Showing papers on "Distilled water published in 2005"
TL;DR: In this article, a basin-type solar still and a conventional flat-plate collector were connected together in order to study the effect of augmentation on the still under local conditions, where the still inlet was connected to a locally made, fin-tube collector such that its outlet was fed to the still basin instead of the common storage tank.
209 citations
TL;DR: In this article, an aniline-based polymer was electrochemically prepared and applied as a new fiber coating for solid phase microextraction (SPME) of some priority phenols from water samples.
195 citations
TL;DR: In this paper, anionic surfactant-modified alumina (SMA) was used for the removal of crystal violet (CV), a well-known cationic dye from aquatic environment.
192 citations
TL;DR: An inclined solar water distillation system was designed and tested under actual environmental conditions of northern Cyprus as discussed by the authors, where the feed water falls down on the solar absorber plate, and the system produces fresh water and hot water simultaneously.
143 citations
TL;DR: In this article, co-polymeric hydrogels, synthesized by polymerization of acrylamide and sodium acrylate in aqueous medium, have been characterized with respect to their swelling behaviour and structural parameters.
Abstract: In this study, co-polymeric hydrogels, synthesized by polymerization of acrylamide and sodium acrylate in aqueous medium, have been characterized with respect to their swelling behaviour and structural parameters. The gels exhibited appreciable water uptake in distilled water and the swelling exponent has been found to be in the range 0.60–0.80, thus indicating non-Fickian mechanism. The gels demonstrated second-order kinetics as confirmed from the linear nature of the plots obtained by fitting the experimental data to Schott equation. To obtain better model for above 60% water uptake, the Beren–Hopfenberg differential model was applied, which also enabled to calculate the relaxation constants. The value of apparent activation energy for the sample containing 44 percent mole fraction of sodium acrylate was found to be 13.85 kJ mol−1 as determined from the Arrhenius plot, while the sample without sodium acrylate exhibited higher activation energy of 17.00 kJ mol−1. The enthalpy of mixing was determined using the Gibbs–Helmholtz equation. The values of ΔHmix were found to be −0.827 and 1.021 kJ mol−1 for the samples with 44 and 29 percent mol fraction of sodium acrylate. Finally, the swollen gels demonstrated a sharp volume phase transition when put in the solutions of divalent ions, i.e., Ni2+ and Ba2+ ions, thus proving their candidature for being used in removal of toxic divalent ions from their aqueous solutions via divalent–monovalent ion-exchange mechanism.
112 citations
TL;DR: In this paper, the effect of factors influencing the separation of water in oil emulsions was investigated, and it was shown that increasing emulsifier content and decreasing water content feed decrease permeate flux and water content in permeate.
108 citations
TL;DR: In this article, a novel starch-graft-poly(acrylamide)/atta- pulgite superabsorbent composite was synthesized by graft copolymerization reaction of starch, acrylamides (AM), and at- tapulgite micropowder using N.methylene-bisacryamide (MBA) as a crosslinker and ammonium persulphate (APS) as an initiator in aqueous solution, followed by hydrolysis with sodium hydroxide.
Abstract: A novel starch-graft-poly(acrylamide)/atta- pulgite superabsorbent composite was synthesized by graft copolymerization reaction of starch, acrylamide (AM), and at- tapulgite micropowder using N.N-methylene-bisacrylamide (MBA) as a crosslinker and ammonium persulphate (APS) as an initiator in aqueous solution, followed by hydrolysis with sodium hydroxide. The effects on water absorbency, such as amount of crosslinker, initiator, attapulgite, weight ratio of acrylamide to starch in the feed, gelatinization conditions of starch and molar ratio of NaOH to acrylamide, and so forth, were investigated. These superabsorbent composites were characterized by Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). The water ab- sorbencies for these superabsorbent composites in water and saline solution were investigated, and water retention tests were carried out. Results obtained from this study showed that the water absorbency of superabsorbent composite synthe- sized under optimal synthesis conditions with an attapulgite content of 10% exhibit absorption of 1317 g H2O/g sample and 68 gH 2O/g sample in distilled water and in 0.9 wt % NaCl solution, respectively. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1351-1357, 2005
94 citations
TL;DR: The destruction of methyl tert-butylether in water in the presence of chloroform has been studied using 60Co gamma irradiation using a kinetic model incorporating recently determined bimolecular rate constants to describe the destruction of the MTBE and CHCl3 individually and in mixtures.
92 citations
TL;DR: Differential scanning calorimetric study indicated that diclofenac sodium in amorphous form was dispersed in the matrix of DCA beads, and the swelling and water uptake of the beads depended on the properties of incorporated additives.
81 citations
01 Jan 2005-Journal of Environmental Science and Health Part A-toxic\/hazardous Substances & Environmental Engineering
TL;DR: After the adsorption of SDS on alumina, the surfactant-modified alumina (SMA) was used for the removal of crystal violet (CV), a well-known cationic dye from aquatic environment and the removal efficiency was even better for tap water and much better for wastewater when compared to that using distilled water.
Abstract: The adsorption characteristics of sodium dodecyl sulfate (SDS), an anionic surfactant on neutral alumina were studied in detail. Alumina was found to be an efficient adsorbent for SDS and could be used for the removal of SDS from its highly concentrated (several thousand ppm) solution. The equilibrium time found was 2 h. Though the removal efficiency was low (approximately 65%) at neutral pH, but in slightly acidic condition and in the presence of NaCl the efficiency could be increased dramatically (up to >98%). The adsorption isotherm study showed distinct four regions. The effects of various other parameters such as adsorbent dose, time, and the presence of different ions (Cl-, NO3-, SO4(2-), and Fe3+), and nonionic surfactant on the SDS adsorption were also studied. It was observed that the adsorption capacity was increased due to the presence of these ions in general. After the adsorption of SDS on alumina, the surfactant-modified alumina (SMA) was used for the removal of crystal violet (CV), a well-known cationic dye from aquatic environment. The kinetic studies showed that 1 h shaking time was sufficient to achieve the equilibrium. The removal of CV followed the second order kinetics. Studies were conducted to see the effects of adsorbent dose and initial CV concentration on the removal of CV using SMA. The pH was maintained at 6.7+/-0.1. SMA was found to be very efficient, and approximately 99% efficiency could be achieved under optimised conditions for the removal of CV when present even at a high concentration (200 ppm). To test whether the removal of CV was possible from real water using SMA, the adsorption study was conducted using CV spiked samples using distilled water, tap water, and synthetically prepared wastewater. It was interesting to note that the removal efficiency was even better for tap water and much better for wastewater when compared to that using distilled water. Desorption of both SDS and CV from the SMA surface was possible using 1 M sodium hydroxide solutions.
59 citations
TL;DR: The ability of seeds of plants: Phaseolus vulgaris, Robinia pseudoacacia Ceratonia siliqua and Amorpha fruticosa, to act as natural coagulants was tested using synthetic turbid water as discussed by the authors.
Abstract: The ability of seeds of plants: Phaseolus vulgaris, Robinia pseudoacacia Ceratonia siliqua and Amorpha fruticosa, to act as natural coagulants was tested using synthetic turbid water. This water was prepared by adding kaolin into tap water, just before the test. Active components were extracted from ground seeds with distilled water. The coagulation ability of this extract was assessed by the use of standard jar test measurements in water with various initial turbidity. Investigation of these natural coagulants was confirmed their positive coagulation activity. Of all plants that have been examined, the seed extract from Ceratonia siliqua appeared to be one of the most effective coagulants for water treatment. A dose of 20 mg/l of this coagulant resulted in 100% coagulation activity for clarification of water with 17.5 NTU initial turbidity.
TL;DR: In this paper, the authors present the emulsification of Ekofisk crude oil using five biosurfactants (rhamnolipid, tannin, saponin, lecithin and aescin), and a synthetic surfactant (sodium dodecyl sulphate).
TL;DR: In this paper, a poly(acrylic acid)/sodium humate superabsorbent composite was synthesized by aqueous solution polymerization of acrylic acid using N, N'-methylenebisacrylamide as a crosslinker and ammonium persulfate as an initiator in the presence of sodium humate.
Abstract: A novel poly(acrylic acid)/sodium humate superabsorbent composite was synthesized by aqueous solution polymerization of acrylic acid using N, N'-methylenebisacrylamide as a crosslinker and ammonium persulfate as an initiator in the presence of sodium humate. The effects on water absorbency such as initial monomer concentration, degree of neutralization of acrylic acid, amount of crosslinker, initiator and sodium humate, etc. were investigated. The water absorbency of the superabsorbent composite synthesized under optimal synthesis conditions with a sodium humate content of 20% exhibited an absorption of 1268 g H2O/g sample and 93 g H2O/g sample in distilled water and in 0.9 wt% NaCl solution, respectively. Swelling rate and water retention tests were also carried out. The results show that sodium humate, as a kind of functional filler, can enhance comprehensive properties of superabsorbent composite and reduce the product cost significantly. Copyright (c) 2005 John Wiley & Sons, Ltd.
TL;DR: By using reduced number of cashew nuts it was possible to infer about seedling emergence process without violation of the statistical principles and assumptions, and uncertainty values far from zero and values of Z near zero indicated low seedling emerged synchrony for this species.
Abstract: Anacardium humile has low capacity for fruit production, limiting the application of experimental techniques, broadly used in the analysis of seed germination. Thus, the purpose of this paper was to introduce the statistical theory of small samples to the study of the seedling emergence of this species. Cashew nuts of different individuals were randomly collected, being submitted to scarification by abrasion of the pericarp near the pedicel; scarification in the same manner followed by washing in water for 24 hours, and intact cashew nuts as control treatment. The cashew nuts (50 per treatment) were sowed at 1 cm depth, in vermiculite moistened with distilled water at field capacity. The experiment was carried out under continuous fluorescent white lamps (21.8 µmol m-2 s-1), at 25 oC. The emergence (%) presented approximated normal distribution for all treatments and they did not differ significantly by Student t test (emergence between 70% and 76%). Seedlings emerged from scarified cashew nuts washed in water presented shorter mean emergence time (16.3 days) and consequently higher mean emergence rate (0.0613 day1) in relation to the other treatments. The uncertainty values far from zero (I > 3.28 bits) and values of Z near zero (Z < 0.095) indicated low seedling emergence synchrony for this species. The results obtained showed that by using reduced number of cashew nuts it was possible to infer about seedling emergence process without violation of the statistical principles and assumptions.
01 Jul 2005-Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment
TL;DR: In this paper, the surface/volume ratios in the migration cell were set at 8.04 and 10.05 dm2 l(-1) for n-heptane and distilled water, respectively.
Abstract: Migration experiments with polystyrene were performed in two-sided contact with n-heptane and distilled water as the food simulants at temperatures of 10, 24 and 40, and 40, 60 and 90 degrees C, respectively. The surface/volume ratios in the migration cell were set at 8.04 and 10.05 dm2 l(-1) for n-heptane and distilled water, respectively. Styrene monomer, styrene dimers and styrene trimers migrating to the food simulants were determined by GC-FID analysis. Heptane fully extracted the styrene monomer and the oligomers from the polystyrene sheet, whereas in the distilled water only the migrated styrene trimers could be detected. To determine the apparent diffusion coefficient, the migration process was analysed based on Fick's law. The higher the molecular weight of the oligomers, the more significant the reduction in the diffusion coefficient. Higher molecular weight oligomers also had lower activation energy of diffusion when the temperature dependence of diffusivity was analysed by the Arrhenius equation. The diffusion coefficient of the trimers was much higher for heptane contact than for water. The activation energy of the diffusion of trimers for water contact was higher than that for heptane.
TL;DR: In this article, the authors present the status of water desalination in Kuwait, and the limitations of current equipment in satisfying the increased water demand, and give the reasons for the water problem, and present a more efficient and rapidly deployable solution for power and desalinated production.
TL;DR: In this article, the desorption of Pb2+ and Cu2+ from Nypa frutican Wurmb biomass originally loaded with these two metals in a batch adsorption experiment was investigated using acidic, basic and neutral reagents.
Abstract: The desorption of Pb2+ and Cu2+ from Nypa frutican Wurmb biomass originally loaded with these two metals in a batch adsorption experiment was investigated using acidic, basic and neutral desorption solutions. The metal-loaded biomass was treated with 0.1 M HCl, 0.1 M NaOH and distilled water at varying contact time. The data shows that desorption in all the reagent increased with increase in contact time, reaching 75.3 and 63.7% in acid reagent, 18.9 and 14.06% in basic reagent and 3.35 and 2.44% in distilled water for Pb2+ and Cu2+, respectively, at a contact time of 140 min. The desorption kinetic showed that the release constant, kdes, for both metal ion in acidic system was faster (6.3 x 102 and 7. 9 x 102 min-1 for Pb2+ and Cu2+) than other desorption reagents.
TL;DR: In this article, the effect of temperature on the reaction of γ-Al2O3-modified Al powders with distilled water was investigated and it was found that by increasing the temperature up to 40°C, the hydrogen generation speed can be enhanced one to two orders of magnitude relative to that at room temperature (18°C).
Abstract: The effect of temperature on the reaction of γ-Al2O3-modified Al powders with distilled water was investigated. It was found that by increasing the temperature up to 40°C, the hydrogen generation speed can be enhanced one to two orders of magnitude relative to that at room temperature (18°C). X-ray analyses and transmission electron microscopy observations revealed that the reaction by-product at 40°C is bayerite (Al(OH)3), which is chemically neutral. The present results imply that slightly increasing the temperature is an effective way to get the target hydrogen generation speed.
01 Jan 2005
TL;DR: In this paper, the authors reported experimental results relative to the influence of pore fluid composition on liquid limit, compressibility and residual shear strength of three clayey soils: the Ponza bentonite, a commercial bentonite and the Bisaccia clay.
Abstract: Summary This paper reports experimental results relative to the influence of pore fluid composition on liquid limit, compressibility and residual shear strength of three clayey soils: the Ponza bentonite, a commercial bentonite, the Bisaccia clay. Compressibility was evaluated by means of oedometer tests and the residual shear strength was determined by means of direct shear and ring shear tests. The soils were powdered and tested dry and reconstituted with distilled water, salt solutions at various concentrations and organic fluids with different dielectric constants, both lower and higher than that of water. In order to evaluate the influence of pH, some tests were carried out by using HCl solutions. The results show that the effects of so different fluids can be compared directly with reference to their static dielectric constant D. As D increases from 1 to 80, liquid limit and compression index increase and the residual shear strength decreases. The liquid limit of the materials prepared with formamide (D = 110) assumes values very close to those obtained with distilled water, whereas the compression index is slightly lower and the residual shear strength much higher than in water.
TL;DR: It was concluded that, by the presence of small amounts of organic acids, the water-ethanol hydrogen-bonding structure was strengthened, at the same time, the proton exchange between water and ethanol molecules was promoted in shochu, compared with the water/ethanol mixture.
Abstract: The hydrogen-bonding properties of water-ethanol of alcoholic beverages and water-ethanol mixtures of the corresponding ethanol contents were examined on the basis of OH proton NMR chemical shifts and the Raman OH stretching spectra of water and ethanol. Japanese shochu, an unaged distilled spirit of 25% (v/v) alcoholic content made from various grains, was provided for the samples; it is a high-purity spirit as it contains only small amounts of dissolved components, like typical vodka, gin, and white rum. The hydrogen-bonding structure in shochu containing some acids was found to be different from that of the water-ethanol mixture with corresponding ethanol content. It was concluded that, by the presence of small amounts of organic acids, the water-ethanol hydrogen-bonding structure was strengthened, at the same time, the proton exchange between water and ethanol molecules was promoted in shochu, compared with the water-ethanol mixture. The NMR chemical shifts of fruit cocktail drinks suggested that the hydrogen bonding of water-ethanol in the solution was developed by organic acids and (poly)phenols from fruit juices.
TL;DR: Thioacetamide immobilized on silica gel was prepared via the Mannich reaction and adsorption capacity has been found to be 19.76, 16.35, and 12.50 mg/g for Pb, Cu, and Cd(II), respectively, with the preconcentration factor of approximately equal to 300.
Abstract: Thioacetamide immobilized on silica gel was prepared via the Mannich reaction. The extraction and enrichment of copper(II), lead(II), and cadmium(II) ions from aqueous solutions has been investigated. Conditions for effective extraction are optimized with respect to different experimental parameters in both batch and column processes prior to their determination by flame atomic absorption spectrometry (FAAS). The optimum pH ranges for quantitative adsorption are 4.0-8.0, 2.0-7.0, and 5.0-10.0 for Pb(II), Cu(II), and Cd(II), respectively. Pb(II) and Cd(II) can be desorbed with 3 mol/L and 0.1 mol/L HCl/HNO3, and Cu(II) can be desorbed with 2.5% thiourea. The adsorption capacity of the matrix has been found to be 19.76, 16.35, and 12.50 mg/g for Pb(II), Cu(II), and Cd(II), respectively, with the preconcentration factor of approximately equal to 300 for Pb(II) and approximately equal to 200 for Cu(II) and Cd(II). Analytical utility is illustrated in real aqueous samples generated from distilled water, tap water, and river water samples.
TL;DR: In this paper, the authors evaluated the impact of design and operating conditions on nitrate flux and energy consumption for removing nitrate from drinking water using electrodeionization and found that increasing the number of membrane pairs in the unit resulted in a decreased flux but appeared to have little impact on the energy consumed.
TL;DR: In this article, the influence of metal fillers on water/moisture sorption characteristics of adhesives was investigated and it was found that there is no significant effect of aluminum filler content on moisture diffusivity in epoxy adhesive specimens while adding aluminum filler into epoxy decreases the total amount of water intake at saturation.
TL;DR: Although not having all the cell compatibility of collagen, these fully synthetic quaternary ammonium-modified PEO-rich gels may have some utility in tissue-engineering applications where stiff gels and cell attachment after gelation are desired.
Abstract: Four-arm poly(ethylene oxide) and poly(propylene oxide) (PEO-PPO) block copolymer (poloxamine, Tetronic 1107) hydrogels were modified with positively charged groups with the aim of overcoming the low cell adhesion properties of these PEO-rich systems. Different matrices containing poloxamine-methacrylate (6-12%) and a quaternary ammonium methacrylate ([2-(methacryloyloxy)ethyl]-trimethylammonium chloride [MAETAC], 0-0.48 M) were produced by a photo-initiated free radical copolymerization. A sharp increase in water content for MAETAC-containing gels was seen during the first 2 days of incubation in distilled water; some of the gels showed water uptakes as high as 12 times the initial wet weight. In phosphate-buffered saline (PBS), this effect was less pronounced because of the decrease in the osmotic gradient. In addition, a gradual increase of both the storage and the loss modulus of the gels resulted from increasing the MAETAC content [e.g., G' values increased from 13,500 Pa for 12% poloxamine-methacrylate gels without MAETAC to 151,000 Pa for 0.48M MAETAC contents (at 1 Hz, 100 Pa of oscillatory stress)]. Although on pure poloxamine-methacrylate gels HepG2 and HUVEC cells attached poorly, on MAETAC-containing specimens a well-spread morphology and confluent monolayers were obtained, at least after preincubation in serum containing medium. Although not having all the cell compatibility of collagen, these fully synthetic quaternary ammonium-modified PEO-rich gels may have some utility in tissue-engineering applications where stiff gels and cell attachment after gelation are desired.
Journal Article•
01 Jan 2005-Food Additives and Contaminants Part A-chemistry Analysis Control Exposure & Risk Assessment
TL;DR: In this paper, the surface/volume ratios in the migration cell were set at 8.04 and 10.05 dm2 l(-1) for n-heptane and distilled water, respectively.
Abstract: Migration experiments with polystyrene were performed in two-sided contact with n-heptane and distilled water as the food simulants at temperatures of 10, 24 and 40, and 40, 60 and 90 degrees C, respectively. The surface/volume ratios in the migration cell were set at 8.04 and 10.05 dm2 l(-1) for n-heptane and distilled water, respectively. Styrene monomer, styrene dimers and styrene trimers migrating to the food simulants were determined by GC-FID analysis. Heptane fully extracted the styrene monomer and the oligomers from the polystyrene sheet, whereas in the distilled water only the migrated styrene trimers could be detected. To determine the apparent diffusion coefficient, the migration process was analysed based on Fick's law. The higher the molecular weight of the oligomers, the more significant the reduction in the diffusion coefficient. Higher molecular weight oligomers also had lower activation energy of diffusion when the temperature dependence of diffusivity was analysed by the Arrhenius equation. The diffusion coefficient of the trimers was much higher for heptane contact than for water. The activation energy of the diffusion of trimers for water contact was higher than that for heptane.
01 Jun 2005
TL;DR: In this article, the authors compared hot water and chemical effects on chilling injury of pomegranates and showed that increasing the water temperature to 45°C significantly reduced chilling injury, electrolyte and K + leakage but had no significant effect on total soluble solids, total acidity, ascorbic acid and pH of fruit after removal from storage.
Abstract: In an initial experiment comparing hot water and chemical effects on chilling injury, 'Malas Yazdi' and 'Malas Saveh' pomegranates (Punica granatum) were dipped in hot water at 50 and 75°C, imazalil (1 and 3 ml/L) and benzyladenine (80 and 100 mg/L) for 2 and 5 min. Distilled water at 25°C was used as a control treatment. Treated fruit were stored at 1.5°C and 85±3% RH for 4.5 months. Although water at 75°C resulted in heat injury of fruit, hot water at 50°C compared with the other treatments significantly reduced chilling injury. In a second experiment, 'Malas Yazdi' pomegranates were dipped in hot water at 25 (control), 35, 45, 55 and 65°C for 2 and 5 min. Treated fruit were stored for 3 months under the same conditions as used in the first experiment. The results showed that increasing the water temperature to 45°C significantly reduced chilling injury, electrolyte and K + leakage but had no significant effect on total soluble solids, total acidity, ascorbic acid and pH of fruit after removal from storage.
TL;DR: In this paper, a composite of poly(AN)-starch graft copolymer, homopoly(AN), oxidized starch and unreacted starch was used to obtain high water absorbency.
Abstract: Hydrogels based on saponified products of poly (acrylonitrile, AN)-starch composites were prepared, characterized and their water abosrbency properties examined. The term composite refered to the resultant products of polymerizatin of AN with starch in presence of ceric ammonium nitrate (CAN) as initiator, that is the composite consists of poly(AN)-starch graft copolymer, homopoly(AN) , oxidized starch and unreacted starch. Thus AN monomer was polymerized with gelatinized starch using the ceric ion method. Gelatinization of starch prior to polymerization was affected by heating certain weight of starch in certain volume of distilled water at different temperrature (65, 75 and 85°C). Polymerization was carried out under a variety of coditions. Saponification of poly (AN)-starch composites was performed in sodium hydroxide to yield the hydrogels. The water absorbency properties of these hydrogels were found to rely on variables affecting the magnitudes of both polymerization and saponification. Among these variables mention was made of the starch/liquor ratio, cocentration of ceric ammonium nitrate (CAN), monomer/starch molar ratio, duration of grafting and gelatinization temperature as well as saponification time. Hydrogels display their maximum water absorbency when granular starch was firstly gelatinized at 85°C for 30 min and secondly subjected to polymerization with AN using AN/starch molar ratio of 4.8 and CAN concentration of 10 mmol/L liquor ratio of 12.5 and thirdly sample of the so obtained poly (AN)-starch composite was saponified in sodium hydroxide (0.7 N) at 95°C for 180 min. The saponified product was then precipitated in excess methanol, dried and finally converted into powder. The product (hydrogel) in the powder form exhibited maximum water absorbency of 920 g water per gram hydrogel and 38 mL synthetic urine per gram hydrogel.
TL;DR: In this article, a poly(N-isopropylacrylamide) modified polyurethane (PUNIPAAm) was analyzed by Fourier transform infrared spectroscopy.
TL;DR: It seems that a significant quantity of non-phthalic and phthalic residues diffuse out of the acrylic resin materials examined, and the main component extracted was methyl methacrylate, the level of which seems to be time-dependent and decreases for a period of up to 5 days when resins are stored in distilled water at room temperature.
Abstract: HPLC was used to examine the leachability of three non-phthalic and four phthalic post-polymerized residual monomers from three commercially available heat-cured acrylic resins. Specimens of equal dimensions were constructed from each brand of material by following the standardized procedure and were stored under three different conditions, namely, distilled water, artificial saliva, and a binary mixture of ethanol/water. The resulting liquids provided samples for analysis by HPLC. Three different experiments were performed for each brand of acrylic and each storage condition in order to examine the effects of parameters, particularly time and temperature. The results obtained from this study suggest that a wide spectrum of residues diffuse out of the three examined acrylic resin materials. The non-phthalic compounds were leached at high concentrations, whereas all the phthalates examined exhibited different degrees of elusion commensurate with the storage condition, brand of material, and type of experiment. It seems that a significant quantity of non-phthalic and phthalic residues diffuse out of the acrylic resin materials examined. The main component extracted was methyl methacrylate, the level of which seems to be time-dependent and decreases for a period of up to 5 days when resins are stored in distilled water at room temperature.
TL;DR: In this paper, the authors used microwave irradiation to synthesize a superabsorbent, in which potassium persulfate (PPS) was used as the initiator and polyethyleneglycol diacrylate as the crosslinker.
Abstract: Sodium acrylate was grafted onto cornstarch by microwave irradiation to synthesize a superabsorbent, in which potassium persulfate (PPS) was used as the initiator and polyethyleneglycol diacrylate as the crosslinker. It was found that microwave irradiation could substantially accelerate the synthesis, without the need to remove O2 or inhibitor. Catalyzed by p-toluene sulfonic acid, polyethyleneglycol was esterified with acrylate to synthesize the crosslinker. An orthogonal test of L9(34) was designed to study the effects of relevant factors on absorbency and yield of products, including microwave power, irradiation time, initiator amount, and crosslinker content. Microwave power was believed to be the most significant factor affecting the swelling ratio and solubility of the product. Optimized experimental results showed that 10 min of microwave irradiation at 85–90 W could produce a cornstarch-based superabsorbent with a swelling ratio of 520–620 g/g in distilled water and solubility of 8.5–9.5 wt %. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 95: 264–269, 2005