Manar El-Sayed Abdel-Raouf

Propylene oxide-ethylene oxide block copolymers as demulsifiers for water-in-oil emulsions, I. Effect of molecular weight and hydrophilic-lipophylic balance on the demulsification efficiency

SummaryA series of propylene oxide (PO)-ethylene oxide (EO) block copolymers with differentEO/PO ratios and molecular weights have been prepared and tested for their demulsification potency in breaking synthetic water-in-benzene emulsions stabilized by asphaltenes. Their partition coefficients between benzene and water were determined by means of UV absorption. NMR spectroscopic analysis was used for determining the actualPO/EO ratios of these block copolymers. The effects of hydrophilic-lipophilic balance (HLB) and molecular weight of the prepared surfactants on their demulsification efficiency were investigated. It was found that the demulsification efficiency is directly proportional to both HLB and molecular weight.ZusammenfassungEine Reihe von Propylenoxid (PO)-Ethylenoxid (EO) Blockcopolymeren mit verschiedenenEO/PO-Verhältnissen und Molekulargewichten wurden hergestellt und auf ihre Effizienz bezüglich des Brechens von durch Asphalt stabilisierten synthetischen Wasser/Benzol-Emulsionen untersucht. Ihre Verteilungskoeffizienten zwischen Benzol und Wasser wurden mittels UV-Spektroskopie ermittelt. DasPO/EO-Verhältnis wurde NMR-spektroskopisch bestimmt. Die Effekte von Hydrophilie-Lipophilie-Gleichgewicht (HLB) und Molekulargewicht auf die Effizienz der Wirkung wurden untersucht. Das Emulsionsbrechungsvermögen ist direkt proportional zu HLB und indirekt proportional zum Molekulargewicht.

Propylene oxide-ethylene oxide block copolymers as demulsifiers for water-in-oil emulsions, II. Effects of temperature, salinity,pH-value, and solvents on the demulsification efficiency

SummaryThe effects of temperature, NaCl concentration (salinity),pH value, and solvents on the demulsification efficiency of propylene oxide (PO)-ethylene oxide (EO) block copolymers in the breaking of synthetic water-in-benzene emulsions stabilized by petroleum asphaltenes have been thoroughly investigated. The demulsification efficiency of the studied polymeric surfactants was found to increase with increasing temperature and decreasing salinity of the aqueous phase. A neutralpH value of the aqueous phase of the emulsion was found to be optimat for efficient demulsification. Water and water compatible solvents were found to be the best solvents for the prepared demulsifiers with respect to demulsification properties.ZusammenfassungDie Einflüsse von Temperatur, NaCl-Konzentration,pH-Wert und Lösungsmitteln auf die Fähigkeit von Propylenoxid-Ethylenoxid-Blockcopolymeren (PO-EO), durch Asphalte stabilisierte Wasser-in-Benzol-Emulsionen zu brechen, wurden eingehend studiert. Die Wirksamkeit der untersuchten polymeren oberflächenaktiven Substanzen steigt mit steigender Temperatur und sinkendem Salzgehalt der wäßrigen Phase. Am besten verläuft die Demulsifikation bei neutralempH-Wert. Wasser und vergleichbare Lösungsmittel eignen sich am besten zur Erzielung einer hohen Wirksamkeit der verwendeten Emulsionsbrecher.

Polyoxyethylenated bisphenol-A for breaking water-in-oil emulsions

Polyethylene glycol (PEG) of different molecular weights, namely, 600, 1000 and 4000 g/mol was reacted with bisphenol A to form compounds having different hydrophile–lipophile balances and hence different surface activities. The interfacial tension at the aqueous/benzene interface was determined. It was found that the concentrations of demulsifiers required to cause a minimum interfacial tension are always less than those inducing a maximum demulsification efficiency. The demulsification efficiency of the prepared surfactants in breaking synthetic water in benzene emulsions stabilized by petroleum asphaltenes was evaluated. The data revealed that the demulsification efficiency increases with increasing demulsifier concentration, contact time and hydrophilicity.

Synthesis and investigation of hydrogel nanoparticles based on natural polymer for removal of lead and copper(II) ions

AbstractHydrogel nanoparticles were synthesized by graft copolymerization of acrylic acid and N-isopropylacrylamide (NIPA) onto carboxymethyl cellulose (CMC) by inverse microemulsion polymerization. Ethylene glycol dimthacrylate (EGDMA) was used as crosslinker. The structure, morphology, and size of the prepared nanogels were characterized by Fourier transform infrared spectroscopy and transmission electron microscope, respectively. The prepared nanogels were used to remove copper and lead ions from aqueous solutions. The effects of pH, time, crosslinker concentrations, temperature, and initial metal ion concentration on the metal ion removal capacity were investigated.

Cellulose-Based Superabsorbent Hydrogels

Hydrogels are polymeric three-dimensional networks able to absorb and release water solutions. Sometimes, this behavior is reversed in response to definite environmental stimuli, i.e., temperature, pH, ionic strength, etc. Such stimuliresponsive behavior makes hydrogels attractive candidates for the design of “smart” devices, applicable in a variety of technological fields. In particular, when concerning either ecological or biocompatibility issues, the biodegradability of the hydrogel network, combined with the control of the degradation rate, may add more value to the developed device. Development of new products and materials, particularly those which are based on renewable organic resources using innovative sustainable processes, represents an increasing interest in both academic and industrial research. Cellulose and its derivatives – with numerous A. M. A. Hasan · M. E.-S. Abdel-Raouf (*) Egyptian Petroleum Research Institute, Cairo, Egypt e-mail: drmanar770@yahoo.com # Springer International Publishing AG, part of Springer Nature 2018 Md. I. H. Mondal (ed.), Cellulose-Based Superabsorbent Hydrogels, Polymers and Polymeric Composites: A Reference Series, https://doi.org/10.1007/978-3-319-76573-0_11-1 1 hydroxyl groups – have established to be flexible materials with unique chemical structure which provides a good platform for the creation of hydrogel networks with distinctive properties with respect to swelling ability and sensibility to external stimuli. Consequently, cellulose-based hydrogels are attractive materials, biodegradable, biocompatible, and low cost, which exhibit properties that make them promising in many applications, particularly in biomedical and environmental applications. This article reviews the design and the applications of cellulosebased hydrogels, which are extensively investigated due to cellulose availability in nature, the intrinsic degradability of cellulose, and the smart behavior displayed by some cellulose derivatives.