Rice hulls (RH) and bean hulls (BH) were subjected to prehydrolysis treatments, to define the opt... more Rice hulls (RH) and bean hulls (BH) were subjected to prehydrolysis treatments, to define the optimum conditions for producing a high percentage of hydrolyzed hemicellulose with a small or moderate degradation of the cellulosic portion. The hydrolysis experiments were performed using hydrochloric and sulfuric acids in concentrations ranging from (0.5 to 5)% (w/w) at 120 degrees C for 90 min and 10% consistency. The effects of different temperatures (80 to 120 degrees C) and time (30 to 120 min) on acid hydrolysis of lignocellulosic materials were recorded. It was found that, the optimum condition to hydrolyze the lignocellulosic materials (RH) and (BH) are 2% (w/w) of mineral acid at 120 degrees C for 90 min and 10% consistency. The cellulose crystallinity index in the different types of lignocellulosic materials with and without acid treatment, were increased from 0.32 to 0.46 in case of RH and from 0.43 to 0.61 in case of BH. Due to the lignin depolymerization during the pretreatment process, the relative absorbency of the methoxyl group and the aromatic rings bands were lowered for the pretreated than the untreated lignocellulosic materials. Also, the band at 1730 cm(-1) which is attributed to carbonyl groups of uronic acids was lowered due the hemicellulose hydrolysis.
The combination of cellulosic materials and metal oxide semiconductors can provide composites wit... more The combination of cellulosic materials and metal oxide semiconductors can provide composites with superior functional properties compared to cellulose. By using nanocellulose derived from agricultural waste, we propose a one-pot and environmentally friendly approach to the synthesis of nanocellulose–TiO2 (NC–TiO2) nanocomposites with peculiar photocatalytic activity and antibacterial effects. The as-prepared NC–TiO2 composites were fully characterized by different techniques, such as X-ray diffraction (XRD), μ-Raman, Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and diffuse reflectance spectroscopy (DRS). The results showed that well crystalline anatase TiO2 nanoparticles of about 5–6 nm were obtained. The photocatalytic activity in particular was evaluated by using methyl orange (MO) solution as a target pollutant at different pH values. It was found that all the tested N...
Carbonaceous sorbent from rice-straw that can be used as adsorbents for the purification of water... more Carbonaceous sorbent from rice-straw that can be used as adsorbents for the purification of water were prepared and evaluated. Effects of charring temperature and activation of charring rice straw by acid and alkali on textural and adsorption were investigated. The adsorptive capacities of charring rice straws were measured by Pb ion adsorption. The charring was characterized by electron microscope (SEM) and IR spectrum; roundshaped and porous structures were formed by activation. 2013 Trade Science Inc. INDIA
Heat transfer papers in this work were loaded with a new core-shell pigment based on precipitatin... more Heat transfer papers in this work were loaded with a new core-shell pigment based on precipitating thin shell of titanium dioxide on a core of rice husk silica ash TiO2/RHSA to be applied in dye sublimation printing of textile fabrics. Besides, 0.1%(w/w) cationic polyacrylamide (CPAM) and 1%(w/w) bentonite (Bt) were also added sequentially to improve drainage and filler retention of the paper hand-sheets made from bleached kraft bagasse pulps. The effect of the new core-shell pigment on the mechanical and barrier properties, thermal stability and surface morphology of modified paper sheets were investigated. In addition, the study of transfer printability and ease of dye release from paper to fabric in this heat transfer printing of polyester fabrics using silkscreen printing under different transfer parameters were studied. In addition, fastness measurements including washing, light and perspiration of printing polyester fabric were also estimated.
The current study concerns the valorization of waste rice hulls into value-added materials. To ac... more The current study concerns the valorization of waste rice hulls into value-added materials. To achieve this goal, first, the extraction route of mesoporous silica nanoparticles (SiO2NPs) from rice hulls using citric acid as a carbon template was compared with that prepared by conventional methods of incineration only. Both routes were performed at different temperatures of 600 and 700°C, and the fabricated SiO2NPs were studied by N2 physisorption isotherm, X-ray diffraction (XRD), Fourier transform infrared (FTIR), dynamic light scattering (DLS), and thermogravimetric (TG) analyses. The results show the influence of both routes and temperature on the porous structure, surface area, and charge of as-fabricated SiO2NPs. Furthermore, the physico-chemical features of as-prepared mesoporous SiO2NPs were utilized, in a facile and green way, to prepare silver NPs with high anti-microbial activity. The results were validated by the tools of UV-visible, FTIR, XRD, and XPS spectroscopy. Final...
Microcrystalline cellulose (MCC), as a green material derived from bagasse, was investigated as a... more Microcrystalline cellulose (MCC), as a green material derived from bagasse, was investigated as an additive (0-3 wt%) in the preparation of bagasse paper sheets, in comparison with cationic starch. The effect of MCC addition, in the presence of 15% kaolin or 15% calcium carbonate as paper filler, was also studied. The properties of bagasse paper sheets loaded with MCC or cationic starch, in the presence or absence of 15% kaolin or 15% calcium carbonate as paper filler, were evaluated in terms of breaking length, burst, tear, opacity and filler retention values. Also, SEM and thermal analyses of the paper sheets were performed. It was found that all the properties of the bagasse paper sheets were improved as a result of MCC or cationic starch addition and, in general, the observed improvement increased as the percent of addition increased. Calcium carbonate and cationic starch, in general, gave superior properties, compared to kaolin and MCC, respectively. Overall, MCC could be consi...
Silica was obtained from rice husk (RH) by five different methods. (1) Burning RH as received in ... more Silica was obtained from rice husk (RH) by five different methods. (1) Burning RH as received in muffle at 850 °C for 2 h, (2) RH was firstly burned at 450 °C to reduce its volume. The obtained ash was refluxed with 1N HCl; after washing and drying, ash was burned at 700 °C for 3 h. (3) Un-grinded (or grinded (method 4)) RH was firstly soaked in water, treated with 1N HCl, and burned at 700 °C. (5) To utilize cellulosic fiber, RH was autoclaved with 15% NaOH, and silica was precipitated from the residual liquor. Silica hydrogel was prepared from the obtained ashes by reflux with 2.5 N NaOH followed by neutralization with 1N HCl to form silica gel. The silica gel was filtered, washed, and freeze-dried. XRF analysis confirmed the excellent removal of metal oxide impurities from RHs by acid leaching treatment. Silica precipitated from black liquor shows the most homogeneous particle size. Mesoporous silica with purity over 99% and with a homogeneous particle of average size 41.3–71.3 nm was synthesized using CTAB surfactant as the structure-directing template and RH ash as the silica source.
Microcrystalline cellulose (MCC), as a green material derived from bagasse, was investigated as a... more Microcrystalline cellulose (MCC), as a green material derived from bagasse, was investigated as an additive (0-3 wt%) in the preparation of bagasse paper sheets, in comparison with cationic starch. The effect of MCC addition, in the presence of 15% kaolin or 15% calcium carbonate as paper filler, was also studied. The properties of bagasse paper sheets loaded with MCC or cationic starch, in the presence or absence of 15% kaolin or 15% calcium carbonate as paper filler, were evaluated in terms of breaking length, burst, tear, opacity and filler retention values. Also, SEM and thermal analyses of the paper sheets were performed. It was found that all the properties of the bagasse paper sheets were improved as a result of MCC or cationic starch addition and, in general, the observed improvement increased as the percent of addition increased. Calcium carbonate and cationic starch, in general, gave superior properties, compared to kaolin and MCC, respectively. Overall, MCC could be consi...
Silica was obtained from rice husk (RH) by five different methods. (1) Burning RH as received in ... more Silica was obtained from rice husk (RH) by five different methods. (1) Burning RH as received in muffle at 850 °C for 2 h, (2) RH was firstly burned at 450 °C to reduce its volume. The obtained ash was refluxed with 1N HCl; after washing and drying, ash was burned at 700 °C for 3 h. (3) Un-grinded (or grinded (method 4)) RH was firstly soaked in water, treated with 1N HCl, and burned at 700 °C. (5) To utilize cellulosic fiber, RH was autoclaved with 15% NaOH, and silica was precipitated from the residual liquor. Silica hydrogel was prepared from the obtained ashes by reflux with 2.5 N NaOH followed by neutralization with 1N HCl to form silica gel. The silica gel was filtered, washed, and freeze-dried. XRF analysis confirmed the excellent removal of metal oxide impurities from RHs by acid leaching treatment. Silica precipitated from black liquor shows the most homogeneous particle size. Mesoporous silica with purity over 99% and with a homogeneous particle of average size 41.3–71.3 n...
Materials possessing long-term antibacterial behavior and high cytotoxicity are of extreme intere... more Materials possessing long-term antibacterial behavior and high cytotoxicity are of extreme interest in several applications, from biomedical devices to food packaging. Furthermore, for the safeguard of the human health and the environment, it is also stringent keeping in mind the need to gather good functional performances with the development of ecofriendly materials and processes. In this study, we propose a green fabrication method for the synthesis of silver nanoparticles supported on oxidized nanocellulose (ONCs), acting as both template and reducing agent. The complete structural and morphological characterization shows that well-dispersed and crystalline Ag nanoparticles of about 10–20 nm were obtained in the cellulose matrix. The antibacterial properties of Ag-nanocomposites (Ag–ONCs) were evaluated through specific Agar diffusion tests against E. coli bacteria, and the results clearly demonstrate that Ag–ONCs possess high long-lasting antibacterial behavior, retained up to ...
Rice hulls (RH) and bean hulls (BH) were subjected to prehydrolysis treatments, to define the opt... more Rice hulls (RH) and bean hulls (BH) were subjected to prehydrolysis treatments, to define the optimum conditions for producing a high percentage of hydrolyzed hemicellulose with a small or moderate degradation of the cellulosic portion. The hydrolysis experiments were performed using hydrochloric and sulfuric acids in concentrations ranging from (0.5 to 5)% (w/w) at 120 degrees C for 90 min and 10% consistency. The effects of different temperatures (80 to 120 degrees C) and time (30 to 120 min) on acid hydrolysis of lignocellulosic materials were recorded. It was found that, the optimum condition to hydrolyze the lignocellulosic materials (RH) and (BH) are 2% (w/w) of mineral acid at 120 degrees C for 90 min and 10% consistency. The cellulose crystallinity index in the different types of lignocellulosic materials with and without acid treatment, were increased from 0.32 to 0.46 in case of RH and from 0.43 to 0.61 in case of BH. Due to the lignin depolymerization during the pretreatment process, the relative absorbency of the methoxyl group and the aromatic rings bands were lowered for the pretreated than the untreated lignocellulosic materials. Also, the band at 1730 cm(-1) which is attributed to carbonyl groups of uronic acids was lowered due the hemicellulose hydrolysis.
The combination of cellulosic materials and metal oxide semiconductors can provide composites wit... more The combination of cellulosic materials and metal oxide semiconductors can provide composites with superior functional properties compared to cellulose. By using nanocellulose derived from agricultural waste, we propose a one-pot and environmentally friendly approach to the synthesis of nanocellulose–TiO2 (NC–TiO2) nanocomposites with peculiar photocatalytic activity and antibacterial effects. The as-prepared NC–TiO2 composites were fully characterized by different techniques, such as X-ray diffraction (XRD), μ-Raman, Fourier transform infrared spectroscopy (FTIR), thermogravimetry analysis (TGA), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and diffuse reflectance spectroscopy (DRS). The results showed that well crystalline anatase TiO2 nanoparticles of about 5–6 nm were obtained. The photocatalytic activity in particular was evaluated by using methyl orange (MO) solution as a target pollutant at different pH values. It was found that all the tested N...
Carbonaceous sorbent from rice-straw that can be used as adsorbents for the purification of water... more Carbonaceous sorbent from rice-straw that can be used as adsorbents for the purification of water were prepared and evaluated. Effects of charring temperature and activation of charring rice straw by acid and alkali on textural and adsorption were investigated. The adsorptive capacities of charring rice straws were measured by Pb ion adsorption. The charring was characterized by electron microscope (SEM) and IR spectrum; roundshaped and porous structures were formed by activation. 2013 Trade Science Inc. INDIA
Heat transfer papers in this work were loaded with a new core-shell pigment based on precipitatin... more Heat transfer papers in this work were loaded with a new core-shell pigment based on precipitating thin shell of titanium dioxide on a core of rice husk silica ash TiO2/RHSA to be applied in dye sublimation printing of textile fabrics. Besides, 0.1%(w/w) cationic polyacrylamide (CPAM) and 1%(w/w) bentonite (Bt) were also added sequentially to improve drainage and filler retention of the paper hand-sheets made from bleached kraft bagasse pulps. The effect of the new core-shell pigment on the mechanical and barrier properties, thermal stability and surface morphology of modified paper sheets were investigated. In addition, the study of transfer printability and ease of dye release from paper to fabric in this heat transfer printing of polyester fabrics using silkscreen printing under different transfer parameters were studied. In addition, fastness measurements including washing, light and perspiration of printing polyester fabric were also estimated.
The current study concerns the valorization of waste rice hulls into value-added materials. To ac... more The current study concerns the valorization of waste rice hulls into value-added materials. To achieve this goal, first, the extraction route of mesoporous silica nanoparticles (SiO2NPs) from rice hulls using citric acid as a carbon template was compared with that prepared by conventional methods of incineration only. Both routes were performed at different temperatures of 600 and 700°C, and the fabricated SiO2NPs were studied by N2 physisorption isotherm, X-ray diffraction (XRD), Fourier transform infrared (FTIR), dynamic light scattering (DLS), and thermogravimetric (TG) analyses. The results show the influence of both routes and temperature on the porous structure, surface area, and charge of as-fabricated SiO2NPs. Furthermore, the physico-chemical features of as-prepared mesoporous SiO2NPs were utilized, in a facile and green way, to prepare silver NPs with high anti-microbial activity. The results were validated by the tools of UV-visible, FTIR, XRD, and XPS spectroscopy. Final...
Microcrystalline cellulose (MCC), as a green material derived from bagasse, was investigated as a... more Microcrystalline cellulose (MCC), as a green material derived from bagasse, was investigated as an additive (0-3 wt%) in the preparation of bagasse paper sheets, in comparison with cationic starch. The effect of MCC addition, in the presence of 15% kaolin or 15% calcium carbonate as paper filler, was also studied. The properties of bagasse paper sheets loaded with MCC or cationic starch, in the presence or absence of 15% kaolin or 15% calcium carbonate as paper filler, were evaluated in terms of breaking length, burst, tear, opacity and filler retention values. Also, SEM and thermal analyses of the paper sheets were performed. It was found that all the properties of the bagasse paper sheets were improved as a result of MCC or cationic starch addition and, in general, the observed improvement increased as the percent of addition increased. Calcium carbonate and cationic starch, in general, gave superior properties, compared to kaolin and MCC, respectively. Overall, MCC could be consi...
Silica was obtained from rice husk (RH) by five different methods. (1) Burning RH as received in ... more Silica was obtained from rice husk (RH) by five different methods. (1) Burning RH as received in muffle at 850 °C for 2 h, (2) RH was firstly burned at 450 °C to reduce its volume. The obtained ash was refluxed with 1N HCl; after washing and drying, ash was burned at 700 °C for 3 h. (3) Un-grinded (or grinded (method 4)) RH was firstly soaked in water, treated with 1N HCl, and burned at 700 °C. (5) To utilize cellulosic fiber, RH was autoclaved with 15% NaOH, and silica was precipitated from the residual liquor. Silica hydrogel was prepared from the obtained ashes by reflux with 2.5 N NaOH followed by neutralization with 1N HCl to form silica gel. The silica gel was filtered, washed, and freeze-dried. XRF analysis confirmed the excellent removal of metal oxide impurities from RHs by acid leaching treatment. Silica precipitated from black liquor shows the most homogeneous particle size. Mesoporous silica with purity over 99% and with a homogeneous particle of average size 41.3–71.3 nm was synthesized using CTAB surfactant as the structure-directing template and RH ash as the silica source.
Microcrystalline cellulose (MCC), as a green material derived from bagasse, was investigated as a... more Microcrystalline cellulose (MCC), as a green material derived from bagasse, was investigated as an additive (0-3 wt%) in the preparation of bagasse paper sheets, in comparison with cationic starch. The effect of MCC addition, in the presence of 15% kaolin or 15% calcium carbonate as paper filler, was also studied. The properties of bagasse paper sheets loaded with MCC or cationic starch, in the presence or absence of 15% kaolin or 15% calcium carbonate as paper filler, were evaluated in terms of breaking length, burst, tear, opacity and filler retention values. Also, SEM and thermal analyses of the paper sheets were performed. It was found that all the properties of the bagasse paper sheets were improved as a result of MCC or cationic starch addition and, in general, the observed improvement increased as the percent of addition increased. Calcium carbonate and cationic starch, in general, gave superior properties, compared to kaolin and MCC, respectively. Overall, MCC could be consi...
Silica was obtained from rice husk (RH) by five different methods. (1) Burning RH as received in ... more Silica was obtained from rice husk (RH) by five different methods. (1) Burning RH as received in muffle at 850 °C for 2 h, (2) RH was firstly burned at 450 °C to reduce its volume. The obtained ash was refluxed with 1N HCl; after washing and drying, ash was burned at 700 °C for 3 h. (3) Un-grinded (or grinded (method 4)) RH was firstly soaked in water, treated with 1N HCl, and burned at 700 °C. (5) To utilize cellulosic fiber, RH was autoclaved with 15% NaOH, and silica was precipitated from the residual liquor. Silica hydrogel was prepared from the obtained ashes by reflux with 2.5 N NaOH followed by neutralization with 1N HCl to form silica gel. The silica gel was filtered, washed, and freeze-dried. XRF analysis confirmed the excellent removal of metal oxide impurities from RHs by acid leaching treatment. Silica precipitated from black liquor shows the most homogeneous particle size. Mesoporous silica with purity over 99% and with a homogeneous particle of average size 41.3–71.3 n...
Materials possessing long-term antibacterial behavior and high cytotoxicity are of extreme intere... more Materials possessing long-term antibacterial behavior and high cytotoxicity are of extreme interest in several applications, from biomedical devices to food packaging. Furthermore, for the safeguard of the human health and the environment, it is also stringent keeping in mind the need to gather good functional performances with the development of ecofriendly materials and processes. In this study, we propose a green fabrication method for the synthesis of silver nanoparticles supported on oxidized nanocellulose (ONCs), acting as both template and reducing agent. The complete structural and morphological characterization shows that well-dispersed and crystalline Ag nanoparticles of about 10–20 nm were obtained in the cellulose matrix. The antibacterial properties of Ag-nanocomposites (Ag–ONCs) were evaluated through specific Agar diffusion tests against E. coli bacteria, and the results clearly demonstrate that Ag–ONCs possess high long-lasting antibacterial behavior, retained up to ...
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