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Highly pure cellulosic polymers obtained from waste lignocellulose offer great potential for designing novel materials in the concept of biorefinery. In this work, alpha-cellulose and nanocrystalline cellulose were isolated from the date palm trunk mesh (DPTM) through a series of physicochemical treatments. Supercritical carbon dioxide treatment was used to remove soluble extractives, and concentrated alkali pretreatment was used to eliminate the lignin portion selectively to obtain alpha-cellulose in approximately 94% yield. Further treatments of this cellulose yielded nanocrystalline cellulose. The structure–property relationship studies were carried out by characterizing the obtained polymers by various standard methods and analytical techniques such as Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), energy dispersive X-ray diffraction (EDX-XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Almost 65% yield of pure cellulose was achieved, out of which 94% is the alpha-cellulose. This cellulose shows good thermal stability and crystallinity. The microscopic analysis of the nanocellulose showed a heterogeneous mix of irregular-shaped particles with a size range of 20–60 nm. The percentage crystallinity of alpha-cellulose and nanocellulose was found to be 68.9 and 71.8, respectively. Thus, this study shows that, this DPTM-based low-cost waste biomass can be a potential source to obtain cellulose and nano-cellulose.
Hamid Shaikh; Arfat Anis; Anesh Poulose; Saeed Al-Zahrani; Niyaz Madhar; Abdullah Alhamidi; Mohammad Alam. Isolation and Characterization of Alpha and Nanocrystalline Cellulose from Date Palm (Phoenix dactylifera L.) Trunk Mesh. Polymers 2021, 13, 1893 .
AMA StyleHamid Shaikh, Arfat Anis, Anesh Poulose, Saeed Al-Zahrani, Niyaz Madhar, Abdullah Alhamidi, Mohammad Alam. Isolation and Characterization of Alpha and Nanocrystalline Cellulose from Date Palm (Phoenix dactylifera L.) Trunk Mesh. Polymers. 2021; 13 (11):1893.
Chicago/Turabian StyleHamid Shaikh; Arfat Anis; Anesh Poulose; Saeed Al-Zahrani; Niyaz Madhar; Abdullah Alhamidi; Mohammad Alam. 2021. "Isolation and Characterization of Alpha and Nanocrystalline Cellulose from Date Palm (Phoenix dactylifera L.) Trunk Mesh." Polymers 13, no. 11: 1893.
Chromium oxide supported on mesoporous organo-silica (MOS) was synthesized with different Cr loading by an incipient method. The catalytic performance of a Cr(x)/MOS catalyst for CO2-based ethane dehydrogenation was investigated. The synthesized catalysts were characterized by XRD, BET, TEM, SEM, XPS, FTIR, and UV–Vis DR measurements. The textural properties of the prepared samples showed that the mesoporous nature of MOS sample was not disturbed by chromium impregnation. Among the prepared samples, Cr(8)/MOS catalyst exhibited good distribution of chromium species along with superior concentration of Cr6+ and the highest recorded Cr6+/Cr3+ ratio. The results revealed that the superior catalytic performance was reached at Cr(8)/MOS, with 50.4% and 90.1% of ethane conversion and ethylene selectivity, respectively. The catalytic activity decreased slowly over reaction time; it declined approximately 22% after 10 h of stream operation. The roles of CO2-based ethane dehydrogenation were also studied, where carbon dioxide can be a source of lattice oxygen and as a hydrogen consumer in reverse water–gas shift (RWGS) reaction. The effect of various catalytic factors, such as catalytic temperature, reaction time, space gas velocity, and CO2 partial pressure on the conversion of ethane, yield, and selectivity to ethylene, were investigated as well.
Abdulrhman Al-Awadi; Ahmed El-Toni; Joselito Labis; Aslam Khan; Hamid Ghaithan; Attiyah Al-Zahrani; Ahmed Abasaeed; Saeed Al-Zahrani. Mesoporous Organo-Silica Supported Chromium Oxide Catalyst for Oxidative Dehydrogenation of Ethane to Ethylene with CO2. Catalysts 2021, 11, 642 .
AMA StyleAbdulrhman Al-Awadi, Ahmed El-Toni, Joselito Labis, Aslam Khan, Hamid Ghaithan, Attiyah Al-Zahrani, Ahmed Abasaeed, Saeed Al-Zahrani. Mesoporous Organo-Silica Supported Chromium Oxide Catalyst for Oxidative Dehydrogenation of Ethane to Ethylene with CO2. Catalysts. 2021; 11 (5):642.
Chicago/Turabian StyleAbdulrhman Al-Awadi; Ahmed El-Toni; Joselito Labis; Aslam Khan; Hamid Ghaithan; Attiyah Al-Zahrani; Ahmed Abasaeed; Saeed Al-Zahrani. 2021. "Mesoporous Organo-Silica Supported Chromium Oxide Catalyst for Oxidative Dehydrogenation of Ethane to Ethylene with CO2." Catalysts 11, no. 5: 642.
Synergistic formulations were developed with nano-pigments, and their effects on the mechanical properties on steel substrates and structures were evaluated. This paper provides a complete analysis of the epoxy coating, focusing on the incorporation of nano-pigments and their synergistic effects in obtaining higher mechanical properties. This study reports the preparation of epoxy nano-silica composites, their characterization, and the development of coatings based on nano-silica and ZnO particles. In this composite, epoxy resin was incorporated with SiO2 as the main pigment and ZnO as a synergistic pigment to achieve high-performance epoxy coatings for multiple applications. The mechanical properties of these coatings (ESZ1–ESZ3) were evaluated by nanoindentation, and were used to measure the enhanced durability of nanocomposite coatings developed with synergistic formulations with different types of nanoparticles. Their performance was evaluated before and after exposure to a 3.5% NaCl solution to examine the changes of hardness and elastic modulus. The results showed that the nanoindentation technique, in conjunction with Fourier transform infrared spectroscopy and X-ray diffraction, could examine the durability and predict the service life of nanocomposite coatings. A correlation was observed between the modulus and hardness before and after exposing epoxy composite coatings (ESZ1–ESZ3) to a 3.5% NaCl solution.
Mohammad Alam; Ubair Samad; Arfat Anis; Manawwer Alam; Mohd Ubaidullah; Saeed Al-Zahrani. Effects of SiO2 and ZnO Nanoparticles on Epoxy Coatings and Its Performance Investigation Using Thermal and Nanoindentation Technique. Polymers 2021, 13, 1490 .
AMA StyleMohammad Alam, Ubair Samad, Arfat Anis, Manawwer Alam, Mohd Ubaidullah, Saeed Al-Zahrani. Effects of SiO2 and ZnO Nanoparticles on Epoxy Coatings and Its Performance Investigation Using Thermal and Nanoindentation Technique. Polymers. 2021; 13 (9):1490.
Chicago/Turabian StyleMohammad Alam; Ubair Samad; Arfat Anis; Manawwer Alam; Mohd Ubaidullah; Saeed Al-Zahrani. 2021. "Effects of SiO2 and ZnO Nanoparticles on Epoxy Coatings and Its Performance Investigation Using Thermal and Nanoindentation Technique." Polymers 13, no. 9: 1490.
A tremendous potential has been observed in the designing of long afterglow materials for sensing, bioimaging, and encryption applications. In this study, two different strontium aluminate-based luminescent materials; SrAl2O4: Eu, Dy (S1), and Sr4Al14O25: Eu, Dy (S2) were melt-mixed with polypropylene (PP) matrix, and the phosphorescence properties were evaluated. After excitation at 320 nm, the PP/S1 composite exhibited a green emission and the PP/S2 generated a blue emission at 520 nm and 495 nm, respectively. The emission spectra intensity increased by increasing the content of these luminescent fillers. The attenuated total reflection-Fourier transform infrared (ATR-FTIR) experiments show that no chemical reaction occurred during the melt-mixing process. The differential scanning calorimetry (DSC) results revealed that the total crystallinity of the composites reduced by increasing the amount of the fillers; however, no changes in the temperature of melting (Tm) and crystallization (Tc) of PP were observed. Both fillers improved the impact strength of the composites, but the tensile strength (TS) and modulus (TM) decreased. Poly (ethylene glycol) dimethyl ether (P) plasticizer was used to improve the filler-matrix interaction and its dispersion; nevertheless, it adversely affected the intensity of the luminescence emissions.
Anesh Poulose; Arfat Anis; Hamid Shaikh; Abdullah Alhamidi; Nadavala Siva Kumar; Ahmed Elnour; Saeed Al-Zahrani. Strontium Aluminate-Based Long Afterglow PP Composites: Phosphorescence, Thermal, and Mechanical Characteristics. Polymers 2021, 13, 1373 .
AMA StyleAnesh Poulose, Arfat Anis, Hamid Shaikh, Abdullah Alhamidi, Nadavala Siva Kumar, Ahmed Elnour, Saeed Al-Zahrani. Strontium Aluminate-Based Long Afterglow PP Composites: Phosphorescence, Thermal, and Mechanical Characteristics. Polymers. 2021; 13 (9):1373.
Chicago/Turabian StyleAnesh Poulose; Arfat Anis; Hamid Shaikh; Abdullah Alhamidi; Nadavala Siva Kumar; Ahmed Elnour; Saeed Al-Zahrani. 2021. "Strontium Aluminate-Based Long Afterglow PP Composites: Phosphorescence, Thermal, and Mechanical Characteristics." Polymers 13, no. 9: 1373.
The crystallization behavior of polyolefins continues to gain much attention for the prediction of suitable processing conditions. This study aims to understand the influence of biochar (BC) particles on the crystallization behavior of the selected semi-crystalline polypropylene (PP). For this purpose, BC samples were prepared from waste biomass at various pyrolysis temperature. The prepared BC samples were used to fabricate PP composites via melt processing technique. The crystallization behavior of these composites was studied by differential scanning calorimetry (DSC) calorimetry and validated using Avrami analysis in a non-isothermal conditions. It was observed that BC particles act as nucleating agents and accelerate the overall rate of crystallization. Avrami theory analysis indicated that the addition of BC particles provides polypropylene (PP) composites with a higher crystallization rate, i.e. about one order of magnitude higher than the neat PP. The results of the TGA analysis showed that the BC particles enhanced the thermal stability of the BC/PP composites, and is up to 80 °C higher than the neat PP sample.
Abdulaziz A. Alghyamah; Ahmed Yagoub Elnour; Hamid Shaikh; Sajjad Haider; Anesh Manjaly Poulose; S.M. Al-Zahrani; Waheed A. Almasry; Soo Young Park. Biochar/polypropylene composites: A study on the effect of pyrolysis temperature on crystallization kinetics, crystalline structure, and thermal stability. Journal of King Saud University - Science 2021, 33, 101409 .
AMA StyleAbdulaziz A. Alghyamah, Ahmed Yagoub Elnour, Hamid Shaikh, Sajjad Haider, Anesh Manjaly Poulose, S.M. Al-Zahrani, Waheed A. Almasry, Soo Young Park. Biochar/polypropylene composites: A study on the effect of pyrolysis temperature on crystallization kinetics, crystalline structure, and thermal stability. Journal of King Saud University - Science. 2021; 33 (4):101409.
Chicago/Turabian StyleAbdulaziz A. Alghyamah; Ahmed Yagoub Elnour; Hamid Shaikh; Sajjad Haider; Anesh Manjaly Poulose; S.M. Al-Zahrani; Waheed A. Almasry; Soo Young Park. 2021. "Biochar/polypropylene composites: A study on the effect of pyrolysis temperature on crystallization kinetics, crystalline structure, and thermal stability." Journal of King Saud University - Science 33, no. 4: 101409.
The wastage of food products is a major challenge for the food industry. In this regard, the use of edible films and coatings have gained much attention due to their ability to prevent the spoilage of the food products during handling, transport, and storage. This has effectively helped in extending the shelf-life of the food products. Among the various polymers, polysaccharides have been explored to develop edible films and coatings in the last decade. Such polymeric systems have shown great promise in microbial food safety applications. The inclusion of essential oils (EOs) within the polysaccharide matrices has further improved the functional properties of the edible films and coatings. The current review will discuss the different types of polysaccharides, EOs, methods of preparing edible films and coatings, and the characterization methods for the EO-loaded polysaccharide films. The mechanism of the antimicrobial activity of the EOs has also been discussed in brief.
Arfat Anis; Kunal Pal; Saeed M. Al-Zahrani. Essential Oil-Containing Polysaccharide-Based Edible Films and Coatings for Food Security Applications. Polymers 2021, 13, 575 .
AMA StyleArfat Anis, Kunal Pal, Saeed M. Al-Zahrani. Essential Oil-Containing Polysaccharide-Based Edible Films and Coatings for Food Security Applications. Polymers. 2021; 13 (4):575.
Chicago/Turabian StyleArfat Anis; Kunal Pal; Saeed M. Al-Zahrani. 2021. "Essential Oil-Containing Polysaccharide-Based Edible Films and Coatings for Food Security Applications." Polymers 13, no. 4: 575.
Metal-plastic composites have the potential to combine enhanced electrical and thermal conductivity with a lower density than a pure metal. The drawback has often been brittleness and low impact resistance caused by weak adhesion between the metal filler and the plastic. Based on our observation that aluminum foil sticks very strongly to poly(ethylene terephthalate) (PET) if it is used as a backing during compression moulding, this work set out to explore PET filled with a micro and a nano aluminum (Al) powder. In line with other composites using filler particles with low aspect-ratio, the tensile modulus increased somewhat with loading. However, unlike most particle composites, the strength did not decrease and most surprisingly, the Izod impact resistance increased, and in fact more than doubled with certain compositions. Thus, the Al particles acted as a toughening agent without decreasing the modulus and strength. This would be the first case where addition of a metal powder to a plastic increased the modulus and impact resistance simultaneously. The Al particles also acted as nucleating agents but it was not sufficient to make PET crystallize as fast as the injection moulding polyester, poly(butylene terephthalate) (PBT).
Arfat Anis; Ahmed Yagoub Elnour; Mohammad Asif Alam; Saeed M. Al-Zahrani; Fayez Alfayez; Zahir Bashir. Aluminum-Filled Amorphous-PET, a Composite Showing Simultaneous Increase in Modulus and Impact Resistance. Polymers 2020, 12, 2038 .
AMA StyleArfat Anis, Ahmed Yagoub Elnour, Mohammad Asif Alam, Saeed M. Al-Zahrani, Fayez Alfayez, Zahir Bashir. Aluminum-Filled Amorphous-PET, a Composite Showing Simultaneous Increase in Modulus and Impact Resistance. Polymers. 2020; 12 (9):2038.
Chicago/Turabian StyleArfat Anis; Ahmed Yagoub Elnour; Mohammad Asif Alam; Saeed M. Al-Zahrani; Fayez Alfayez; Zahir Bashir. 2020. "Aluminum-Filled Amorphous-PET, a Composite Showing Simultaneous Increase in Modulus and Impact Resistance." Polymers 12, no. 9: 2038.
This paper presents the studies of the development of a high-performance epoxy coating for steel substrates. To this end, it investigated the synergistic effect of incorporating zinc oxide (ZnO) nanoparticles into nanosilica containing epoxy formulations. The mechanical properties of the epoxy coating formulations were improved by modifying the surfaces of the silica nanoparticles (5 wt.%) with 3-glycidoxypropyl trimethoxysilane, which ensured their dispersal through the material. Next, the ZnO nanoparticles (1, 2, or 3 wt.%) were incorporated to improve the corrosion performance of the formulations. The anticorrosive properties of the coatings were examined by electrochemical impedance spectroscopy (EIS) of coated mild steel specimens immersed in 3.5% NaCl solution over different time intervals (1 h to 30 days). Incorporation of the ZnO nanoparticles and the nanosilica into the coating formulation improved the corrosion resistance of the epoxy coating even after long-term exposure to saline test solutions. Finally, to evaluate how the nanoparticles affected the chemical and morphological properties of the prepared coatings, the coatings were characterized by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD).
Ubair Abdus Samad; Mohammad Asif Alam; Arfat Anis; El-Sayed M. Sherif; Sulaiman I. Al-Mayman; Saeed M. Al-Zahrani. Effect of Incorporated ZnO Nanoparticles on the Corrosion Performance of SiO2 Nanoparticle-Based Mechanically Robust Epoxy Coatings. Materials 2020, 13, 3767 .
AMA StyleUbair Abdus Samad, Mohammad Asif Alam, Arfat Anis, El-Sayed M. Sherif, Sulaiman I. Al-Mayman, Saeed M. Al-Zahrani. Effect of Incorporated ZnO Nanoparticles on the Corrosion Performance of SiO2 Nanoparticle-Based Mechanically Robust Epoxy Coatings. Materials. 2020; 13 (17):3767.
Chicago/Turabian StyleUbair Abdus Samad; Mohammad Asif Alam; Arfat Anis; El-Sayed M. Sherif; Sulaiman I. Al-Mayman; Saeed M. Al-Zahrani. 2020. "Effect of Incorporated ZnO Nanoparticles on the Corrosion Performance of SiO2 Nanoparticle-Based Mechanically Robust Epoxy Coatings." Materials 13, no. 17: 3767.
Ti modification of mesoporous silica support has been reported as an effective way to enhance Cr–Ti–Si interactions that, in turn, impact the catalytic dehydrogenation of ethane with CO2. However, such modification necessitates a repeated, time-consuming and tedious process. In this work, a simple, fast and facile approach has been utilized to synthesize chromium-oxide-loaded titania–silica mesoporous nanocomposites. A series of Cr(y)/Ti(x)–Si mesoporous nanocomposite catalysts with varying Ti and Cr contents were prepared and tested in the dehydrogenation of ethane with carbon dioxide. The as-synthesized catalysts were characterized by XRD, TEM, SEM, BET, UV–Vis–DR, XPS and H2–TPR techniques. The effect of titanium content, as well as chromium loading on the performance of the prepared Cr(y)/Ti(x)–Si catalysts, was investigated. It was found that 2.2 and 8 wt % are the optimum titanium and chromium contents in the synthesized catalysts for obtaining the highest catalytic activity. The superior catalytic performance of the Cr(8)/Ti(2.2)–Si catalyst can be attributed to a higher dispersion of the Cr species, as well as a higher content of the redox Cr species on the surface of the Cr/Ti–Si catalyst. The results showed that the Cr(8)/Ti(2.2)–Si catalyst efficiently dehydrogenated C2H6 in the presence of CO2 giving a 52.3% ethane conversion and 48.0% ethylene yield at 700 °C reaction temperature.
Abdulrhman S. Al-Awadi; Ahmed Mohamed El-Toni; Saeed M. Al-Zahrani; Ahmed E. Abasaeed; Aslam Khan. Synthesis, Characterization and Catalytic Evaluation of Chromium Oxide Deposited on Titania–Silica Mesoporous Nanocomposite for the Ethane Dehydrogenation with CO2. Crystals 2020, 10, 322 .
AMA StyleAbdulrhman S. Al-Awadi, Ahmed Mohamed El-Toni, Saeed M. Al-Zahrani, Ahmed E. Abasaeed, Aslam Khan. Synthesis, Characterization and Catalytic Evaluation of Chromium Oxide Deposited on Titania–Silica Mesoporous Nanocomposite for the Ethane Dehydrogenation with CO2. Crystals. 2020; 10 (4):322.
Chicago/Turabian StyleAbdulrhman S. Al-Awadi; Ahmed Mohamed El-Toni; Saeed M. Al-Zahrani; Ahmed E. Abasaeed; Aslam Khan. 2020. "Synthesis, Characterization and Catalytic Evaluation of Chromium Oxide Deposited on Titania–Silica Mesoporous Nanocomposite for the Ethane Dehydrogenation with CO2." Crystals 10, no. 4: 322.
Epoxy formulations containing 1%, 3%, and 5% SiO2 nanoparticles (SNPs) were produced and applied to mild steel substrates in order to improve their thermal, nanomechanical, and abrasion resistance. Field emission scanning electron microscopy (FE-SEM) was used to analyze the dispersion of nanoparticles in the final coating samples, and Energy-dispersive X-ray spectroscopy (EDX) was used to confirm the presence of nanoparticles. Thermogravimetric analysis (TGA) was employed to measure the thermal resistance of the prepared coatings. Conventional techniques were used to measure the impact and scratch resistance. For nanomechanical testing, nanoindentation was performed using a Berkovich-type indenter. Using a taber abraser, the abrasion properties of the coatings were measured. The FE-SEM images indicated good dispersion of the nanoparticles at all three different loading levels. The scratch, impact, and hardness of coatings improved with the addition of the SNPs. Nanomechanical properties, such as hardness and elastic modulus, improved when compared to the unmodified coatings. The thermal and abrasion resistances of the coatings improved with the increase in the SNPs content of the coatings. The highest mechanical, thermal, and abrasion properties were obtained for the coatings with 5% SNP content.
Mohammad Asif Alam; Ubair Abdus Samad; Manawwer Alam; Arfat Anis; Saeed M. Al-Zahrani. Enhancement in Nanomechanical, Thermal, and Abrasion Properties of SiO2 Nanoparticle-Modified Epoxy Coatings. Coatings 2020, 10, 310 .
AMA StyleMohammad Asif Alam, Ubair Abdus Samad, Manawwer Alam, Arfat Anis, Saeed M. Al-Zahrani. Enhancement in Nanomechanical, Thermal, and Abrasion Properties of SiO2 Nanoparticle-Modified Epoxy Coatings. Coatings. 2020; 10 (4):310.
Chicago/Turabian StyleMohammad Asif Alam; Ubair Abdus Samad; Manawwer Alam; Arfat Anis; Saeed M. Al-Zahrani. 2020. "Enhancement in Nanomechanical, Thermal, and Abrasion Properties of SiO2 Nanoparticle-Modified Epoxy Coatings." Coatings 10, no. 4: 310.
Epoxy coating formulations containing 1%, 3%, and 5% SiO2 nanoparticles were produced and applied on a mild steel substrate to achieve the objective of high performance corrosion resistance. The electrochemical impedance spectroscopy (EIS) technique was employed to measure the anticorrosive properties of coatings. The corrosion tests were performed by exposing the coated samples in a solution of 3.5% NaCl for different periods of time, varied from 1 h and up to 30 days. Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) analyses revealed the presence of nanoparticles in the final cured samples. Establishing the incorporation of the nanoparticles in the coating formulations was confirmed by employing both of XRD and FT-IR techniques. The FT-IR spectra have proved to be satisfactory indicating that there was a complete reaction between the epoxy resin with the hardener. EIS measurements confirmed that the presence and the increase of SiO2 nanoparticles greatly improved the corrosion resistance of the epoxy coating. The highest corrosion resistance for the coatings was obtained for the formulation with 5% SiO2 nanoparticles content, particularly with prolonging the immersion time to 30 days.
Mohammad Asif Alam; Ubair Abdus Samad; El-Sayed M. Sherif; Anesh Manjaly Poulose; Jabair Ali Mohammed; Nabeel Alharthi; Saeed M. Al-Zahrani. Influence of SiO2 Content and Exposure Periods on the Anticorrosion Behavior of Epoxy Nanocomposite Coatings. Coatings 2020, 10, 118 .
AMA StyleMohammad Asif Alam, Ubair Abdus Samad, El-Sayed M. Sherif, Anesh Manjaly Poulose, Jabair Ali Mohammed, Nabeel Alharthi, Saeed M. Al-Zahrani. Influence of SiO2 Content and Exposure Periods on the Anticorrosion Behavior of Epoxy Nanocomposite Coatings. Coatings. 2020; 10 (2):118.
Chicago/Turabian StyleMohammad Asif Alam; Ubair Abdus Samad; El-Sayed M. Sherif; Anesh Manjaly Poulose; Jabair Ali Mohammed; Nabeel Alharthi; Saeed M. Al-Zahrani. 2020. "Influence of SiO2 Content and Exposure Periods on the Anticorrosion Behavior of Epoxy Nanocomposite Coatings." Coatings 10, no. 2: 118.
A series of large-pore mesoporous silica (LPMS)-supported CrOx catalysts were synthesized by hydrothermal and impregnation methods and tested for ethane dehydrogenation in the presence of CO2 as an oxidant. To assess the effect of hydrothermal temperature treatment on the characteristics of LPMS support, different hydrothermal temperatures (100–160 °C) were studied and optimized. The optimum support was then loaded with different amounts of chromium (0, 2, 4, 8, and 11 wt % Cr). The obtained catalysts were characterized by different techniques such as XRD, BET, TEM, SEM, XPS, FTIR, and diffuse reflectance UV-Vis spectroscopy. The characterization results indicated that the sample hydrothermally treated at 130 °C exhibited the highest pore volume, a narrow pore size distribution, and a moderate BET surface area. Chromium species with various oxidation states including Cr3+, Cr6+, and α-Cr2O3 were detected in all synthesized Cr(y)/LPMS-130 catalysts. A lower Cr content resulted in the formation of Cr6+, whereas a higher Cr content dominated the α-Cr2O3 on the surface of the catalyst. Among the synthesized catalysts, the Cr(4)/LPMS-130 catalyst showed the highest Cr6+/Cr3+ ratio, indicating a good dispersion of chromium species along with a fine particle size. The ethane conversion and ethylene selectivity were 50.5 and 91.1% for Cr(4)/LPMS-130, respectively. Carbon dioxide was believed to supply enough lattice oxygen to maintain the Cr species at a higher oxidation state and to consume the hydrogen resulting from ethane cracking by a reverse water gas shift reaction.
Abdulrhman S. Al-Awadi; Saeed M. Al-Zahrani; Ahmed Mohamed El-Toni; Ahmed E. Abasaeed. Dehydrogenation of Ethane to Ethylene by CO2 over Highly Dispersed Cr on Large-Pore Mesoporous Silica Catalysts. Catalysts 2020, 10, 97 .
AMA StyleAbdulrhman S. Al-Awadi, Saeed M. Al-Zahrani, Ahmed Mohamed El-Toni, Ahmed E. Abasaeed. Dehydrogenation of Ethane to Ethylene by CO2 over Highly Dispersed Cr on Large-Pore Mesoporous Silica Catalysts. Catalysts. 2020; 10 (1):97.
Chicago/Turabian StyleAbdulrhman S. Al-Awadi; Saeed M. Al-Zahrani; Ahmed Mohamed El-Toni; Ahmed E. Abasaeed. 2020. "Dehydrogenation of Ethane to Ethylene by CO2 over Highly Dispersed Cr on Large-Pore Mesoporous Silica Catalysts." Catalysts 10, no. 1: 97.
Oxidative dehydrogenation of alkanes to alkenes by a mild oxidant such as carbon dioxide is an active area of research. A series of MCM41-supported bimetallic oxide catalysts containing chromium oxide in addition to metal oxides (Ce, Co, Zn, V, Nb, and Mo) has been prepared. The binary catalysts have Cr metal oxide incorporated into MCM41 structure while the other oxides are either incorporated with Cr or impregnated on the MCM41 surface. The synthesized catalysts were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N2 sorption, scanning electron microscopy (SEM), hydrogen temperature programmed reduction (H2-TPR), and Diffuse reflectance UV–vis spectroscopy (DRS). The catalytic activity of Cr(4)-M(4)/MCM-41 catalysts in the dehydrogenation of ethane with CO2 was investigated. The textural properties of the synthesized samples showed that the addition of the bimetallic oxides did not disturb the mesoporous structure of MCM41 and the prepared catalysts exhibited a high BET surface area; however, the lowest surface area was recorded for Cr(4)-Mo(4)/MCM41 catalyst at 701 m2/g. Among the prepared catalysts, H2-TPR profile of Cr(4)-Ce(4)/MCM41 revealed the increase in the concentration of Cr6+ species which interacted with the framework of siliceous support. On the other hand, H2-TPR profiles of Cr(4)-Co(4)/MCM41 showed wide reduction peaks centered at 400 °C which is ascribed to reduction of Cr6+ to Cr3+ species and Co3O4 to metallic Co. At the same time, Cr(4)-Mo(4)/MCM41 and Cr(4)-V(4)/MCM41 exhibited higher temperature reduction peaks, indicating these two catalysts require higher activation temperatures. The synergy between the Cr with Zn or Nb metals reduced the concentration of Cr6+ species which is reflected in their catalytic performance. Cr(4)-Ce(4)/MCM41 recorded the highest catalytic activity toward ethylene production where the ethane conversion and ethylene yield were 37.9% and 35.1%, respectively.
Abdulrhman S. Al-Awadi; Ahmed Mohamed El-Toni; Mansour Alhoshan; Aslam Khan; Muhammad Ali Shar; Ahmed E. Abasaeed; Saeed M. Al-Zahrani. Synergetic Impact of Secondary Metal Oxides of Cr-M/MCM41 Catalyst Nanoparticles for Ethane Oxidative Dehydrogenation Using Carbon Dioxide. Crystals 2019, 10, 7 .
AMA StyleAbdulrhman S. Al-Awadi, Ahmed Mohamed El-Toni, Mansour Alhoshan, Aslam Khan, Muhammad Ali Shar, Ahmed E. Abasaeed, Saeed M. Al-Zahrani. Synergetic Impact of Secondary Metal Oxides of Cr-M/MCM41 Catalyst Nanoparticles for Ethane Oxidative Dehydrogenation Using Carbon Dioxide. Crystals. 2019; 10 (1):7.
Chicago/Turabian StyleAbdulrhman S. Al-Awadi; Ahmed Mohamed El-Toni; Mansour Alhoshan; Aslam Khan; Muhammad Ali Shar; Ahmed E. Abasaeed; Saeed M. Al-Zahrani. 2019. "Synergetic Impact of Secondary Metal Oxides of Cr-M/MCM41 Catalyst Nanoparticles for Ethane Oxidative Dehydrogenation Using Carbon Dioxide." Crystals 10, no. 1: 7.
In this study, two formulae (F1 and F2) of epoxy/2pack coatings incorporated with polypyrrole (PPy)-conducting polymer were produced from bisphenol-A type of epoxy resin (DGEBA) with the addition of Ag and ZnO nanoparticles. The synergism effect of Ag and ZnO nanoparticles on the mechanical and corrosion resistance properties was reported. The curing agent 2,4,6-tris (dimethylaminomethyl) phenol (ARADUR 3282-BD) was used under optimized stoichiometry values. The nanoparticles ratio in different wt.% were first dispersed in solvent by the sonication process and then added to epoxy/PPy composition. All the coated steel panels were cured at room temperature in a controlled dust free environment for 7 days in order to obtain a hard and intact coating. The dispersion of nano-size ZnO and Ag pigments was investigated using scanning electron microscopy (SEM) and its composition through an energy dispersive X-ray (EDX) technique. Conventional techniques and nano-indentation were also performed to observe the effect of ZnO and Ag synergism content on the hardness and modulus of elasticity at nano scale. The corrosion behavior of the coated samples was investigated at room temperature in 3.5% NaCl solution using electrochemical impedance spectroscopy (EIS). The synergism effect of nanoparticles along with PPy resulted in an enhancement of mechanical and corrosion-resistant properties.
Ubair Abdus Samad; Mohammad Asif Alam; El-Sayed M. Sherif; Manawwar Alam; Hamid Shaikh; Nabeel H. Alharthi; Saeed M. Al-Zahrani. Synergistic Effect of Ag and ZnO Nanoparticles on Polypyrrole-Incorporated Epoxy/2pack Coatings and Their Corrosion Performances in Chloride Solutions. Coatings 2019, 9, 287 .
AMA StyleUbair Abdus Samad, Mohammad Asif Alam, El-Sayed M. Sherif, Manawwar Alam, Hamid Shaikh, Nabeel H. Alharthi, Saeed M. Al-Zahrani. Synergistic Effect of Ag and ZnO Nanoparticles on Polypyrrole-Incorporated Epoxy/2pack Coatings and Their Corrosion Performances in Chloride Solutions. Coatings. 2019; 9 (5):287.
Chicago/Turabian StyleUbair Abdus Samad; Mohammad Asif Alam; El-Sayed M. Sherif; Manawwar Alam; Hamid Shaikh; Nabeel H. Alharthi; Saeed M. Al-Zahrani. 2019. "Synergistic Effect of Ag and ZnO Nanoparticles on Polypyrrole-Incorporated Epoxy/2pack Coatings and Their Corrosion Performances in Chloride Solutions." Coatings 9, no. 5: 287.
Environmental management through effective utilization of biowastes has been a topic of intensive research in recent years. This study examines the effect of pyrolysis temperature on the physical and morphological characteristic of biochar (BC) derived from lignocellulosic wastes. The biochar was prepared by pyrolysing date palm biomass at various temperatures, i.e., 300, 400, 500, 600, and 700 °C. These pyrolysed biochars were then characterized for their carbon content, mineral compositions, chemical functionalities, and morphological structures, for understanding their physicochemical characteristics and microstructural evolution. It was revealed that the pyrolytic condition plays a key role in the formation of biochar microstructure. These biochar samples were then utilized without any further treatments/purifications for their practical application as reinforcement materials for polymer composites. They were blended with a polypropylene matrix by a melt mixing technique followed by injection molding process. The type of biochar was found to significantly affect the composites properties. Differences in microstructure, surface chemistry, and chemical compositions of BCs were observed to be determining factors affecting the compatibility and thermomechanical properties of resulted composites.
Ahmed Y. Elnour; Abdulaziz A. Alghyamah; Hamid M. Shaikh; Anesh M. Poulose; Saeed M. Al-Zahrani; Arfat Anis; Mohammad I. Al-Wabel. Effect of Pyrolysis Temperature on Biochar Microstructural Evolution, Physicochemical Characteristics, and Its Influence on Biochar/Polypropylene Composites. Applied Sciences 2019, 9, 1149 .
AMA StyleAhmed Y. Elnour, Abdulaziz A. Alghyamah, Hamid M. Shaikh, Anesh M. Poulose, Saeed M. Al-Zahrani, Arfat Anis, Mohammad I. Al-Wabel. Effect of Pyrolysis Temperature on Biochar Microstructural Evolution, Physicochemical Characteristics, and Its Influence on Biochar/Polypropylene Composites. Applied Sciences. 2019; 9 (6):1149.
Chicago/Turabian StyleAhmed Y. Elnour; Abdulaziz A. Alghyamah; Hamid M. Shaikh; Anesh M. Poulose; Saeed M. Al-Zahrani; Arfat Anis; Mohammad I. Al-Wabel. 2019. "Effect of Pyrolysis Temperature on Biochar Microstructural Evolution, Physicochemical Characteristics, and Its Influence on Biochar/Polypropylene Composites." Applied Sciences 9, no. 6: 1149.
In this work, epoxy/2pack coatings containing polyaniline (PANI) in combination with Ag and ZnO nanoparticles have been synthesized. The nanoparticles were incorporated with bisphenol-A diglycidyl ether epoxy resin and polyamino-amide. The mechanical properties of the fabricated coatings, such as the pendulum hardness, scratch resistance, and impact strength, were studied. The composition of the fabricated coatings was confirmed by attenuated total reflectance infrared spectroscopy measurements. The thermal degradation and indentations were characterized through the use of differential scanning calorimetry and nano-indentation techniques, respectively. The surface morphology of the fabricated coatings was characterized using field-emission scanning electron microscopy. The synergistic effects of the Ag and ZnO nanoparticles on the corrosion resistance of the coatings after different exposure periods in 3.5% NaCl solutions were determined by electrochemical impedance spectroscopy. All the results were consistent with one another and confirmed that the addition of Ag and ZnO nanoparticles improved the mechanical properties of the coatings. This effect also led to a notable increase in the corrosion resistance of the PANI coatings.
Mohammad Asif Alam; Ubair Abdus Samad; El-Sayed M. Sherif; Asiful Seikh; Saeed M. Al-Zahrani; Nabeel H. Alharthi; Manawwar Alam. Synergistic effect of Ag and ZnO nanoparticles on polyaniline incorporated epoxy/2pack coatings for splash zone applications. Journal of Coatings Technology and Research 2019, 16, 835 -845.
AMA StyleMohammad Asif Alam, Ubair Abdus Samad, El-Sayed M. Sherif, Asiful Seikh, Saeed M. Al-Zahrani, Nabeel H. Alharthi, Manawwar Alam. Synergistic effect of Ag and ZnO nanoparticles on polyaniline incorporated epoxy/2pack coatings for splash zone applications. Journal of Coatings Technology and Research. 2019; 16 (3):835-845.
Chicago/Turabian StyleMohammad Asif Alam; Ubair Abdus Samad; El-Sayed M. Sherif; Asiful Seikh; Saeed M. Al-Zahrani; Nabeel H. Alharthi; Manawwar Alam. 2019. "Synergistic effect of Ag and ZnO nanoparticles on polyaniline incorporated epoxy/2pack coatings for splash zone applications." Journal of Coatings Technology and Research 16, no. 3: 835-845.
Ashraf K. Sulieman; Meilana Dharma Putra; Ahmed E. Abasaeed; Mohamed H. Gaily; Saeed M. Al-Zahrani; Mohamed A. Zeinelabdeen. Kinetic modeling of the simultaneous production of ethanol and fructose by Saccharomyces cerevisiae. Electronic Journal of Biotechnology 2018, 34, 1 -8.
AMA StyleAshraf K. Sulieman, Meilana Dharma Putra, Ahmed E. Abasaeed, Mohamed H. Gaily, Saeed M. Al-Zahrani, Mohamed A. Zeinelabdeen. Kinetic modeling of the simultaneous production of ethanol and fructose by Saccharomyces cerevisiae. Electronic Journal of Biotechnology. 2018; 34 ():1-8.
Chicago/Turabian StyleAshraf K. Sulieman; Meilana Dharma Putra; Ahmed E. Abasaeed; Mohamed H. Gaily; Saeed M. Al-Zahrani; Mohamed A. Zeinelabdeen. 2018. "Kinetic modeling of the simultaneous production of ethanol and fructose by Saccharomyces cerevisiae." Electronic Journal of Biotechnology 34, no. : 1-8.
In the present study, high density poly(ethylene) (HDPE)/poly(vinyl alcohol) (PVA) fiber composites were prepared via melt blending technique using a co-rotating twin screw extruder (TSE). The effect of four different PVA fiber concentrations (i.e. 0, 5, 10, 20 wt%) on the melt and crystallization behavior of the HDPE/PVA fiber composites were investigated. The surface morphology of the composites was analyzed by a scanning electron microscopy (SEM). Whereas, the melt and crystallization behavior of the composites were analyzed by a differential scanning calorimetry (DSC). The SEM analysis on the cryo-fractured surface of the HDPE/PVA fiber composites exhibited that the PVA fibers were well blended/distributed in the HDPE matrix. Additionally, the DSC test results showed that the addition of PVA fiber in the HDPE matrix did not significantly change the melting peak temperature (Tm) of the composites. Furthermore, a slight decrease of the crystallization peak temperature (Tc) can be observed when the PVA fiber was incorporated in the HDPE matrix, which indicated a weak nucleation ability of the PVA fibers in the HDPE crystallization process. The same trend was also observed for the crystallinity index (Xc). The crystallinity index of the composites decreased with increasing PVA fiber loadings.
Umi Rofiqah; Achmad Chafidz; Lilis Kistriyani; Mujtahid Kaavessina; Muhammad Rizal; Saeed M. Al Zahrani. Poly(Vinyl Alcohol) Fiber Reinforced High Density Poly(Ethylene) Composites: Melting and Crystallization Behavior. Key Engineering Materials 2018, 773, 100 -105.
AMA StyleUmi Rofiqah, Achmad Chafidz, Lilis Kistriyani, Mujtahid Kaavessina, Muhammad Rizal, Saeed M. Al Zahrani. Poly(Vinyl Alcohol) Fiber Reinforced High Density Poly(Ethylene) Composites: Melting and Crystallization Behavior. Key Engineering Materials. 2018; 773 ():100-105.
Chicago/Turabian StyleUmi Rofiqah; Achmad Chafidz; Lilis Kistriyani; Mujtahid Kaavessina; Muhammad Rizal; Saeed M. Al Zahrani. 2018. "Poly(Vinyl Alcohol) Fiber Reinforced High Density Poly(Ethylene) Composites: Melting and Crystallization Behavior." Key Engineering Materials 773, no. : 100-105.
The trend of using natural fibers as green filler in the fabrication of polymer composites is increasing. One of these natural fibers is date palm fiber (DPF). Date palm fiber is considered as agricultural waste in certain areas, such as Middle East countries. Therefore, the utilization of this fiber in the composites fabrication is an interesting topic of research. In the current study, composites were prepared by melt blending DPF with high density polyethylene (HDPE). Five different DPF loadings were studied (i.e. 0, 5, 10, 20, 30 wt%). The effect of the DPF loadings on the mechanical properties and water absorption behavior of the composites were investigated. The tensile test result showed that tensile strengths of all the composites samples were all higher than the neat HDPE with the maximum improvement was achieved at the DPF loading of 5 wt% (i.e. DFC-5), which was about 19.23 MPa (138% higher than the neat HDPE). Whereas, the flexural test result showed that the flexural strength of the composites slightly increased compared to that of the neat HDPE only until 5 wt% DPF loading (i.e. DFC-5). Afterward, the flexural strength of the DFC-10 was equal to that of the neat HDPE, and decreasing with further increase of DPF loadings. Additionally, the water absorption test result showed that the water absorption rate and uptake of water (at equilibrium) increased with the increase of DPF loading.
Venitalitya Augustia; Achmad Chafidz; Lucky Setyaningsih; Muhammad Rizal; Mujtahid Kaavessina; Saeed M. Al Zahrani. Effect of Date Palm Fiber Loadings on the Mechanical Properties of High Density Polyethylene/Date Palm Fiber Composites. Key Engineering Materials 2018, 773, 94 -99.
AMA StyleVenitalitya Augustia, Achmad Chafidz, Lucky Setyaningsih, Muhammad Rizal, Mujtahid Kaavessina, Saeed M. Al Zahrani. Effect of Date Palm Fiber Loadings on the Mechanical Properties of High Density Polyethylene/Date Palm Fiber Composites. Key Engineering Materials. 2018; 773 ():94-99.
Chicago/Turabian StyleVenitalitya Augustia; Achmad Chafidz; Lucky Setyaningsih; Muhammad Rizal; Mujtahid Kaavessina; Saeed M. Al Zahrani. 2018. "Effect of Date Palm Fiber Loadings on the Mechanical Properties of High Density Polyethylene/Date Palm Fiber Composites." Key Engineering Materials 773, no. : 94-99.
Meilana Dharma Putra; Ashraf K. Sulieman; Ahmed E. Abasaeed; Mohamed H. Gaily; Saeed M. Al-Zahrani; Mohamed A. Zeinelabdeen; Hasan K. Atiyeh. A green process for simultaneous production of fructose and ethanol via selective fermentation. Journal of Cleaner Production 2017, 162, 420 -426.
AMA StyleMeilana Dharma Putra, Ashraf K. Sulieman, Ahmed E. Abasaeed, Mohamed H. Gaily, Saeed M. Al-Zahrani, Mohamed A. Zeinelabdeen, Hasan K. Atiyeh. A green process for simultaneous production of fructose and ethanol via selective fermentation. Journal of Cleaner Production. 2017; 162 ():420-426.
Chicago/Turabian StyleMeilana Dharma Putra; Ashraf K. Sulieman; Ahmed E. Abasaeed; Mohamed H. Gaily; Saeed M. Al-Zahrani; Mohamed A. Zeinelabdeen; Hasan K. Atiyeh. 2017. "A green process for simultaneous production of fructose and ethanol via selective fermentation." Journal of Cleaner Production 162, no. : 420-426.