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In this work heat transfer papers 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 silk-screen printing under different transfer parameters were studied. Also, fastness measurements including washing, light and perspiration of printing polyester fabric were also estimated. [ABSTRACT FROM AUTHOR]

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 NC–TiO2 nanocomposites showed stable photocatalytic activity, even after consecutive photocatalytic runs. In addition, NCT nanocomposites with higher TiO2 content showed degradation efficiency of almost 99% towards MO after 180 min of UV illumination. Finally, NC–TiO2 nanocomposites also showed intriguing antimicrobial properties, demonstrating to be effective against Gram-positive (Staphylococcus aureus, Bacillus subtilis) with 20–25 mm of inhibition zone and Gram-negative bacteria (Escherichia coli, Pseudomonas aeuroginosa) with 21–24 mm of inhibition zone, and fungi (Candida albicans) with 9–10 mm of inhibition zone. [ABSTRACT FROM AUTHOR]

Packaging is as important as the product itself because it is a crucial marketing and communication tool for business. Oxidized nanocellulose (ONC), extracted from agriculture residues of bagasse raw material using ecofriendly ammonium persulfate hydrolysis method, is used as support/reducing agent for the generation of silver nanoparticles (AgNPs) via photochemical procedure and reinforcing element in paper functionalization. The natural polymer, sodium alginate (SA) is exploited to enhance the binding of the ONC-AgNPs over cellulose fibers. The SA/ONC-AgNPs bio-nanocomposite is incorporated on paper matrix, which represents a more suitable choice respect to other substrates for its renewable, biocompatible, biodegradable, and cost-effective properties. Structural and antimicrobial evaluations show that the papers embedded with the SA/ONC-AgNPs possess good mechanical, thermal, barrier and antibacterial properties. [ABSTRACT FROM AUTHOR]

In the current work, we present a renewable alternative coating formulation made of durable titania nanoparticles and oxidized nanocellulose (TiO 2 NPs@OCNs) nanocomposites and sodium alginate (SA), to create an environmentally friendly and secure food packaging paper. OCNs sugarcane fibers are firstly hydrolyzed using ammonium persulphate (APS). Then, TiO 2 NPs@OCNs nanocomposites are made in situ with OCNs using a green water-based sol-gel synthesis. Gram (+) microorganisms as well as Gram (−) bacteria are used to test the antibacterial properties of the TiO 2 NPs@OCN dispersions. The results show that the TiO 2 NP@OCNs significantly decreases the growth for all bacterial species. The TiO 2 NP@OCNs nanocomposites are mixed with SA, and the resulting formulations are used to coat paper sheets. The corresponding physicochemical properties are evaluated using FTIR, TGA, AFM, SEM, and EDX. Furthermore, the mechanical strength, air permeability, and water vapor characteristics of the paper sheets treated with SA/TiO 2 NPs@OCN are carried out, resulting in a great improvement of these properties. Finally, the SA/TiO 2 NPs@OCNs coated papers have been used as packaging for strawberries. The findings demonstrate that coated papers could preserve strawberry quality better than unpacked fruit and extend strawberry shelf life from 6 to 18 days. [ABSTRACT FROM AUTHOR]

With the uprising global challenges in power resources, scarcity of raw material and environmental hazards; agricultural wastes can be a corner stone in facing these challenges. Agricultural residues are used in different applications e.g. biomass energy, fertilizers, livestock feeding, furniture, pulp and paper industry and others. Rice straw, bagasse and cotton stalks residues are produced in Egypt annually in mass amounts. The annual production of agriculture wastes in Egypt is approximately 30–35 million tons. These huge amounts of residues have the potential to be an economic opportunity for the already troubled Egyptian economy. Microfibrillated cellulose Egypt 30 (MFCE30) is an agricultural residue, which is chemically and mechanically treated. MFCE30 has been produced and examined as a substitute for the imported wood pulp to be used as an additive in the Egyptian pulp and paper industry. The present study discusses the effectiveness, strategic evaluation and market analysis of MFCE30 in Egypt. [ABSTRACT FROM AUTHOR]

Due to their abundance, nano-scalecellulose fiber materials such as microfibrillated cellulose, serve as promising candidates for nanocomposite production. Such new high-value materials are the subject of continuing research of new products from the pulp and paper industry sector. Microfibrillated cellulose (MFC) is generally considered to be composed of fibrils with diameter in the range of 10–100 nm liberated from larger plant based cellulose fibers and have a broad range of potential applications. In this work, we evaluated the preparation of MFC from biomass wastes using a new chemical pretreatment method before applying the traditional mechanical method. Rice straw, bagasse and cotton stalk biomass wastes used in this study were chemically treated with sodium hydroxide-sodium sulphite in order to remove lignin, hemicelluloses and to isolate cellulose, which was our starting material for the preparation of MFC. MFC was isolated from the bleached materials by mechanical treatment and the resulting materials were named MFCE30. The resulting MFCE30 were characterized by optical and scanning electron microscopies (SEM), Fourier Transform infrared spectroscopy (FTIR) and X-Ray diffraction. Composite paper sheet samples were prepared from bleached rice straw and bagasse pulps by adding different percentages of MFCE30 and both mechanical and optical properties of the resulting papers were studied. These properties were compared with those of paper sheets conventionally prepared in the pulp and paper Egyptian industry by adding 20% wood pulp as additive. [ABSTRACT FROM AUTHOR]

In this work, new core-shell pigment based on precipitating a small amount of titanium dioxide on precipitated calcium carbonate (CC) were applied once as filler in paper sheet making and another time was mixed with chitosan as a coat on the papers. The prepared pigments were characterized to confirm their preparation. The mechanical and optical properties of both filled and coated paper sheets and their individual components (TiO 2 and CC) were performed to compare their effect on the paper sheets using SEM, TGA and UV aging. [ABSTRACT FROM AUTHOR]

Abstract: Microcrystalline cellulose was prepared from bean hull, rice straw and rice hull. The use of rice hull and rice straw pulp in different proportions as a source of silica to prepare silicified microcrystalline cellulose was investigated. Preparations of microcrystalline cellulose–potato starch composites with different potato starch concentrations were performed. All samples were characterized through various techniques. Physical and mechanical properties of the prepared tablets were tested. The biological activities of one composite was tested in a hyperlipidemic rat model and compared to orlistat to assess its antilipidemic potential. This composite exhibited remarkable antilipidemic effect with decreased insulin sensitivity. [Copyright &y& Elsevier]

In this study, a simple method based on non-ionic surfactant polysorbates-80 was used to create mesoporous γ-Al2O3NPs. The properties of the prepared mesoporous alumina nanoparticles (Al2O3NPs) were verified using ATR-FTIR, XRD, SEM, TEM, DLS, and BET surface area analysis. Then, thin-film nanocomposite (TFN) nanofiltration membranes were fabricated by interfacial polymerization of embedded polyamide layers with varied contents (0.01 to 0.15 wt.%) of mesoporous γ-Al2O3NPs. The surface roughness, porosity, pore size, and contact angle parameters of all the prepared membranes were also determined. The performance of the fabricated membranes was investigated under various mesoporous γ-Al2O3NPs loads, time, and pressure conditions. Mesoporous γ-Al2O3NPs revealed an important role in raising both the membrane hydrophilicity and the surface negativity. The addition of 0.03 wt.% mesoporous γ-Al2O3NPs to the TFN membrane increased water flux threefold compared to the TF control (TFC) membrane, with maximum water flux reaching 96.5, 98, 60, and 52 L/(m2.h) for MgSO4, MgCl2, Na2SO4, and NaCl influent solutions, respectively, with the highest salt rejection of 96.5%, 92.2%, 98.4%. The TFN-Al2O3 membrane was also able to soften water and remove polyvalent cations such as Mg2+ with a highly permeable flux. The TFN-Al2O3 membrane successfully removed the hardness of the applied water samples below the WHO limit compared to using merely the TFC membrane. Furthermore, the TFN-Al2O3 nanofiltration membrane unit proved to be a promising candidate for the desalination of real brine like that collected from the Safaga area, Egypt. [ABSTRACT FROM AUTHOR]

Abstract: Microcrystalline cellulose (MCC) is a very important product in pharmaceutics, foods, cosmetics and other industries. In this work, MCC was prepared from rice and bean hulls (RH and BH). Hydrolysis of bleached pulps was carried out using hydrochloric or sulfuric acid to study the effect of the acid used on the properties of the produced MCC. MCC samples prepared from RH and BH were characterized through various techniques, scanning electron microscopy (SEM), infrared spectroscopy (FTIR), thermogravimetry analysis (TGA) and X-ray diffraction and compared with commercial MCC. The mechanical properties of tablets made from MCC of different lignocellulosic materials were tested and compared to a commercial MCC. [ABSTRACT FROM AUTHOR]

Abstract: Binary and ternary complexes of Ni2+, Cu2+, Ag+ and UO2 2+ with the prepared carboxymethyl cellulose in its sodium salt (P-NaCMC) and pyridine (py) as secondary ligand have been prepared. Probable structures of the binary and ternary complexes were inferred via elemental analysis, spectral data (IR, mass and solid reflectance) as well as magnetic susceptibility measurements, thermal and XRPD analysis. The change in the selected vibrational absorption bands in IR spectrum of P-NaCMC upon coordination with metal ions investigates the coordination mode of P-NaCMC to be the two vicinal uncarboxylated diol groups (2- and 3-hydroxyl groups) of the glucopyranose rings in addition to the carbonyl oxygen atom of the carboxylate group while the coordination mode of pyridine ligand is the ring nitrogen. The mass spectra confirmed the proposed structure of the synthesized compounds. The solid reflectance spectral data and magnetic moment measurements suggest the geometrical structures for the metal complexes. Thermal studies suggest a mechanism for degradation of P-NaCMC and its metal complexes as function of temperature supporting the chelation modes. Also, the activation thermodynamic parameters, such as, ΔE *, ΔH *, ΔS * and ΔG * for the different thermal decomposition steps of P-NaCMC and its metal complexes were calculated. Antimicrobial activities of P-NaCMC and its binary and ternary complexes were studied against S. aureus and S. pyogenes (Gram-positive bacteria), P. phaseolicola and P. fluorescens (Gram-negative bacteria) and the fungi; F. oxysporum and A. fumigates using agar disc diffusion method. The results showed that all the metal complexes, especially Cu2+ ternary complex have higher antibacterial and antifungal activities than P-NaCMC. [ABSTRACT FROM AUTHOR]

Abstract: 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°C for 90min and 10% consistency. The effects of different temperatures (80 to 120°C) and time (30 to 120min) 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°C for 90min 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 1730cm−1 which is attributed to carbonyl groups of uronic acids was lowered due the hemicellulose hydrolysis. [Copyright &y& Elsevier]

A practical fluorescent test dipstick for an efficient recognition of ammonia and amines vapors was developed. The prepared testing strip was based on a composite of molecularly imprinted chitosan nanoparticles, supported on cellulose paper assay, with artificial fluorescent receptor sites for ammonia/amines recognition in aqueous and gaseous phases. A modified chitosan nanoparticles containing fluorescein molecules, were successfully prepared and employed on cellulose paper strip creating fluorescent cellulose (FL-Cell) to act as "turn-on" fluorescent sensor for sensing and determining ammonia and organic amine vapor. We employed chitosan nanoparticles that had fluorescein incorporated as the fluorescent probe molecule, with a readout limit achieved for aqueous ammonia as low as 280 ppm at room temperature and atmospheric pressure. The sensor responded linearly relying on the aqueous ammonia concentration in the range of 0.13–280 ppm. The chromogenic fluorescent cellulose platform response depended on the acid-base characteristic effects of the fluorescein probe. The protonated form of fluorescein molecules immobilized within the chitosan nanoparticles were in a nanoenvironment demonstrating only weak fluorescence. When binding to ammonia/amine vapor, the fluorescein active sites were deprotonated and exhibited higher "turned-on" fluorescence as a result of exposure to those alkaline species. The simple fabrication and abovementioned characteristics of such fluorescent chitosan nanoparticles are such that they should be applicable for monitoring of ammonia/amines in either aqueous or vapor states. We studied the distribution of the fluorescent chitosan onto paper sheets fabricated from bleached bagasse pulp and coated with two different thicknesses of a fluorescent nanochitosan and blank nanochitosan solutions. A thin fluorescent nanochitosan layer was created on the surface of cellulose strips using an applicator. Its distribution was assessed by scanning electron microscopic (SEM) and transmission electron microscopic (TEM) analysis as well as Fourier-transform infrared spectroscopic (FT-IR) measurements. The mechanical properties were also tested. The exploitation of this "turn-on" fluorescence sensor invented platform should be amenable to different situations where determination of ammonia/amine vapor or aqueous solution is required. [ABSTRACT FROM AUTHOR]

Newly and highly silicified oxidized cellulose nanocrystals (SOCNs) from rice straw were prepared using a very fast and eco-friendly method. SOCN whiskers were prepared in a microwave reactor using ammonium persulfate. The reaction occurred in one step under the optimal conditions (concentration, liquor ratio, temperature, and time), saving time and energy. The isolated SOCN whiskers were used in a novel alternative dyeing technique to color wool fabric that further helps reduce the pollution caused by the textile coloration process (i.e., reducing the percentage of water consumed in the coloration process of wool fabric and wastewater effluent). The SOCNs and dyed wool fabric were fabricated using a range of techniques. Up to 60% less water was used in the coloring process than is necessary for conventional methods. The wool fabric dyed with SOCN whiskers has better color strength and fastness properties than conventional dyeing, as well as improved thermal stability and ultraviolet rays blocking activity without additional processing. [Display omitted] • Novel SOCNs with high content of silica (32.30 %) were extracted from rice straw pulp. • The extraction was done in an eco-friendly, short time and energy-saving manner using APS hydrolysis under MW irradiations. • The isolated SOCN-MW whiskers were utilized in a novel alternative dyeing technique for the coloration of wool fabric. • The new proposed dyeing approach helps in the reduction of pollution caused by conventional textile coloration process. • SOCN-MW dyed wool gained extra properties (e.g. improved thermal stability & UPF) without undergoing additional treatments. [ABSTRACT FROM AUTHOR]

Abstract: This work focused on studying the dependence of paper sheet strength properties on the composition of additives, namely chitosan, cyanoethyl and carboxymethyl chitosan. Chitosan and its derivatives enhanced the strength properties of unagged and aged paper sheets. Also, cyanoethyl chitosan improved the dielectric properties of the treated paper sheets. The dielectric study was carried out over a frequency range from 100Hz to 100kHz at temperature range from 20 to 140°C. The variations of permittivity ε′ versus the cyanoethyl chitosan content at three different temperatures show the highest dielectric properties at cyanoethyl chitosan of 0.3%. The variation of ε″ versus the applied frequency was fitted by a superposition of Fröhlich and Havriliak–Negami functions in addition to the conductivity term. These functions could be ascribed by the Maxwell–Wagner effect and the orientation of the large aggregates formed by the addition of chitosan to the paper sheet. [Copyright &y& Elsevier]