In this work, a method for preparing activated carbon based on cherry kernel shell (AC-CKS) was investigated using two consecutive steps: chemical activation with H2SO4 agent and thermal activation in air. For the first time, AC-CKS product is used for the removal of numerous metal ions such Cr(III), Mn(II), Fe(III), Ni(II), Cu(II), Zn(II), and Pb(II) from water solutions. The AC-CKS was characterized using EA, FTIR, SEM, EDX, and XRF techniques. The AC-CKS obtained by heating at 600 degrees C showed products with higher iodine numbers and invariably micro-size pores compared to those obtained by heating at 55 degrees C and 400 degrees C. The adsorption capacity of AC-CKS600 was tested in the removal of previously mentioned metal ions. The essential parameters affecting the removal of metal ions were studied. The results showed maximum adsorption of 99.0% for Cr(III), 91.7% for Fe(III), 62.0% for Cu(II), 59.3% for Pb(II), 42.0% for Zn(II), 28.0% for Ni(II), and 26.9% for Mn(II). The adsorption data of most metal ions fitted well with Langmuir model. The maximum adsorption capacity followed the sequence: Cr(10.75mg/g)>Fe(10.15mg/g)>Cu(7.58mg/g)>Pb(7.36mg/g)>Zn(6.08mg/g)>Ni(2.83g/g)>Mn(2.29 mg/g). The adsorption kinetics was tested for the pseudo-first order and pseudo-second order. The rate constants of adsorption for all studied metal ions were calculated. Good correlation coefficients (R-2>0.9972) were obtained for the pseudo-second-order kinetic model showing that all metal ions uptake processes followed the pseudo-second-order rate expression. Desorption studies showed the quantitative recovery of metal ions in the range of 89.4% for Pb(II) to 94% for Cr(III). According to the adsorption model applied in this work, AC-CKS600 product could be recommended for the removal of Cr(III), Fe(III), Cu(II), Pb(II), and Zn(II) from aqueous solutions.

Crosslinkable polyethylene compounds (XLPE) produced from different commercial polyethylene polymers are well known in the relevant literature. Both crosslinked high- and low-density polyethylene (HDPE, LDPE) have been investigated in this chapter. It is known that crosslinking induces modifications which focus on the polymer matrix leading to new morphology as well as a new structure allowing 'thermoset' polymer formation with a long-term stability. The crosslinking density is an important factor for the determination of physical properties of various polymer materials. Crosslinked polyethylene can be obtained technically by several chemical and physical processes that affect the morphologies and the structure of the investigating polymer. The resulting network material after the crosslinking process provides the polymer with many important physical and chemical properties. These characterized properties are different from those observed before crosslinking enhancing newly generated physicochemical properties which will be suitable for specific applications according to crosslinking treatment processes. The combination of physical properties, long-term stability, UV resistance and the wide range of structures and morphologies has brought these crosslinked polyethylene products into distinction properties in comparison with other polymers materials. The impact strength; abrasion resistance and environmental stress-cracking resistance are known to increase with the crosslinking which alters XLPE as a suitable material for pipe, tubing and hip arthroplasty applications; while excellent dielectric properties make them useful for high-voltage cables production; besides shrinkage resistance and expansion ratio mark them convenient for foam polymer applications. This chapter provides comprehensive investigation requirement changes in the morphology, structure and properties of XLPE and its applications such as cable insulation, hip arthroplasty, foam, pipes are also discussed.

Carotenoids, a group of phytochemicals, are naturally found in the Plant kingdom, particularly in fruits, vegetables, and algae. There are more than 600 types of carotenoids, some of which are thought to prevent disease, mainly through their antioxidant properties. Carotenoids exhibit several biological and pharmaceutical benefits, such as anti-inflammatory, anti-cancer, and immunity booster properties, particularly as some carotenoids can be converted into vitamin A in the body. However, humans cannot synthesize carotenoids and need to obtain them from their diets or via supplementation. The emerging zoonotic virus severe acute respiratory syndrome coronavirus 2, which causes coronavirus disease 2019 (COVID-19), originated in bats, and was transmitted to humans. COVID-19 continues to cause devastating international health problems worldwide. Therefore, natural preventive therapeutic strategies from bioactive compounds, such as carotenoids, should be appraised for strengthening physiological functions against emerging viruses. This review summarizes the most important carotenoids for human health and enhancing immunity, and their potential role in COVID-19 and its related symptoms. In conclusion, promising roles of carotenoids as treatments against emerging disease and related symptoms are highlighted, most of which have been heavily premeditated in studies conducted on several viral infections, including COVID-19. Further in vitro and in vivo research is required before carotenoids can be considered as potent drugs against such emerging diseases.

A composite consisting of PVC and CaCO3 particles was irradiated with different doses of Gamma rays or electron beam in order to compensate the tensile strength decreases by filler addition. The deployment of irradiation process on the composite improved significantly the tensile strength by about 10–20 % using E-beam and Gamma irradiation at a dose of 250 kGy, respectively. Moreover, the irradiated composite exhibited higher thermal stability. Two thermal dehydrochlorination processes after irradiation have been observed instead of three thermal process before. The calculation of the activation energy of each step showed that initiation step consumed about 60 % of the used energy.

Several types of apricot kernel cultivated in Syria were used in this study in order to clarify differences in their thermal and chemical properties. Chemical and thermal properties were monitored by FTIR, DSC, TGA techniques. Chemical analysis showed that all types of kernel shells from different sources possessed the same structure. However, the thin brown layer (skin) that covers the kernel had some chemical structure differences in comparison to its shell. The decomposition of the kernel shell showed three steps of degradations at 75, 260 and 450 °C related to the removal of water, degradation of cellulose and lignin, respectively. Additional step was observed at ~ 178 °C in particles smaller than 250 µm related to the removal of incorporated water. The kernel skin showed the same thermal properties in degradation with shifting to lower temperature.

Water from a single natural spring filled in PET has been used to examine the sterilization effect of Gamma and E-Beam irradiation on the chemical and microbial quality of water through 6 months of storage under real consumer conditions. Two strategies were adapted in this work; the first was the sterilization of PET empty bottles at 20 kGy dose which were then filled by UV sterilized water. The second was the sterilization of the PET bottled water at the recommended microbial decontamination dose of 5 kGy. Dibutyl phthalate, diethyl phthalate, and dimethyl phthalate concentrations increased significantly during storage under sunlight exposure in comparison with a dark laboratory storage. Nitrite was only presented in PET bottled water that was sterilized by Gamma irradiation and stored in the dark. 5 kGy dose could be considered good for microbial sterilization of PET bottled water and has less impact on leaching of phthalates compounds than 20 kGy dose. Moreover, it could be an emergent method for water decontamination at an industrial level and consequently improve the public health.

Low-density polyethylene (LDPE)/silane compound was subjected to different treatments (thermal ageing, gamma irradiation) to improve its electrical and mechanical properties. Ageing at 80 °C for 90 days showed a decrease in tensile strength/breaking voltage, and an increase in leakage current. In contrast, gamma irradiation of LDPE/silane samples showed an augmentation in tensile strength/breaking voltage and a decrease in leakage current. Also, an improvement in the electrical properties was remarked after the thermal ageing. Irradiation of old polyethylene/silane insulated cables appeared as a good method to enhance its electrical and mechanical properties for further reusing.

Semi-crystalline polyethylene terephthalate (PET) was aged under the effect of natural UV exposure and outdoor temperature during 670 days. The variation in the mechanical and thermal properties beside to the morphology was tracked by applying different analytical techniques, including scanning electron microscopy, infrared spectroscopy, differential scanning calorimetry and wide angle X-ray diffraction, in addition to tensile strength and hardness measurements. It has been confirmed that the ageing process is the results of physical trend only. The aged PET showed a decrease in both tensile strength and strain with an increase in the degree of crystallinity of aged PET samples during the whole period. These changes in crystallinity were examined by various analysis methods: density, calorimetric and infrared spectroscopy. New peaks in FTIR analysis at 1115 and 1090 cm−1 were characterized and proved that this technique is considered to be an easy tool to track the change in the surface crystallinity of aged PET samples directly. The results of this study showed that an augmentation in the degree of crystallinity of outdoor aged PET samples from 18 to 36 %, accompanied with a decrease in tensile strength from 167.9 to 133.7 MPa. Moreover, a good exponential correlation was found between the degree of crystallinity and the mechanical properties of the aged PET.

Polyethylene terephthalate bottles containing natural spring water were used to study the leaching effect of carbonyl compounds after one year storage under real conditions of exposure. Ultraviolet-B and ultraviolet-A spectra of direct sunlight were acquired during the experiment. Leaching of acetone, acetaldehyde, and formaldehyde reached steady state after 210days of outdoor storage, with the following concentrations: 434 +/- 22, 345 +/- 18, and 94 +/- 5 mu g/L, respectively. The increase due to sunlight exposure in comparison with laboratory storage in the dark was around 10%, 16%, and 36%. The leaching process of all three carbonyl compounds was found to follow the first-order kinetics. Photo-degradation of Polyethylene terephthalate bottles and the appearance of carboxyl end-groups were followed by attenuated total reflectance infrared spectra. After 313days of storage under direct sunlight, new peaks appeared in the regions of 1770-1920 cm(-1) and 1685-1490 cm(-1). Cations, anions, total dissolved solids, pH, and conductivity were also measured during the storage period. Additionally, microbiological measurements as well as statistical analyses were also carefully discussed.

ABSTRACTAttenuated total reflection Fourier transform infrared (ATR‐FTIR) and two‐dimensional correlation (2D‐COS) spectroscopies were utilized to probe the structural changes occurring upon sunlight ageing up to 6 months in air atmosphere of both control and sterilized poly(ethylene terephthalate), (PET) bottles.Two dominant reactions were found; namely oxidation of the carbonyl groups and trans to gauche transformation of the ethylene glycole units. Oxidation manifested itself by the progressive development of a distinct band at 1690 cm−1assigned to the antisymmetric stretching of the carbonyl band in an aromatic carboxylic acid. Sterilizing the bottles by E‐beam or Gamma rays prior to ageing reduced the correlation intensity of the band at 1690 cm−1, and led to the presence of higher molecular weight compounds such as terephthalic acid in stored water. The infrared spectroscopy combined with 2D‐COS provides a powerful tool to investigate chemical and stero‐chemical modification of polymers. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44736.

New highly fluorinated poly(arylene ether sulfone)s (FPAES), poly(arylene ether ketone)s (FPAEK), and poly(arylene ether)s with several types of NLO chromophores as pendant groups were obtained by a polycondensation reaction using very mild conditions. The different polymer structures were designed with the objective to investigate the influence of both the polarity of the chromophore and the nature of the tether between the NLO chromophore and the chain. The resulting copolymers have glass transition temperatures (T-g's) varying between 160 and 215 degrees C, and they are stable up to 280 degrees C under nitrogen. Although these copolymers are Soluble in common organic solvents, cyclohexanone gave the best film quality and was used for the film preparation. After optimization of the poling conditions, the in situ second harmonic generation (SHG) measurements gave nonresonant Values of the second-order susceptibilities d(33) ranging from 2 to 8 pm/V, and the SHG signals of the poled polymer films were found to be thermally stable below 130 degrees C. Although being comparable with the values obtained for similar polymers and chromophores in the literature, d(33) are smaller than those obtained for more conventional NLO polymers like PMMA-Disperse Red One (PMMA-DR1), which was taken as a reference. An unusual drop of the SHG signal during cooling was found in the thermally assisted orientation process. This drop occurred at a characteristic temperature below T-g. In this relaxation process which has never been observed, intra- and interchain dipolar interactions are shown to play,in important role, which is amplified in the case of chromophores which have their donor group embedded in the main chain, connected by two rigid tethers.

New fluorinated poly(arylene ether sulfone)s (FPAES) and poly (arylene ether ketone)s (FPAEK) with two types of NLO chromophores as pendant groups were obtained by a polycondensation reaction carried out using very mild reaction conditions. The glass transition temperature (Tg) of these copolymers is between 168 and 190°C. The SHG intensity was measured during thermal corona poling : the dipole orientation starts at 100°C, and reaches a maximum at 160°C, which is lower than Tg. During cooling of the film under the applied electric field, we observed an unusual drop of the SHG intensity starting at 120°C and reaching 70 % of the maximum value. The physical origin of this drop has been investigated and is possibly attributable to a secondary phase transition of the copolymers. Despite this decrease, d33 coefficients measured after poling vary between 2 and 15 pm/V at 1907 nm fundamental wavelength, depending on the first hyperpolarisability of the NLO chromophore. The dipole orientation of all these copolymers is very stable provided the temperature of the films is kept below the temperature threshold of 120 °C, which is below the Tg of the polymers.

Highly fluorinated poly(arylene ether ketone) s and poly(arylene ether sulfone) s containing efficient second order NLO chromophores covalently linked as side-chain groups were synthesized using a polycondensation reaction. The glass transition temperatures of these copolymers were found between 163(circle)C and 197(circle)C. Second Harmonic Generation (SHG) coefficients (d(33)) of the poled polymer films (corona poling, voltage 5 kV) reached values of about 14pm.V-1 at 1907 nm fundamental wavelength. No appreciable decay of the SHG signal was observed below 130(circle)C. These new copolymers allow a compromise to be reached between high transparency at telecommunication wavelengths (associated with the replacement of most of CH bonds by CF bonds), good SHG efficiency and acceptable thermal stability of the dipole orientation.