most promising biomaterial of the century even with the natural passive stratum [1,2], but building a nano-tube structure in the last decade using various procedure could lead also to an improvement of a quite large range of properties important in applied chemistry. The aim of the paper is to elaborate electrochemically TiO2 nanotubes and to evaluate the stability increase of Titanium in Fusayama saliva changing the surface morphology from micro TiO2 to TiO2 nanotubes. Anodization at room temperature in a mixture of (NH4)2SO4 and NH4F, was the choice of nanotubes structures elaboration, and cyclic voltammetry was the procedure of stability evaluation. The surface analysis was performed using scanning electron microscopy (SEM), energy-dispersive X-ray microanalysis (EDAX), and atomic force microscopy before and after anodization.

Vinyl-functionalized polysiloxane as radical scavenger during the degradation of poly(vinyl chloride)

2019 ◽  
pp. 089270571989505
Author(s):  
Xiaojian Zhou ◽  
Magda E Tawfik ◽  
Salwa H El-Sabbagh ◽  
Sara N Ghanem ◽  
Hisham A Essawy
Keyword(s):  
Electron Microscopy ◽  
Vinyl Chloride ◽  
Thermal Processing ◽  
Uv Light ◽  
Radical Scavenger ◽  
Poly Vinyl Chloride ◽  
Siloxane Polymer ◽  
Residual Weight ◽  
Scanning Electron ◽  
Silicone Polymer

Siloxane polymer containing vinyl groups was blended with poly(vinyl chloride) (PVC) to convey plasticization and stability against decomposition, that is likely to happen during thermal processing or following exposure to the ultraviolet (UV) light. The immiscibility between silicone rubber and PVC was proved from images acquired using scanning electron microscopy (SEM), which revealed worsening of the situation at higher loading (10 wt%) of silicone polymer. The thermal degradation profiles indicated that the inclusion of silicone polymer did not affect the thermal resistance significantly between 200°C and 350°C. However, it protected the matter from intensive decomposition at higher temperatures and increased the residual weight. Fourier transform infrared spectra were collected for the blends after exposure to UV radiation for 168 h, from which the absence of appreciable dehydrochlorination or change in the nature of the material was ensured. The hampering of dehydrochlorination is expected to have proceeded by instant attack of any appearing radicals on PVC backbone onto vinyl groups of the silicone polymer and buildup of a network structure.

Measuring the Changes in InP Morphological and Electrical Specifications Caused by Oxygen Ion Implantation

2011 ◽  
Vol 264-265 ◽  
pp. 1312-1317
Author(s):  
A.H. Ramezani ◽  
M.R. Hantezadeh ◽  
M. Ghoranneviss ◽  
A.H. Sari
Keyword(s):  
Surface Roughness ◽  
Ion Implantation ◽  
Room Temperature ◽  
Implantation Dose ◽  
Force Microscopy ◽  
Oxygen Ions ◽  
Oxygen Ion ◽  
Atomic Force ◽  
Before And After ◽  
Oxygen Ion Implantation

This paper is the results of oxygen ion implantation on morphological and electrical properties of indium phosphate (InP) semiconductor wafers. The oxygen ions were implanted at 30 keV and various doses in the range between 5×10 15 to 5×10 17 ions/cm2 and at nearly room temperature. The changes in surface roughness and resistivity before and after the implantation is studied using atomic force microscopy (AFM) and four-point probes technique, respectively. The results show that the resistivity is depend on the ion implantation dose. In addition, the RMS roughness of implanted samples dramatically increases by accumulation of oxygen ion dose.

scholarly journals Nonuniform Morphology and Luminescence Properties of a Molecular Beam Epitaxy GaN Film from Atomic Force Microscopy, Scanning Electron Microscopy and Cathodoluminescence

1997 ◽  
Vol 2 ◽  
Author(s):  
L.-L. Chao ◽  
G. S. Cargill ◽  
C. Kothandaraman ◽  
D. Cyr ◽  
G. Flynn ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Room Temperature ◽  
Force Microscopy ◽  
Luminescence Efficiency ◽  
Atomic Force ◽  
Background Material ◽  
Gan Film ◽  
Scanning Electron

Complex faceted features of micrometer sizes and with intense luminescence rise 200-300 nm above the surface of a GaN thin film grown by molecular beam epitaxy on (0001) sapphire. Cathodoluminescence measurements at room temperature and at 8K were used to investigate the luminescence properties of these microfeatures in comparison with those of the background GaN material. The morphology of the micro-features was studied by scanning electron microscopy and by atomic force microscopy.GaN and related compounds have been considered as promising materials for light emitting devices in the short wavelength visible and UV spectral regions because of their direct, wide band gaps and high luminescence efficiency. Remarkable, rapid success has been achieved in developing devices based on III-V nitrides, which allows these material systems to rival other systems under development [1]. Blue-green LEDs fabricated from InGaN/AlGaN double-heterostructure layers on sapphire substrates by Nichia Chemical Industries in Japan are commercially available, despite the presence of high extended defect densities in the 1010 /cm2 range [2]. In December 1995, an important milestone in the development of nitride lasers was reached; Nakamura et al. in Nichia demonstrated the first nitride-based laser diode which operated at 417 nm under pulsed conditions at room temperature [3].The morphology and spatial distribution of luminescence in GaN thin films have been investigated by several research groups [4], [5], [6], although most efforts have been directed to developing appropriate growth conditions for improved film quality. From observations by scanning electron microscopy (SEM) and atomic force microscopy (AFM), Trager-Cowan et al. described an MBE-grown GaN film which contained an assembly of oriented hexagonal crystallites rising above a background of polycrystalline or amorphous material [4]. All the crystallites, oriented in a similar fashion, had roughly the same sizes, 1 or 2 μm across a hexagonal face and about 1 μm high. These crystallites were much brighter than the surrounding background material in panchromatic low-temperature cathodoluminescence (CL) images. Trager-Cowan et al. concluded that the crystallites were of better quality than the background material. They also observed a green emission band, attributed to impurities, which became weaker for higher electron beam voltages, generating luminescence from deeper in the film. From this observation, they concluded that higher quality material is located closer to the film's outer surface. Spatial variation of the luminescence efficiency from MOCVD-grown films has also been observed by Ponce et al[5]. in their room-temperature CL microscopy studies. Their results showed significant nonuniformities in both the band-edge and yellow band emissions. Although they reported no faceted island structures, one of their samples had “marked surface features” and consisted of hexagonal crystals 10 to 50 μm in diameter. The crystals gave strong band-to-band (364 nm) luminescence.In this paper, the morphology of a GaN film grown on (0001) sapphire by MBE is characterized by SEM and AFM, and CL measurements are used to investigate the luminescence properties of the film at room temperature and at 8K. Some regions of this film are similar to the one described by Trager-Cowan et al. [4] in having micron sized, brightly luminescent islands. The hexagonal facet angles and bright luminescence of islands in our film also resemble the larger scale, more regularly shaped hexagonal crystals of Ponce et al. [5]. These regions lie on the boundary of excess gallium growth conditions. Our results differ from those of Trager-Cowan in terms of the island morphologies and the spectral character of luminescence from the islands and from the background material. Possible causes of the large variations in luminescence efficiency are discussed.

scholarly journals A Surface Morphological Study, Poly(Vinyl Chloride) Photo-Stabilizers Utilizing Ibuprofen Tin Complexes against Ultraviolet Radiation

Surfaces ◽  
2020 ◽  
Vol 3 (4) ◽  
pp. 579-593
Author(s):  
Baraa Watheq ◽  
Emad Yousif ◽  
Mohammed H. Al-Mashhadani ◽  
Alaa Mohammed ◽  
Dina S. Ahmed ◽  
...  
Keyword(s):  
Vinyl Chloride ◽  
Uv Light ◽  
Average Molecular Weight ◽  
Optical Microscope ◽  
Conjugation System ◽  
X Ray ◽  
Poly Vinyl Chloride ◽  
Before And After ◽  
Tin Complexes ◽  
Photo Stability

In this work, three Ibuprofen tin complexes were synthesized and characterized by Fourier Transform Infrared spectroscopy (FTIR), 1H and 119Sn-Nuclear Magnetic Resonance (NMR), and Energy Dispersive X-ray (EDX) spectroscopies to identify the structures. The complexes were mixed separately with poly(vinyl chloride) (PVC) to improve its photo-stability properties. Their activity was demonstrated by several approaches of the FTIR to exhibit the formation of new groups within the polymer structure due to the exposure to UV light. Moreover, the polymer’s weight loss during irradiation and the average molecular weight estimation using its viscosity before and after irradiation were investigated. Furthermore, different techniques were used to study the surface morphology of the PVC before and after irradiation. Field-emission scanning electron microscopy (FESEM) and optical microscope demonstrated that applying Ibuprofen tin complexes keeps the surface of PVC smoother, with fewer cracks and spots after irradiation comparing to the blank PVC. Finally, It seems possible that such synthesized Ibuprofen tin complexes can work as excellent photo-stabilizers of PVC. In particular, complex 1 showed the best results among other stabilizers due to the large conjugation system of the stabilizer.

Membrane Surface Morphology before and after the Reversible Hydrogen Doping of Diffusion Filters

2021 ◽  
Vol 1037 ◽  
pp. 626-631
Author(s):  
Olga V. Akimova ◽  
Irina S. Tereshina ◽  
Tatiana P. Kaminskaya ◽  
Igor A. Karateev
Keyword(s):  
Surface Structure ◽  
Membrane Surface ◽  
Force Microscopy ◽  
Diffusion Filter ◽  
Directional Flow ◽  
Homogenizing Annealing ◽  
Atomic Force ◽  
Before And After ◽  
Membrane Alloy ◽  
Scanning Electron

Atomic force microscopy (АFМ) and high-precision scanning electron microscopy methods were used to study the surface of diffusion filter-membranes of alloy Pd93Y7. The formation of alterations in structure in one of membranes was established as a result from the homogenizing annealing at 900°C for 1 hours. It was found that the reversible doping of the membrane alloy with hydrogen caused the dispersion of the diffusion filter-membranes’ surface structure. Differences in changes by the surface structure are determined during the hydrogenation in directional and non-directional flow of hydrogen.

Poly(Vinyl Chloride) Containing Gynostemma pentaphyllum as a Photostabilizer

2021 ◽  
Vol 1021 ◽  
pp. 251-259
Author(s):  
Zeyad Fadhil ◽  
Hadeel Adil ◽  
Raghda Alsayed ◽  
Mohammed H. Al-Mashhadani ◽  
Ali H. Jawad ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Vinyl Chloride ◽  
Aging Process ◽  
Uv Light ◽  
Polymeric Films ◽  
Gynostemma Pentaphyllum ◽  
Poly Vinyl Chloride ◽  
Electronic Microscope ◽  
Scanning Electron

Novel extracted natural stabilizer for the polymer was investigated in this study. The natural anti-aging was extracted from plants and it is demonstrated that this type of stabilizers are suitable for biodegradable polymers. Gynostemma pentaphyllum (0.01–0.03 wt%) were extracted and added to the poly(vinyl chloride) blend. The achieved polymeric films were exposed to an accelerated UV light aging process for 300 hours at ambient temperature. The efficiency of tested natural stabilizer was linked to blank PVC films. FTIR spectroscopy, weight loss, electronic microscope and scanning electron microscopy were performed. Using small amount of natural stabilizer is significantly beneficial because it does not influence the PVC properties.

Cryogenic atomic force microscopy

1991 ◽  
Vol 49 ◽  
pp. 54-55
Author(s):  
K. A. Fisher ◽  
M. G. L. Gustafsson ◽  
M. B. Shattuck ◽  
J. Clarke
Keyword(s):  
Room Temperature ◽  
Rapid Freezing ◽  
Cryogenic Temperatures ◽  
Soft Or ◽  
Electrically Conductive ◽  
Force Microscopy ◽  
Flexible Molecules ◽  
Advantages And Disadvantages ◽  
Atomic Force ◽  
Chemical Perturbation

The atomic force microscope (AFM) is capable of imaging electrically conductive and non-conductive surfaces at atomic resolution. When used to image biological samples, however, lateral resolution is often limited to nanometer levels, due primarily to AFM tip/sample interactions. Several approaches to immobilize and stabilize soft or flexible molecules for AFM have been examined, notably, tethering coating, and freezing. Although each approach has its advantages and disadvantages, rapid freezing techniques have the special advantage of avoiding chemical perturbation, and minimizing physical disruption of the sample. Scanning with an AFM at cryogenic temperatures has the potential to image frozen biomolecules at high resolution. We have constructed a force microscope capable of operating immersed in liquid n-pentane and have tested its performance at room temperature with carbon and metal-coated samples, and at 143° K with uncoated ferritin and purple membrane (PM).

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