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Protein delivery journey through gastrointestinal (GI) tract faces many challenges due to its physicochemical instabilities, fugitive half-life, and less absorption efficiency. Herein, the aim is the study of both the encapsulation and in-vitro-release of the bovine serum albumin (BSA) through pHs of GI tract within the green synthesized interpolyelectrolyte complex, which was prepared from biodegradable polymers as XG and TMC-based highly an efficient pH-sensitive protein carrier to solve the drawbacks of the protein delivery through GI tract. The structures of XG/TMC PEC and BSA-loaded PEC were elucidated using different analysis tools like FTIR, FE-SEM, EDX, and XRD techniques. The BSA-loaded and released profiles were determined in pH 1.2 (gastric simulated pH) and pH 7.4 (intestine simulated pH) media. Best BSA-loaded results were obtained with the increase in XG concentration, BSA-loaded concentration, and encapsulation time. Moreover, in vitro BSA release results showed that the amount of BSA released in pH 7.4 was higher than that in pH 1.2 and also went up with the rise within the amount from 12 to 120 h to be 97.9% in pH 7.4 and 29.7% in pH 1.2 at 120 h. Moreover, according to SDS-PAGE technique, the BSA was released in intact form out of the PECs; thus, the encapsulation and released conditions did not affect the structural integrity of BSA structure. Finally, the cytotoxicity study of the prepared PEC showed safe and good biocompatibility properties against the traditional human melanocyte cell line.

Spherical polyacrylamide nanoparticles (PAM-NPs) were prepared by inverse emulsion polymerization technique. Polyacrylamide/functionalized-multiwalled carbon nanotubes (PAM/f-MWCNTs) and polyacrylamide/TiO2 (PAM/TiO2) nanocomposites were successfully prepared by in situ emulsion polymerization and solution mixing methods to investigate their efficiencies in removal of organic dyes. The super-hydrogel behavior of the prepared nanocomposites proved water absorbance of 3664% and 2996% for PAM/1% f-MWCNT and PAM/10% TiO2 nanocomposites; respectively. A maximum photodegradation efficiency of 35% was achieved upon using PAM/10% TiO2 nanocomposite for CR dye removal, while in case of MG dye it reached 76% after 240 min irradiation time. Dye removal efficiency increased as f-MWCNT loading increased and reached maximum values of 49% and 80% for CR and MG dyes, respectively, using PAM/1% f-MWCNT nanocomposite after 240 min irradiation time. Pseudo-second-order kinetic model best fitted the adsorption kinetics behavior which reached maximum rates of 0.0615 and 0.463 for CR and MG dyes, respectively, using PAM/1% f-MWCNT nanocomposite. However, in the case of PAM/10% TiO2 nanocomposite it was found that adsorption reached maximum rates of 0.552 and 0.571 for CR and MG dyes, respectively. On the other hand, pseudo-first-order kinetic model best described the photodegradation behavior of the prepared nanocomposites with higher degradation rate of 0.0018 and 0.0075 for CR and MG dyes, respectively, using PAM/10% TiO2 nanocomposite. In this work, the combination of PAM-NPs, prepared by inverse emulsion polymerization, TiO2 NPs with photocatalytic activity and CNTs with high adsorption activity combined the photocatalytic and absorption activities of these nanoparticles in conjunction with reducing their amounts and diminishing the risk of fine catalyst dispersion in the treated water.

Hydrogels could be employed in agriculture for efficient management of water and controlled-release urea (CRU). This study aimed to synthesize a superabsorbent hydrogel for CRU by cross-linking sodium alginate (Alg) and N-(2-hydroxy-3-trimethyl ammonium) propyl chitosan chloride (HTACC). The hydrogel structure was characterized by various techniques, and the urea loading and releasing behaviors of the synthetic hydrogels were investigated. The results revealed that the maximum urea loading ranged between 107 and 200%, and that the urea loading kinetics fitted with Langmuir model followed by the Freundlich model. The urea release behavior reached equilibrium after 30 days and urea releasing kinetics fitted with the zero-order and Higuchi models. The synthesized hydrogels exerted significant antimicrobial activities and molecular docking showed their binding affinity toward glucosamine-6-phosphate synthase, β-lactamase II, TraR binding site and nucleoside diphosphate kinase. In conclusion, these Alg/HTACC hydrogels showed swelling, urea release, and antimicrobial properties suitable to meet the plant requirements and produce economic and environmental benefits.

Food contamination by foodborne pathogens is considered a serious problem worldwide. This study aimed to show the efficacy of the one-pot green biosynthesis of nanocomposites as effective antimicrobial agents based on a water-soluble biodegradable polysaccharide and silver nitrate (AgNO3). Silver (Ag) nanoparticles were synthesized using different concentrations of AgNO3 solution (1, 2, and 3 mM) in the presence of N-quaternized chitosan and N,N,N-trimethyl chitosan chloride (TMC) as both a reducing and stabilizing agent. In addition, the structure of TMC/Ag nanocomposites was confirmed using different analytical tools including FTIR, UV-Vis, XRD, HR-TEM, FE-SEM, and EDX techniques. The FTIR spectra and UV-Vis spectra showed the main characteristic absorption peaks of Ag nanoparticles. In addition, FE-SEM images showed the formation of spherical bead-like particles on the surface of TMC. Correspondingly, the EDX spectrum showed a peak for silver, indicating the successful synthesis of Ag nanoparticles inside the TMC chains. Moreover, HR-TEM images exhibited the good distribution of Ag nanoparticles, which appeared as nano-spherical shapes. The antimicrobial activity of TMC/Ag nanocomposites was examined against three foodborne pathogens, including Salmonella Typhimurium as a Gram-negative bacterium, Bacillus subtilis as a Gram-positive bacterium and Aspergillus fumigatus as a fungus. The results showed that TMC/Ag nanocomposites had better antimicrobial activity compared with TMC alone and their antimicrobial activity increased with an increase in the concentration of Ag. The results confirmed that the TMC/Ag nanocomposites can be potentially used as an effective antimicrobial agent in food preservation. This work was supported by Cairo University-Faculty of Science fund 2020. Furthermore, AES thanks the National Research grants from MINECO, Spain, "Juan de la Cierva" [FJCI-2018-037717] and he is currently on leave from CMRDI.

Scale deposition is considered as one of the most critical problems leading to permeate flux decline and deterioration of membrane surface in reverse osmosis (RO) desalination plants. This study aims to preparation of novel high effective scale inhibitor, chitosan biguanidine hydrochloride (CG), to inhibit the precipitation of calcium sulfate and carbonate onto the membrane surface. The modification of Chitosan by the guanidine group was to enhance its solubility in water, because chitosan as it is dissolves only in moderately acidic solutions. CG was synthesized and characterized by FTIR, 13C NMR and 1H NMR. The inhibition efficiency of our antiscalant was evaluated against CaSO4 and CaCO3 solutions at both static (induction time) and real application tests (cross-flow unit for 6 h). CG showed a good performance as scale inhibitor for CaSO4 and CaCO3 at about 10 and 15 mg·L−1 with flux decline of 2.6 and 5% in feed water, respectively. In addition, the induction time of precipitation of CaSO4 increased from 3 to 15 min with the addition of CG. SEM analysis at different magnifications for Cs and CG proved that CG strongly affects the morphology of the precipitated calcium sulfate and calcium carbonate leading to distortion of crystals. Keywords: Reverse osmosis, Antiscalant, Calcium sulfate scale, Calcium carbonate scale, Chitosan biguanidine hydrochloride

This study aims to prepare binary edible films made from carboxymethyl cellulose (CMC) and chitosan biguanidine hydrochloride (CBg) activated with frankincense oil (FO). The interactions between CMC, CBg and FO were confirmed by FTIR. XRD showed that the addition of FO led to decreasing the crystallinity of CMC/CBg films. The water vapour permeability was reduced upon increasing the FO content. The presence of FO made the films brighter and didn't change their transparency as detected from the color measurements. The films exhibited better mechanical properties in the presence of FO as detected from the improved values of both tensile strength and elongation at break. The prepared films exhibited excellent antibacterial activity especially at high content of FO (5%). CMC/CBg/FO films might be used potentially in the production of edible films due to their excellent physical and antibacterial properties.

Conducting polymers have great attention due to their electrical activity in π-electrons conjugation over backbone of the polymeric chain. These properties make them attractive for enormous applications. On that account, we prepared polyanisidines (PAs) derivatives ( ortho, meta, and para) by chemical oxidation process using ammonium peroxydisulfate as an initiator. The prepared PAs were characterized using various techniques. Moreover, conductivity measurements of PA derivatives showed that the ortho-derivative gave the highest value. The prepared PAs were investigated as photostabilizers for poly(vinyl chloride) (PVC) films. Different PVC films were prepared in the absence and the presence of PA derivatives and they were exposed to ultraviolet (UV) irradiation for 30 days. The gel weight % for irradiated PVC films was followed as a function of irradiation time. The results revealed that the blank PVC film (free PA derivatives) was completely degraded reaching 100% gel content. PVC films contain PA derivatives showed higher photostability than PVC blank film. A comparison between the investigated PA derivatives as UV stabilizers and Chimassorb commercial UV absorber was also investigated. PA derivatives showed better efficiency as UV stabilizers than the commercial one till 288 h of UV irradiation.

As water is the most important source for survival for all individuals around the world, water pollution via synthetic toxic dyes and microorganisms is considered as a serious worldwide environmental problem. The present work aimed to synthesize crosslinked grafted xanthan gum (XG) films with poly ( N -vinyl imidazole), PVI, for both removing crystal violet (CV) dye and inhibiting Escherichia coli ( E. coli ) growth. XG- grafted -PVI was prepared using potassium persulfate as an initiator to give different percentage of graft yield and using N , N ′-methylene bisacrylamide (MBA) as a crosslinking agent. The structure of grafted XG films was elucidated via various analysis tools including FTIR, XRD, FE-SEM and EDX. Results of CV adsorption studies showed that maximum CV removal was 99.7% (625 mgg −1 ) which was achieved at: 95% GY, 2.5% MBA, 40 mg of adsorbent into 50 mL of 500 mgL −1 CV dye solution, pH 7, temperature (30 °C) and adsorption time (7 h). Also, results fitted well with Langmuir isotherm model. Moreover, pseudo-first order and intraparticle diffusion model participated in the mechanism of CV adsorption on grafted XG surface, in addition to its efficient recycling ability. Furthermore, antibacterial activities results of crosslinked grafted XG revealed their high inhibiting effect for E. coli growth.

the aim of this study was to assess the effect of silanized silicon dioxide and titanium dioxide nanoparticles loading on the compressive strength of experimentally prepared resin composite core material. Materials andMethods: Resin matrix was prepared by adding 70 wt% Bis-GMA,30 wt% TEGDMA, 0.5 wt% CQ and 0.5 wt% EDAB. Sintering of the silica nanoparticles was performed and then the silanized sintered silica fillers together with titanium dioxide nanoparticles and silica nanoparticles were mixed with the prepared resin matrix. Specimens of the experimental and control resin composite were prepared in split Teflon moulds (4x6mm) for compressive strength testing using universal testing machine. Results: There was no statistically significant difference between results of the experimental and control resin composites. Conclusion: Addition of up to 85 wt% of nanofillers into traditional resin matrix produced a resin composite with comparable compressive strength to that of the commercial composite products commonly used as core material

N-vinyl imidazole (NVI) was grafted onto gelatin using potassium persulphate (KPS) as thermal initiator in aqueous medium. The effects of various parameters such as different KPS and NVI concentrations, the time and reaction temperature on the grafting process have been investigated. The optimum conditions were found to get the highest grafting efficiency as follow [KPS] = 6 × 10−3 mol L−1, [NVI] = 1.5 mol L−1 at reaction temperature 60 °C for 90 min. The grafted gelatin copolymers were characterized using different techniques namely Fourier transform infrared (FTIR) and 1H NMR spectroscopy, scanning electron microscope, X-ray diffraction (XRD) and thermal analysis. The antibacterial activity of gelatin and its grafted copolymers was evaluated. The highest percent of grafting (G% = 215%) showed strong improvement in activity of gelatin against gram-negative bacteria used Escherichia coli and Klebsiella pneumonia. In case of Klebsiella pneumonia, grafted gelatin copolymer showed the same inhibition zone of gentamicin (standard antibiotic).

To improve the Vicat Softening Point of PVC compounds, blending technique was used to blend PVC with other polymers such as Acrylonitrile butadiene styrene (ABS), Acrylonitrile styrene acrylate (ASA) and Poly (methyl methacrylate) (PMMA) at different ratios (5, 10 and 20 %), then comparing the mechanical and thermal properties obtained with commercial heat modifier polymer Alpha Methyl Styrene-Acrylonitrile copolymer (AMSAN) The blended PVC mixtures were studied to find that, the best polymer that can be used to improve the Vicat Softening point. It was the blend of PVC with PMMA. Also, the effect of adding inorganic fillers to PVC mixtures such as Calcium Carbonate and Talc with different particles size at different amounts (5, 10 and 20 phr) were mechanically and thermally studied to find that, the suitable type of filler which can be used in enhancing the Vicat softening point, where it was Talc with particles size 0.7 Micron. By preparing the two best results achieved with PVC mixture which include PMMA and 0.7 Micron Talc it was obtained the highest Vicat softening point (VSP). It reached to 80.6 oC where it was 70.5 oC for the PVC without VSP improver and reached to 77.1 oC using commercial VSP improver.

Epoxy/nanoclay composites based on diglycidyl ether of bisphenol-A was cured by isophoronediamine and different weight percents of organically modified montmorillonite (O-MMT) clay (3, 5 and 7 wt%). Epoxy/nanoclay composites were characterized by different techniques such as Fourier transform infrared spectroscopy, scanning electron microscopy and X-ray diffraction. The compressive strength of the epoxy/nanoclay composite with a 3 wt% of O-MMT was higher than that of pure epoxy and other composites. Thermogravimetric analysis showed no change in the thermal behaviour of the cured epoxy after incorporation of O-MMT.

Enhancement of the physicomechanical properties of rubber can be achieved by the incorporation of reinforcing fillers, such as clay. Cation-exchanged zeolites (CEZes) were prepared by exchanging the native Na+ ions with single inorganic cations (magnesium (Mg), zinc (Zn), or strontium) and/or double cations (Zn-Mg), then they were processed as reinforcing fillers in the two type of synthetic rubber, acrylonitrile-butadiene rubber (NBR) and styrene-butadiene rubber (SBR). Characterization of modified zeolite (Ze) was implemented using infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The aim of this article is to study the influence of Ze and CEZe loadings on the rheometrical and physicomechanical properties of both NBR and SBR composites, also the thermogravimetric analysis was examined and the results were discussed. The results showed that the composites exhibited remarkable improvements in tensile strength, elongation at break, and hardness in the presence of CEZe and also an increase in thermal stability was reported.

In this study, we aim to prepare novel bioactive edible films based on sodium alginate and castor oil (CO). The chemical structures and crystallinity were investigated using FTIR and XRD, respectively. Thermal stability by TGA was improved after CO addition. Addition of CO to alginate resulted in better mechanical properties when compared with neat alginate. The water vapour permeability was significantly reduced (p 0.05) after CO incorporation. The antibacterial study proved a significant inhibitory effect of the films towards Gram-positive bacteria while no effect was observed for Gram-negative bacteria.

Novel bioactive edible films based on sodium alginate (A) and chitosan biguanidine hydrochloride (CG) with different weight percents were successfully prepared. 13C NMR and 1H NMR confirmed the successful guanidylation of chitosan. Fourier transform infrared confirmed the successful reaction between CG and A. The interaction between CG and A was confirmed through the reduction of the crystalline peaks of both CG and A as detected from their wide-angle X-ray diffraction. Thermogravimetric analysis confirmed that CG enhanced the thermal stability of films as detected from the calculated integral procedure decomposition temperature (IPDT) values. CG incorporation improved the mechanical properties of dry and wet samples. A/CG films exhibited a reduced water vapor permeability and good color properties. The antibacterial study proved that the prepared films showed a remarkable antibacterial killing ability. These results revealed that A/CG films could be an alternative candidate to be used as antibacterial edible films in food industries.

Water pollution with toxic dyes threatens human health world-wide. Herein, we prepared an effective adsorbent hydrogel for removing toxic cationic crystal violet (CV) dye from its aqueous solutions using biodegradable polymers such as; xanthan gum (XG) and poly (N-vinyl imidazole) (PVI). The structure and morphology of the prepared XG/PVI hydrogel and CV loaded hydrogel were characterized by FTIR, FE-SEM and XRD, while thermal stability of investigated hydrogel was characterized by TGA. Adsorption experiments were carried out as functions of initial concentration of CV dye, the adsorbent dose, pH of solution, temperature, and contact time. Results were analyzed using Langmuir and Freundlich isotherm models. It is found that the data were well fitted by Langmuir model. The maximum adsorption capacity achieved was found to be 453 mg g−1 due to electrostatic, H-bonding and dipole–dipole interactions between adsorbent surface and CV molecules. The adsorption kinetic studies showed that the adsorption followed pseudo-first order and intraparticle diffusion kinetic models. Regeneration (desorption) studies showed that XG/PVI hydrogel is an interesting adsorbent for removing toxic dyes from waste water.

Graft copolymerization of chitosan (Ch) with acrylonitrile (AN) prepared by free radical polymerization using potassium persulfate (PPS) as initiator. Optimization of Graft copolymerization of acrylonitrile on to chitosan was performed by studying the main parameters that affecting the grafting process such as initiator and monomer concentrations, reaction time and temperature of the polymerization process to study their influence on percent grafting (G%), grafting efficiency (GE%) and percent homopolymer (H%). Modification of grafted chitosan was done by Schiff’s base derivatives using different aldehydes. They are characterized by FT-IR, X-ray diffraction, thermal analysis and scanning electron microscope. Their antibacterial activities against Streptococcus pneumonia (RCMB 010010), Staphylococcus aureus (RCMB 010028), as Gram-positive bacteria and Escherichia coli (RCMB 010052) as Gram-negative bacteria and the antifungal activity against Aspergillus fumigatus (RCMB 02568), Candida albicans (RCMB 05036) and Geotricum candidum (RCMB 05097) were examined using the diffusion agar technique. The obtained data proved that modified chitosan by grafting show better antimicrobial activities than Chitosan. Also Schiff base derivatives showed better antimicrobial activities than grafted chitosan.

A novel type of reference material has been prepared and characterized for smoke density chamber calibration in the flame condition by Fire Protection Laboratory, National Institute of Standards, Egypt. The new reference material was fabricated by mixing modified magnesium hydroxide nanoparticles (MH-NP-OP) with acrylonitrile–butadiene–styrene copolymer (ABS). The reference material was certified for the physical properties of maximum specific optical density (Dm) and corrected maximum specific optical density (Dm·corr) using the analysis of two different competent laboratories. Preparation, characterization, homogeneity testing and certified value assignment for the developed reference material have been studied. It was clearly demonstrated that the smoke measurement of the two laboratories are harmonic which is an obvious prerequisite for the confidence assessment of the reference material. A metrological approach was followed to detect the statistical biases between different laboratories data to achieve an appropriate accuracy in smoke measurements. The obtained measurement results were statistically analyzed and the certified values of Dm and Dm·corr for reference material were estimated as 510.35 and 472.95, respectively as well as their expanded relative uncertainties at confidence level 95% were recorded 2.78 and 2.7%, respectively. The developed reference material are expected to be used to assist in validating smoke measurements of different materials to realize their fire hazard when be used in building.

Xanthan gum (XG) is natural polysaccharides used in food industries as stabilizers and thickener agents. The problem is that some food products are found to be contaminated by pathogenic bacteria such as Escherichia coli (E. coli) and Staphyloccus aureus (S. aureus) that reduce their shelf life. This research aims to synthesize biodegradable antibacterial XG-grafted-poly(N-vinyl imidazole) PVI and the effect of reaction parameters were studied on grafting yield (G), grafting efficiency (GE), total conversion (TC) and homopolymer (H) %. XG-g-PVI was characterized via various analysis tools. Thermal analysis showed that grafted XG was more thermally stable than unmodified XG and their stability increased with increasing PVI%. XG-g-PVI was acting as antibacterial agent against (E. coli and S. aureus) bacteria that cause food borne diseases. Their activity increases with increasing grafting yield%. Surface morphology showed change from irregular lobules shape in XG to smooth surface in its graft with PVI.

Purpose The purpose of this paper is to prepare cheap and environmentally friendly water soluble polyester coatings through the glycolysis of poly(ethylene terephthalate) (PET) waste. Design/methodology/approach A secondary value-added polyester coatings were prepared from PET waste. The first step was the de-polymerisation of PET waste by 2,2-dimethyl-1,3-propanediol with different molar ratios in the presence of different concentrations of zinc acetate as trans-esterification catalyst. The de-polymerised product was characterised by Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (1HNMR), differential scanning calorimetry and hydroxyl values. The polyesters were successfully synthesised by esterification of the glycolysed product with adipic acid, isophthalic acid, 2,2-dimethyl-1,3-propanediol and trimellitic anhydride in different ratios. FTIR and 1HNMR were used qualitatively and quantitatively to elucidate the structure of the prepared polyesters. Hydroxyl value and the physical properties of the prepared polyesters were also investigated. Two different curing agents were used to prepare the coatings based on the prepared polyesters. Findings Useful coating products were obtained by chemical (glycolysis) of post consumed PET wastes. The 2,2-dimethyl-1,3-propanediol was found to be good glycol in the glycolysis of PET. It was noticed that the rate of glycolysis increases with increasing the amount of catalyst, time of glycolysis and amount of 2,2-dimethyl-1,3-propanediol. N,N-Dimethylethanol amine was a good neutralising agent used for the preparation of water soluble coatings based on glycolysed product of PET. Practical implications The use of waste products like PET waste in water soluble coating systems will bring down the costs of the coatings and will also open a new market of recycled plastic materials and, hence, may provide a potential solution to the problems of solid waste management. It is an attractive option for environmentally friendly and efficient disposal of plastic waste. Originality/value The paper provides a potential way to use undesirable PET waste as industrial raw material. The coatings prepared are eco-friendly, soluble in water that can replace other expensive polyester coatings that are soluble in organic solvents and not environmentally coatings.

Gelatin-g-PAN nanoparticles were successfully synthesized through multisteps preparation. First, polyacrylonitrile with chloride end function was prepared using single electron transfer-living radical polymerization technique. The prepared PAN-Cl was characterized using FT-IR, 1H-NMR and viscosity measurements. Second, the prepared PAN-Cl was grafted onto gelatin. The grafted copolymers were characterized using FT-IR and 1H-NMR spectroscopy and its solubility was examined in different solvents. The grafted copolymer Gel-g-PAN prepared showed high thermal stability as compared with native gelatin. Third, nanoparticles formation was done using nanoprecipitation technique and the prepared nanoparticles were confirmed using transmission electron microscope. Some applications were made onto the fabricated nanoparticles as encapsulation of hydrophobic model, metal ions adsorptions and dyes uptake. Nanoparticles showed high encapsulation efficiency of hydrophobic model. Nanoparticles based on Gel-g-PAN had high ability to absorb transition metal ions than unmodified gelatin and showed high adsorption of basic dyes than acidic dyes.

Purpose This paper aims to study the role of organobentonite (OB) as a filler to improve the mechanical strength of styrene butadiene rubber (SBR). Organoclay was first prepared by modifying bentonite with different concentrations of N-cetyl-N, N, N-triethyl ammonium bromide. A series of SBR composites reinforced with OB were prepared using master-batch method. Design/methodology/approach The curing characteristics, mechanical properties, thermal behavior, dielectric properties and morphology of SBR/OB composites were investigated. Findings The elastic modulus and tensile strength of composites were increased by inclusion of OB, while the elongation at break was decreased, due to the increase in the degree of cross-linking density. Thermal gravimetric analysis revealed an improvement in the thermal stability of the composite containing 0.5 cation exchange capacity (CEC) OB, while the scanning electron micrographs confirmed more homogenous distribution of 0.5CEC OB in the rubber matrix. Also, SBR/0.5CEC OB showed low relative permittivity and electrical insulating properties. Research limitations/implications Bentonite has been recognized as a potentially useful filler in polymer matrix composites because of their high swelling capacity and plate morphology. Practical implications OB improves the cured rubber by increasing the tensile strength and the stiffness of the vulcanizate. Social implications Using cheap clay in rubber industry lead to production of low cost products with high efficiency. Originality/value The clay represents a convenient source because of their environmental compatibility. The low cost and easy availability make the modified clay used as fillers in rubber matrices, and the resultant composites can be applied in variety industrial of applications such as automobile industries, shoe outsoles, packaging materials and construction engineering.

Physically crosslinked hydrogels resulted from interaction between N,N,N-trimethyl chitosan chloride (N-Quaternized Chitosan) (NQC) and poly(acrylic acid) (PAA) were synthesized in different weight ratios (3:1), (1:1) and (1:3) taking the following codes Q3P1, Q1P1 and Q1P3, respectively. Characterization of the mentioned hydrogels was done using several analysis tools including; FTIR, XRD, SEM, TGA, biodegradation in simulated body fluid (SBF) and cytotoxicity against HepG-2 liver cancer cells. FTIR results proved that the prepared hydrogels were formed via electrostatic and H-bonding interactions, while XRD patterns proved that the prepared hydrogels -irrespective to their ratios- were more crystalline than both matrices NQC and PAA. TGA results, on the other hand, revealed that Q1P3 hydrogel was the most thermally stable compared to the other two hydrogels (Q3P1 and Q1P1). Biodegradation tests in SBF proved that these hydrogels were more biodegradable than the native chitosan. Examination of the prepared hydrogels for their potency in heavy metal ions removal revealed that they adsorbed Fe (III) and Cd (II) ions more than chitosan, while they adsorbed Cr (III), Ni (II) and Cu (II) ions less than chitosan. Moreover, testing the prepared hydrogels as antibacterial agents towards several Gram positive and Gram negative bacteria revealed their higher antibacterial activity as compared with NQC when used alone. Evaluating the cytotoxic effect of these hydrogels on an in vitro human liver cancer cell model (HepG-2) showed their good cytotoxic activity towards HepG-2. Moreover, the inhibition rate increased with increasing the hydrogels concentration in the culture medium.

Different samples of sodium alginate grafted by polyacrylonitrile copolymer were synthesized via the grafting process through a free radical polymerization mechanism. Graft structures were characterized and confirmed using Fourier Transform Infrared (FT-IR) spectroscopy and X-Ray diffraction (XRD). Thermogravimetric analysis (TGA) showed that the graft copolymers acquired higher thermal stability compared to native alginate. Moreover, its solubility in several solvents was examined as compared to that of native alginate. The main outcome of this paper was that a grafted copolymer with hydrophobic enrichment (Wt% = 150 %) of polyacrylonitrile as a core was sufficient to form stabilize colloidal system within nanoparticles have Z-average diameter equal 55 nm and sodium alginate as a shell. The SA-g-PAN graft copolymer showed a higher degree of swellability in the basic medium than in acidic medium. The consequence of that was the SA-g-PAN graft copolymer exhibited pH-responsive properties. Moreover, the formed nanoparticles were loaded by a hydrophobic model and proofed by a transmission electron microscope (TEM).

Crosslinked carboxymethyl chitosan (CMCh)/poly(ethylene glycol) (PEG) nanocomposites were synthesized using terephthaloyl diisothiocyanate as a crosslinking agent, in presence of montmorillonite (MMT), in different weight ratios of the two matrices. Characterization of nanocomposites was performed using different analyses. Swelling behavior was studied in different buffered solutions. It was found that formation of crosslinked CMCh/PEG nanocomposites increased the swell ability. Metal ions adsorption had also been investigated. The results indicated that crosslinked CMCh adsorbs various metal ions much more than non-crosslinked CMCh. Antimicrobial activity was examined against Gram-positive bacteria (S. aureus (RCMB 010027) and S. Pyogens (RCMB 010015), Gram-negative bacteria (E. coli (RCMB 010056), and also against fungi (A. fumigates (RCMBA 02564, G. candidum (RCMB 05096) and C. albicans (RCMB 05035). Data indicated that most of these nanocomposites exhibited good antimicrobial potency. Degradation studies were carried out in simulated body fluid for different time periods in order to find out the degradation index. Results showed that weight loss (%) of most of the nanocomposites increased as a function of incubation time.

Chitosan biguanidine hydrochloride (ChG) and glutaraldehyde cross-linked chitosan biguanidine (CChG) were synthesized and characterized by Fourier transform infrared spectroscopy, 1H NMR and 13C NMR, X-ray diffraction, scanning electron microscopy (SEM) and thermal analyses (TGA and DTA). The results showed that ChG and CChG had a more amorphous structure than that of chitosan, and their thermal stability were slightly lower than that of chitosan. Colloidal silver nanoparticles (AgNPs) were prepared using borohydride reduction method and then investigated as fillers in partially cross-linked chitosan biguanidine. The obtained nanoparticles were uniform and spherical with average size of 9.6 ± 0.5 nm. The prepared CChG/AgNPs composites were characterized for their morphology, thermal properties, cytotoxicity and antimicrobial activity. The SEM images showed that the AgNPs are well imbedded in the CChG matrix. The thermal stability of CChG was improved with incorporation of AgNPs. The CChG and CChG/...

A series of copoly(ether-ester-urethane)s have been synthesized from poly(3-hydroxybutyrate) (PHB) diol prepolymer, as hard segments, and copoly(e-caprolactone-ethylene glycol-e-caprolactone) (PCL-PEG-PCL) diols with different PEG block lengths, as soft segments, with/without chitin whiskers (ChW) using hexamethylene diisocyanate, as a coupling agent, in one-step polymerization. The PHB content in the resulting copolymers was 0 and 40 %, and the content of ChW was varied from 0 to 5 %. The chemical structure of the resulting copolymers was characterized by FTIR, 1H-NMR and 13C-NMR spectra. The effect of chemical structure and ChW content on the thermal properties was studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TG). The DSC data revealed that the ΔH m of both PHB and PCL-PEG-PCL slightly increases with increasing the ChW content. The cold and melt crystallization of PHB enhanced with increasing ChW content. The TG data revealed that the thermal stability of copolymers slightly enhanced at high content of ChW. The swelling behavior of the copolymers was also investigated.

This study presents new smart eco-friendly and environmentally acceptable conducting polymer composites. These composites represent high efficient anti-corrosive coatings based on (toluidines and phenylenediamines) /BaSO4 polymer composites for steel protection. These polymer composites were prepared by in-situ chemical oxidative polymerization of (ortho, meta or para) toluidines and phenylenediamines monomers each alone in the presence of BaSO4 extender pigment. The polymerization process was carried out using ammonium peroxydisulphate as an initiator at 0-5 °C. The prepared composites were characterized using spectrophotometric measurements (FTIR, XRD, EDX, SEM), in addition to thermal analysis (DSC & TGA). Small doses of these composites (not exceed 2%) were incorporated into powder coating formulations. The coating formulations including the (toluidines or phenylenediamines / BaSO4) polymer composites were evaluated as corrosion inhibitors. The coated steel panels were examined in a salt spray cabinet for 1500 h with a continuous follow up every 200-300 h. The coating formulations containing conducting polymer/BaSO4 composites achieved impressive and high performance effect in protecting steel panels from corrosion compared with the blank sample. Moreover, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization results also confirmed the high performance corrosion protection properties of polyester/epoxy/conducting polymers/BaSO4 hybrid composites.

The present work focuses on exchanging the sodium in Na-bentonite by single (Mg, Zn and Sr) and double (Zn–Mg, Mg–Sr and Zn–Sr) cations to induce the cation-exchange process. Different cation-exchange bentonites (CEBs) were used as reinforcing fillers with different loadings in acrylonitrile–butadiene rubber (NBR) composites. Curing characteristics, mechanical properties, morphology and swelling behaviour were determined. The study revealed that the performances of Mg bentonite and Mg–Sr bentonite were the best among the tested groups, while Sr bentonite showed the least performance, indicating that addition of Mg deteriorates the reinforcing efficiency of Sr. Moreover, it was observed that the preparation of some CEBs co-intercalated with a surfactant (cetyl trimethyl ammonium bromide (CTAB)) using cation-exchange process was done, and in this part there was a focus on the effect of CTAB surfactant content ratio (0.5CEC) on the CEBs and their influence on the properties of NBR composites.

New and facile method for the synthesis and modification of magnesium hydroxide nanoparticles has been developed. The organic phosphate was used to facilitate the synthesis and wrapping of magnesium hydroxide nanoparticles with organic phosphate shell. The size of the nanoparticles wrapped with phosphate has an average diameter range from 46 to 125 nm. The preparation method has governed the nanoparticles diameter based on reaction time. Thermal stability and morphological properties of the new nanoparticles coated phosphates were investigated. The developed magnesium hydroxide nanoparticles-organic phosphate achieved a very good compatibility when dispersed in acrylonitrile-butadiene styrene polymer (ABS) produced dispersed nanocomposites. The flammability and thermal properties of the new polymer nanocomposites were studied. The rate of burning of the nanocomposites was reduced to 9.8 mm/min compared to 15, 21.9 and 42.5 mm/min for polymer-conventional magnesium hydroxide composite, polymer-conventional magnesium hydroxide-organic phosphate composite and virgin polymer, respectively. The peak heat release rate (PHRR) and total heat release (THR) of the new nanocomposites were recorded as 243.4 kW/m2 and 19.2 MJ/m2, respectively, achieved 71% reduction for PHRR and 55% for THR. The synergism between magnesium hydroxide nanoparticles and organic phosphates shell was also studied. The developed nanoparticles suppressed the emission of toxic gases. The different materials were characterized using thermal gravimetric analysis, fourier transform infrared spectroscopy, transmission electron microscopy. The flammability properties were evaluated using UL94 horizontal method and cone calorimeter. The dispersion of magnesium hydroxide nanoparticles-organic phosphate in ABS was studied using scanning electron microscope.

The curing kinetics of the modified triglycidyl isocyanurate (TGIC) with various content of N-phenylmaleimido group and carboxylated polyester (CPE) was investigated using dynamic differential scanning calorimetry (DSC). The curing kinetic behavior was well described by Sestak–Berggren (SB (m, n)) model. The m order of the curing reaction was varied from 0.229 to 0.356 and n order varied from 1.278 to 2.035, depending on the PMI content. In addition, the isoconversional method of Kissinger–Akahira–Sunose (KAS) was applied to correlate the activation energy (Ea) with the extent of cure. The obtained Ea increased with increasing phenyl maleimide content. As α increases, Ea declined up to α ≈ 0.3, then remained almost constant for α ≈ 0.3–0.8, and finally increased until completion of reaction, indicating complex reaction mechanism. The thermal stability of the cured modified TGIC/CPE was enhanced with incorporation of phenyl maleimide.

Hydrogels composed of N-quaternized chitosan (NQC) and poly(vinyl alcohol) (PVA) in different weight ratios (1:3), (1:1) and (3:1) chemically crosslinked by glutaraldehyde in different weight ratios – 1.0 and 5.0% – have been prepared. The prepared hydrogels were characterized via several analysis tools such as: Fourier transform IR (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM) and thermogravimetric analysis (TGA). Different applications have been done on NQC/PVA hydrogels including; metal ions uptake, swellability in different buffer solutions (pH: 4, 7 and 9), swellability and degradation studies in simulated body fluid (SBF) solutions and antimicrobial activity towards bacteria and fungi. The results indicated that crosslinked NQC/PVA hydrogels with glutaraldehyde (GA) are more thermallystable than non crosslinked hydrogels, NQC/PVA hydrogels swell highly in different buffer solutions as PVA content increases and the antimicrobial activity of NQC/PVA hydrogels is higher than NQC itself.

Hyperbranched polymers/montmorillonite clay modified with cetyl trimethyl ammonium bromide (MMT-CTAB) nanocomposites with polystyrene core were prepared by self-condensing vinyl polymerization via atom transfer radical polymerization of p-chloromethyl styrene monomer (CMS) alone or with styrene (St) and methyl methacrylate (MMA) monomers in the presence of MMT-CTAB acting as inimer with the double bond at one end and the alkyl-Cl unit at the other end. Three hyperbranched polymers/MMT-CTAB nanocomposites such as PCMS homopolymer/MMT-CTAB, PCMS-b-PSt copolymer/MMT-CTAB and PCMS-b-PSt-b-PMMA terpolymer/MMT-CTAB were prepared. The prepared hyperbranched polymers/MMT-CTAB nanocomposites were characterized via X-ray diffraction, dynamic mechanical thermal analyses and transmission electron microscopy for further applications as dielectric materials. Accordingly, several parameters were measured including dielectric permittivity (e′), A.C. conductivity (σ) and loss tangent (tan δ) in case of frequency and temperature ranging from 0.1 Hz to 100 kHz and 20–80 °C, respectively.

Purpose – The purpose of this paper is to evaluate the efficiency of organobentonite (OB) as reinforcing filler in acrylonitrile-butadiene rubber (NBR). The composites were prepared using different loadings of OB and studying in details their properties. A series of OB was modified using surfactant N-cetyl-N, N, N-trimethyl ammonium bromide (CTAB) with concentrations 0.5, 1 and 2 cation exchange capacity (CEC) of bentonite. Design/methodology/approach – The different bentonites were characterized using different analytical and spectro-photometric techniques, such as infra red, X-ray diffraction, thermogravimetric analysis and scanning electron microscopy, while rubber vulcanizate rheological, morphological, swelling and thermal properties were examined using different standard instrumental testing and methods. Findings – The study revealed that the modification of bentonite using CTAB showed significant enhancement on NBR properties, and the optimum filler loading was 12 phr for both 0.5CEC OB and 2CEC OB. These modified bentonites improved reinforcing properties to NBR vulcanizates. Also, results showed that composites exhibited remarkable improvements in tensile strength, elongation at break and hardness in the presence of modified bentonite and also an increase in thermal stability. Research limitations/implications – Na-B cannot be applied in rubber matrix without modification because it is incompatible with it. Practical implications – The modified bentonite is considered as efficient reinforcing filler which can replace other fillers because it has lower surface energy and improved intercalating behaviour in rubber matrix. Originality/value – These papered bentonites are cheap with relatively high purity, which make rubber/clay composites emerge as new class of material and can be used in different fields other than rubber.

Aim of the present study is to investigate synthesis of novel hydrogel as a potential protein carrier, intended for controlled release formulation. The hydrophilic bovine serum albumin (BSA) was chosen as a model protein to be encapsulated within xanthan gum (XG)/poly (N‑vinyl imidazole (PVI) hydrogel. Both XG/PVI hydrogel and XG/PVI/BSA matrix structures were elucidated via different analysis tools such as FTIR, XRD, FE-SEM and EDX. Both BSA loading and release profiles were determined. Cytotoxicity of XG/PVI hydrogel was investigated against normal cell line (VERO cells). The obtained results revealed that % Drug (BSA) loading (% DL) and Encapsulation Efficiency (% EE) increased with increasing both gelation time and loaded BSA concentration, while %DL and %EE decreased with increasing the polymer concentration. The maximum value of %DL and %EE was 59.50% and 99.17%, respectively. Results of in-vitro BSA release in PBS showed that increase in the polymer (XG and PVI) concentrations led to increase in BSA release. Kinetic studies of the in-vitro release of BSA from XG/PVI/BSA matrix followed non-Fickian and case II transport mechanism. Moreover, Cytotoxicity results showed good biocompatibility of this novel hydrogel. SDS-PAGE analysis confirmed that the structural integrity of BSA was not affected by the encapsulation or release conditions. Consequently, this novel hydrogel can be used as an efficient BSA carrier for protein delivery.

Great progress has been devoted recently in the applications of conducting polymers and their composites in corrosion protection of metals by coatings. The ultimate goal of this study is to formulate anti-corrosive hybrid epoxy/polyester and polyester powder coating composites based on phosphate pigments containing poly-o-aminophenol for corrosion protection of steel. The formulations were prepared in two steps. The first step involved In situ emulsion polymerization of o-aminophenol in presence of some phosphate pigments (mainly zinc phosphate, Ca phosphate and Ca–Zn phosphates) via chemical oxidation process using ammonium peroxydisulphate. The second step involved the formulation of the various ingredients of the powder coating composites using hybrid epoxy/polyester and polyester as binders with various doses of phosphate pigments and other inorganic pigments and fillers. The prepared powder coating composites were applied on a cold rolled steel panels and were investigated for physico-mechanical properties and evaluated for their corrosion protection properties via salt spray chamber for 1000 h. The obtained results showed high performance anti-corrosive powder coatings formulations for steel protection.

In our study, we aimed to synthesize novel grafted hyaluronic acid with cationic biodegradable polymer, poly (N-vinyl imidazole) (PVI), through free radical polymerization using potassium persulfate as initiator. The effect of various grafting factors including initiator and monomer concentrations, reaction time and temperature was studied on the percentage of grafting parameters such as; graft yield (% GY), grafting efficiency (% GE) and amount of homopolymer formation (% H). Maximum grafted HA was% GY = 235% and%GE = 83% obtained on optimum conditions at [In] = 17.5 mmol L−1, [M] = 1.25 mol L−1, Temp. = 50 °C, time = 1.5 h and [HA] = 0.025 mol L−1. The structure of grafted HA (HA-g-PVI) was elucidated via various analysis tools such as; elemental analyses, FTIR, 1H NMR, XRD, TGA and Field emission scanning electron microscopy (FE-SEM). Hepatic and breast cancers are two common cancer types threatening people worldwide, so, the antitumor activity of two grafted HA samples (% GY = 155% and 235%) was studied against hepatic cancer (HepG-2) and breast cancer cell lines (MCF-7) compared to unmodified HA and PVI. The results showed that antitumor activity of grafted samples was more than unmodified HA and increased with increasing the grafting percentage of PVI onto HA chains, also, the antitumor activity of tested samples against HepG-2 cell lines was higher than MCF-7 cell lines.

The present study is imported to solve two critical problems we face in our daily life which are microbial pollution and colon cancer. One pot green synthesis of a water soluble polyelectrolyte complex (PEC) between cationic polysaccharide as N,N,N-trimethyl chitosan chloride (TMC) and anionic polymer as poly (acrylic acid) (PAA) in presence of silver nanoparticles to yield (TMC/PAA/Ag) nanocomposites with different Ag weight ratios. Structure of TMC, PAA and TMC/PAA (PEC) were proved via different analysis tools. TMC/PAA and its Ag nanocomposites are used as antimicrobial agents against different pathogenic bacteria and fungi to solve microbial pollution. TMC/PAA-Silver nanocomposites had the highest antimicrobial activity which increases with increasing Ag %. Cytotoxicity data confirmed also that TMC/PAA/Ag (3%) had the most cytotoxic effect (the less cell viability %) towards colon cancer. TMC/PAA (PEC) was formed through electrostatic interactions between N-quaternized (-N+R3) groups in TMC and carboxylate (-COO−) groups in PAA.

The aim of the present work was to study the use of cellulose nanocrystals (CNC) and chitosan nanoparticles (CHNP) for developing controlled-release drug delivery system of the anti-hyperglycemic drug Repaglinide (RPG). CNC was isolated from palm fruit stalks by sulfuric acid hydrolysis; the dimensions of the isolated nanocrystals were 86–237 nm in length and 5–7 nm in width. Simple and economic method was used for the fabrication of controlled release drug delivery system from CNC and CHNP loaded with RPG drug via ionic gelation of chitosan in the presence of CNC and RPG. The prepared systems showed high drug encapsulation efficiency of about ~98%. Chemical modification of CNC by oxidation to introduce carboxylic groups on their surface (OXCNC) was also carried out for further controlling of RPG release. Particles size analysis showed that the average size of CHNP was about 197 nm while CHNP/CNC/RPG or CHNP/OXCNC/RPG nanoparticles showed average size of 215–310 nm. Compatibility studies by Fourier transform infrared (FTIR) spectroscopy showed no chemical reaction between RPG and the system's components used. By studying the drug release kinetic, all the prepared RPG formulations followed Higuchi model, indicating that the drug released by diffusion through the nanoparticles polymeric matrix.

Polycondensation adducts formed by the reaction of maleic anhydride with some Polyalcohols, namely, phloroglucinol, glycerol, and ethylene glycol, were prepared, characterized, and investigated as photostabilizers for polystyrene. Their Photostabilizing effectiveness was evaluated by measuring the extent of weight loss (%), the amount of gel formed as well as the viscosity average molecular weight of the soluble fractions of the degraded polymer. The results indicated better stabilizing effects of these stabilizers compared with that of the UV absorber, phenyl salicylate. A synergistic effect was achieved when the investigated photostabilizers were mixed with phenyl salicylate in a weight ratio of 1:1, and a radical mechanism is proposed to account for the action of the polycondensation adducts as photostabilizers. J. VINYL ADDIT. TECHNOL., 19:293–301, 2013. V C 2013 Society of Plastics Engineers

Some condensation maleic diamide adducts were prepared, characterized, and evaluated as photostabilizers for polystyrene. The potency of these diamides was determined by measuring the extent of weight loss (%), formed gel as well as the average molecular weights M ¯ V of the soluble fractions of the degraded polymers. The results indicated a good stabilizing effect of these products compared with the commercial UV absorber, phenyl salicylate. FTIR spectra of both neat and photoirradiated stabilized polystyrene gave an explanation of some photodegraded products of polystyrene. A probable radical mechanism is proposed to account for the stabilizing action of the diamide derivatives as photostabilizers.

Chelating copolymers (CCPs) bearing carboxylic acid and/or carboxylate moieties based on ethyl methacrylate in the absence and in the presence of divinyl benzene as a crosslinker were prepared via new emulsion copolymerization route. The obtained CCPs were characterized by (FT-IR, 1HNMR, TEM, GPC, and TGA). Furthermore, the prepared CCPs have been tested as adsorbents for various toxic heavy metal ions. They showed higher sorption capacities toward transition metal ions such as (Co(II) and Ni(II)) and much less sorption capacity for (Cd(II) and Pb(II)). The optimum conditions for metal ion uptake such as time, pH, and comonomer concentrations of different weight percent (wt%) as well as the sorption kinetics were investigated. A high recovery about 90–93 % was obtained using HCl as an eluent agent.