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151.
M. A. Hegazy S. S. Abd El‐Rehim E. A. Badr W. M. Kamel Ahmed H. Youssif 《Journal of surfactants and detergents》2015,18(6):1033-1042
Corrosion inhibition of three new synthesized cationic surfactants, N‐(2‐(((Z)‐4‐(pyridin‐4‐yl)but‐3‐en‐1‐yl)amino)ethyl)‐N‐(2‐((E)‐(pyridin‐4‐ylmethylene)amino)ethyl)dodecan‐1‐aminium bromide I(4N), N1,N2‐didodecyl‐N1‐((Z)‐4‐(pyridin‐4‐yl)but‐3‐en‐1‐yl)‐N2‐(2‐((E)‐(pyridin‐4‐ylmethylene)amino)ethyl)ethane‐1,2‐diaminium bromide II(4N) and 1‐dodecyl‐4‐((E)‐((2‐(dodecyl(2‐(dodecyl((Z)‐4‐(1‐dodecylpyridin‐1‐ium‐4‐yl)but‐3‐en‐1‐yl)ammonio)ethyl)ammonio)ethyl)imino)methyl)pyridin‐1‐ium bromide IV(4N) on carbon steel was investigated by weight loss, electrochemical impedance spectroscopy and polarization measurements. Results show that the synthesized cationic surfactants inhibit corrosion of carbon steel in 1 M HCl. The inhibitive action occurs by virtue of adsorption on the metal surface following a Langmuir adsorption isotherm model. Polarization curves reveal that the investigated cationic surfactants can be classified as mixed inhibitor types. The variations in the corrosion inhibition efficiency between three cationic surfactants are correlated with their chemical structures, with more hydrophobic surfactants yielding higher inhibition efficiency. 相似文献
152.
Polymer‐Cationic Surfactant Interaction: 1. Surface and Physicochemical Properties of Polyvinyl Alcohol (PVA)‐S‐Alkyl Isothiouronium Bromide Surfactant Mixed Systems
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Nabel A. Negm Amouna S. Mohamed Sahar M. Ahmed Mohamed Abd El-Raouf 《Journal of surfactants and detergents》2015,18(2):245-250
Surface properties of polyvinyl alcohol (nonionic polymer) and three synthesized cationic surfactants, namely, S‐alkyl isothiouronium bromide at different mole fractions of 1:9, 3:7, 5:5, 7:3, and 9:1, were investigated. The values of the surface parameters were discussed according to the type of interaction between the cationic surfactant and type of polymer studied. The S‐alkyl isothiouronium bromide surfactant molecules are positively charged molecules, and the PVA chains contain hydroxyl groups that are partially negatively charged centers. The comparison between the surface properties of the individual cationic surfactants and their mixture with PVA polymer showed that the mixed systems have some advantages over the individual cationic surfactants. 相似文献
153.
Two-Tier,Scalable and Highly Resilient Key Predistribution Scheme for Location-Aware Wireless Sensor Network Deployments 总被引:1,自引:0,他引:1
We propose a probabilistic key predistribution scheme for wireless sensor networks, where keying materials are distributed
to sensor nodes for secure communication. We use a two-tier approach in which there are two types of nodes: regular nodes
and agent nodes. Agent nodes are more capable than regular nodes. Our node deployment model is zone-based such that the nodes
that may end up with closer positions on ground are grouped together. The keying material of nodes that belong to different
zones is non-overlapping. However, it is still possible for nodes that belong to different zones to communicate with each
other via agent nodes when needed. We give a comparative analysis of our scheme through simulations and show that our scheme
provides good connectivity figures at reasonable communication cost by using minimal flooding in key distribution. Moreover,
we show that our scheme is scalable such that no extra overhead in incurred in case of increased number of nodes and sensor
field size. Most importantly, simulation results show that our scheme is highly resilient to node captures. 相似文献
154.
One of the most important applications of chelating and functional polymers is their capability to recover metal ions from their solutions. This study concerns the synthesis of a hydrophilic glycidyl methacrylate (GMA) monomer‐bearing diethanol amine (DEA) chelating group from the reaction of GMA and DEA. The formed adduct (A) was characterized via FTIR and mass spectra and subjected to homopolymerization and binary copolymerization with ethyl methacrylate and butyl methacrylate. The copolymerization process was carried out via a semi‐batch emulsion polymerization technique by using potassium persulphate/sodium bisulphite as a redox pair initiation system and sodium dodecyl benzene sulphonate as an emulsifier at 65°C. The obtained polymers were characterized via FTIR, thermal gravimetric analysis, and UV–VIS. Volume‐average diameters (Dv) in nanoscale range for the prepared polymers were confirmed by transmission electron microscope investigation. It was shown that the obtained nano‐size chelating polymers have a powerful adsorption character toward transition metal ions (Cu+2, Cr+3, Ni+2, and Co+2) and efficient selectivity for Cu+2 and Ni+2 ions at normal pH. The effects of pH, time, and different comonomer feed compositions on the uptake of metal ions were studied. The reaction between the obtained chelating resins and different metal ions was confirmed to be a second‐order reaction. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
155.
Cellulase was immobilized directly on methyl methacrylate‐glycidyl methacrylate copolymer (MMA‐co‐GMA) and methyl methacrylate‐2‐hydroxy ethyl methacrylate copolymer (MMA‐co‐HEMA) by covalent attachment and crosslinking methods. The properties of the immobilized cellulase were investigated and compared with those of the free one. For the assays carried out through crosslinking method at 25°C and pH 7, the retained activities were found to be 91.92% and 74.63%, respectively, for MMA‐co‐GMA and MMA‐co‐HEMA crosslinked with 0.1% of 1‐cyclohexyl‐3‐(2‐morpholino‐ethyl) carbodiimide metho‐p‐toluenesulfonate (CMCT), respectively. The immobilized cellulase had better stability and higher retained activities with respect to pH, temperature, and storage stability than the free one. In the repeated use experiments, the immobilized cellulase using (MMA‐co‐GMA)‐CMCT (0.1%) and (MMA‐co‐HEMA)‐CMCT (0.1%) did not change after 10 and eight times of repeated use and maintained 67% and 62% from their original activities after 25 times, respectively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
156.
Mohd Azlan Hussain Mohamed Kheireddine Aroua Chun-Yang Yin Ramzalina Abd Rahman Noor Asriah Ramli 《Korean Journal of Chemical Engineering》2010,27(6):1864-1867
The solubility of CO2 in single monoethanolamine (MEA) and diethanolamine (DEA) solutions was predicted by a model developed based on the Kent-Eisenberg
model in combination with a neural network. The combination forms a hybrid neural network (HNN) model. Activation functions
used in this work were purelin, logsig and tansig. After training, testing and validation utilizing different numbers of hidden nodes, it was found that a neural network with
a 3-15-1 configuration provided the best model to predict the deviation value of the loading input. The accuracy of data predicted
by the HNN model was determined over a wide range of temperatures (0 to 120 °C), equilibrium CO2 partial pressures (0.01 to 6,895 kPa) and solution concentrations (0.5 to 5.0M). The HNN model could be used to accurately
predict CO2 solubility in alkanolamine solutions since the predicted CO2 loading values from the model were in good agreement with experimental data. 相似文献
157.
Preparation and characterization of flame retardant solvent base and emulsion paints 总被引:1,自引:0,他引:1
In this research solvent base alkyd and emulsion paint formula were made flame retardant (FR) by incorporation of hexachlorodiphosh (V) azane of types (I–III). Elemental analysis was used to characterize the structure of these compounds. These additives are physically incorporated into the paint formula through grinding in a pebble mill until all particulates have a size below 38 μm. Experimental coatings were manufactured on a laboratory scale, applied by brush on wood and steel panels. Results of an oxygen index value indicated that coating with these compounds containing chlorine, nitrogen and phosphorus exhibit very good flame retardant effect when mixed with solvent base alkyd and emulsion paint. The physical, mechanical and corrosion resistance were studied to evaluate the additives drawbacks. The additives did not affect the flexibility and pinholes of paint formula. The gloss and the impact strength were decreased by the additives, the hardness and adhesion resistance increased by the additives. However, corrosion resistance was not significantly changed by these additives. 相似文献
158.
Siddiqui MR Alshehri S Warad IKh Abd El-Salam NM Mahfouz RM 《International journal of molecular sciences》2010,11(9):3600-3609
Kinetic studies for the non-isothermal decomposition of unirradiated and γ-irradiated silver acetate with 10(3) kGy total γ-ray doses were carried out in air. The results showed that the decomposition proceeds in one major step in the temperature range of (180-270 °C) with the formation of Ag(2)O as solid residue. The non-isothermal data for un-irradiated and γ-irradiated silver acetate were analyzed using Flynn-Wall-Ozawa (FWO) and nonlinear Vyazovkin (VYZ) iso-conversional methods. These free models on the investigated data showed a systematic dependence of Ea on α indicating a simple decomposition process. No significant changes in the thermal decomposition behavior of silver acetate were recorded as a result of γ-irradiation. Calcinations of γ-irradiated silver acetate (CH(3)COOAg) at 200 °C for 2 hours only led to the formation of pure Ag(2)O mono-dispersed nanoparticles. X-ray diffraction, FTIR and SEM techniques were employed for characterization of the synthesized nanoparticles. 相似文献
159.
Mahmoud A. Abd El-Ghaffar Nivin M. Ahmed Elham A. Youssef 《Journal of Coatings Technology and Research》2010,7(6):703-713
This work presents a method of preparing single-, double-, and triple-cation ferrite pigments by employing simple chemical
techniques to study their corrosion protection properties. The prepared pigments were characterized using X-ray diffraction
and scanning electron microscopy. All prepared ferrite pigments were evaluated using ASTM methods. Anticorrosive paint formulations
were performed using different prepared pigment loadings. The physico-mechanical and corrosion properties of dry paint films
were examined. The tests revealed that the prepared ferrite pigments show excellent anticorrosive behavior, and that the best
among them in performance are zinc and zinc magnesium. Calcium, zinc–calcium, and zinc–magnesium–calcium ferrites show better
performance in high pigment loadings, while magnesium ferrite pigments show good results only in low pigment loading. 相似文献
160.
Islam Hamdy Abd El Maksod Eman.Z. Hegazy Sayed.H. Kenawy TamerS. Saleh 《Advanced Synthesis \u0026amp; Catalysis》2010,352(7):1169-1178
A green and effective method is reported for the reduction of p‐nitrophenol to p‐aminophenol using a nano‐sized nickel catalyst supported on silica‐alumina in the presence of hydrazine hydrate as an alternative source of hydrogen. It was found that nickel loaded on a silica‐alumina support is a very effective catalyst in the hydrogenation of p‐nitrophenol to p‐aminophenol. Thus it attained 100% conversion in only 69 seconds instead of 260 seconds for commercial Raney nickel. In addition, the possibility to reuse it more than one time with great efficiency gives it another advantage over commercial Rainey nickel which cannot be used more than once. This economical and environmentally friendly method provides a potentially new approach for the synthesis of the intermediate product of paracetamol in industry, which overcomes the drawbacks of the known reduction methods. The prepared catalysts were fully characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X‐ray (EDX), and electron spin resonance (ESR) tehniques. 相似文献