Polymaleic Acid Research Articles

Adsorption of (poly)maleic acid and an aquatic fulvic acid by geothite

The adsorption of Suwannee River fulvic acid (SRFA) and a synthetic organic polymer, polymaleic acid (PMA) by geothite was studied. The adsorption density of the sorbates decreased with increasing pH, and the data could best be described by the Langmuir adsorption equation. The number- and weight-averaged molecular weights, Mw and Mn, of the sorbates in the solution phase before and after adsorption by geothite were measured by high-pressure size exclusion chromatography. The observed decreases in the M n and Mw of SRFA in the solution phase after adsorption demonstrated that fractionation of SRFA on the basis of molecular size occured. UV molar absorptivities measured at 280 nm also decreased, which suggests that the more aromatic moieties are preferentially adsorbed. Potentiometric titrations conducted on SRFA revealed changes in the conditional acidity constants (expressed as the negative logarithm, pK a) of the fulvic acid after adsorption. The increased pK a value of the humic material remaining in the solution after adsorption implies that the strongly sorbing compounds possessed stronger acidic functional groups. Fractionation of PMA after adsorption, however, did not occur to the same extent compared to SRFA because PMA is relatively homogeneous. The experimental results confirm that molecular weight, aromaticity, and organic acidity are major factors controlling the fractionation of natural organic matter (NOM) by adsorption onto hydrous mineral oxides. PMA, a relatively uniform and less polydisperse organic polymer, may serve as an endmember material characteristic of NOM that exhibits the least amount of fractionation upon adsorption.

A Study on Inorganic Nanoparticles/Amphiphilic Oligomer in Nanoordered Multilayer

An amphiphilic oligomer, polymaleic acid with octadecanol monoester (PMAO), and its cadmium, lead and copper salts Langmuir-Blodgett (LB) films were prepared. These films possess an ordered structure as determined by X-ray diffraction measurements and FTIR spectroscopy. The long spacing of the films is 5.7 nm. After reaction with H2S, the long spacing increased to 5.8 nm, but an ordered structure was still kept. The nanoparticulate PbS, CdS and CuS multilayers were obtained. From the UV-vis spectrum, it was found that the nanoparticles within PMAO LB films show a larger blue shift of the optical absorption edge than that formed within the stearic acid LB film.

Barium Sulfate Precipitation: Crystallization kinetics and the role of the additive PMA‐PVS

AbstractThe precipitation of barium sulfate was investigated by photon correlation spectroscopic (PCS) measurements of the growing crystals combined with electrical conductivity measurements of the mother solution. Small silica seeds (36nm) were added to the solution. Therefore, heterogeneous nucleation did not take place on the walls and on the stirrer, which is usually the case, but on the seeds. Hence the growth of the crystals which had nucleated on the seeds could be studied by PCS. In order to avoid the ill‐conditioned inversion of the measured raw data, the autocorrelation functions, a population balance model was used to calculate these functions with the help of a kinetic model taken from the literature. The measured an the calculated autocorrelation functions could coincide and adjustable parameters were found from a least‐squares fit. The measurements revealed that nucleation is strongly enhanced by PMA‐PVS (polymaleic acid–polyvinylsulfonic acid). However, a simple model which assumes langmuir adsorption of PMA‐PVS on the crystal surface did not describe the kinetics very well. The nucleation rate in the absence of the additive was found to be J=1.3·1010 exp(−27/In2S) [m−3s−1], while the growth rate was G=2.6·10−8(S−1)2/3 S1/3 exp(−29/3 In S) [ms−1]. These results match results taken from the literature fairly well.

Adsorption of Organic Macromolecules by Granular Activated Carbon. 2. Influence of Dissolved Oxygen

The influence of dissolved oxygen (DO) on the uptake of natural and synthetic macromolecular dissolved organic materials (DOMs) from aqueous solutions by granular activated carbon (GAC) was investigated. The sorption behaviors of six of the nine DOMs tested were enhanced by the presence of DO; these included polymaleic acid, peat humic acid, Leonardite humic acid, Suwannee River fulvic acid, and Laurentian fulvic and humic acids. The sorptions of Aldrich and soil humic acids and polystyrene sulfonate were not sensitive to the presence or absence of DO. Sensitivity of sorption to DO generally increased with decreasing molecular size, polydispersity, and aromaticity and with increasing acidity for the five natural DOMs. Oxygen-sensitive sorption of the low molecular weight fractions of peat humic acid, a slightly oxygen-sensitive DOM, was noticeably greater than that of the whole material. Sorption of the low molecular weight fractions of Aldrich humic acid, an oxygen-insensitive DOM, did not show any particular sensitivity to oxygen.

Adsorption of Natural Organic Polyelectrolytes by Activated Carbon: A Size-Exclusion Chromatography Study

The adsorption of several different organic polyelectrolytes from aqueous solution by activated carbon was characterized. Polyelectrolytes included humic acids extracted from peat and soil, polymaleic acid, a synthetic polymer identified as a fulvic acid surrogate, and natural organic matter in Huron River (Ann Arbor, MI) water. Isotherms of individual ultrafiltration size fractions confirmed that smaller molecular size components adsorb to a greater extent on an adsorbent mass basis. The molecular weight distributions of organic polyelectrolytes remaining in solution after equilibration with various amounts of activated carbon were measured with high-performance size-exclusion chromatography (HPSEC). A comparison of molecular weight distributions demonstrated conclusively that small molecular size components are adsorbed preferentially; i.e., adsorptive fractionation on the basis of molecular size occurs. This behavior was observed for each of the wide variety of samples studied, suggesting that it may b...

Physical and chemical characteristics of poly(maleic acid), a synthetic organic colloid analog

Abstract A relatively homogenous and easily synthesized polymer, polymaleic acid (PMA), was studied to ascertain its suitability as a model compound for humic substances. Physical and chemical properties of PMA were measured by UV/VIS, Fourier-transform infrared, and 13C NMR spectroscopy, high pressure size exclusion chromatography, and elemental analyses to elucidate the structural characteristics of PMA and aquatic humic substances. In terms of size, polydispersity, elemental composition, and infrared spectra, PMA most closely resembles fulvic acids derived primarily from terrestrial sources. Molar absorptivity (measured at 280 nm) and 13C NMR spectroscopic data, however, show that PMA exhibits significantly less aromaticity than fulvic materials of similar size. In general, terrestrially derived aquatic fulvic acids possess larger percentages of aromatic carbons than either PMA or the lacustrine and subsurface fulvic acids. 13C NMR spectra also show that aliphatic II and acetal carbons, present in several aquatic fulvic acids, are absent in PMA. Furthermore, the carboxyl carbon content of PMA is significantly higher than that of all the humic materials used in this study. Based on these results, PMA does not resemble a unique humic substance, but rather appears to possess chemical properties common to humic materials from diverse sources.

Using different types of anti-scalants at the Al-Jubail power and desalination plant in Saudi Arabia

The purpose of this paper is to review the results of using different types of anti-scalant chemicals at the Al-Jubail Desalination Plant. A major problem in the desalination of sea-water is the scaling that takes place. During the desalination process brine flows inside heat transfer tubes causing a rapid growth of scale within the tubes which eventually results in a deterioration of plant performance. The desalination plant at Al-Jubail is considered to be the largest of its kind in the world and is capable of producing 240 migd at a low top brine temperature of 90°C and 281.6 migd at a high TBT of 112.8°C. Experience has shown that there are only two practical methods to prevent scale in a MSF plant, namely treatment of the scale by acid or by the use of chemical additives. The evaporators used at the plant were designed to use additive scale control method. Treatment of scale with an acid has not yet been used at the plant to clean the evaporators or Condensers. Two different types of anti-scalant treatments are used at the plant which are classified into three anti-scalant groups namely; poly-maleic acid, poly-phosphate and poly-phosphonate. This paper will compare the results experienced using the above chemicals. This paper will also discuss the necessity of anti-scalant selection for every operating mode in MSF evaporators. Factors will be reviewed to assess and evaluate the quality and performance the anti-scalant. Specifications of all the above chemicals is provided to assist in the selection of anti-scalants by other users without the need for expensive tests and trials.

Impacts of dissolved oxygen on the sorption of humic substances and the subsequent inhibition of o-cresol ptake by granular activated carbon

The impacts of dissolved oxygen (DO) on the sorption of natural and model humic substances by granular activated carbon (GAC) were investigated. Among five substances tested, the sorptions of only two, polymaleic acid (PMA) and peat humic acid, were affected by the presence of DO. The uptake of the target compound o-cresol on virgin GAC and on GAC preloaded with PMA under oxic and anoxic conditions was also examined. The oxic and anoxic preloading conditions had similar effects on subsequent o-cresol reactions under both oxic and anoxic sorption conditions. A reduction of approximately 20 % in o-cresol uptake observed under anoxic conditions by GAC preloaded under each condition is attributed to a decrease in the adsorption capacity of the GAC by preloading. In the presence of oxygen, however, an observed reduction of about 45% in o-cresol uptake by preloaded GAC appears to result from a combination of decreased adsorption and inhibited o-cresol polymerization.

Build-up of polymeric molecular deposition films bearing mesogenic groups

A multilayer film was deposited by molecular deposition onto aminopropylsilanated silicon or quartz through the alternate salt-forming reaction of a monester of polymaleic acid containing an azobenzene-sulphonic salt side chain and a bipolar quaternary ammonium bearing biphenyl mesogenic group. UV-visible and polarized UV-visible spectra were employed to study the growing process and the aggregation of chromophore. A well-ordered superlattice structure was identified by X-ray diffraction.

Interaction of pesticides with the soluble fraction of natural and artificial humic substances

Abstract The adsorption of two cationic pesticides on the soluble part of natural and artificial humic substances, and their mechanisms of interaction, have been studied using the equilibrium dialysis method. Paraquat and chlordimeform in diverse concentrations have been used. A natural fulvic acid extracted from a spodosol soil, a commercial humic acid and polymaleic acid vere used as comparison. Chlordimeform adsorption data from this work are higher than those obtained in a previous paper without dissolving the humic substances. Paraquat isotherms always present values lower than chlordimeform ones. Natural fulvic acid adsorbs more than the commercial humic substance for both pesticides. The results show that acidified soluble fraction of the commercial HA is more similar to natural FA than polymaleic acid. However the latter is generally used as a model for fulvic acid. The interaction mechanisms between these humic substances and cationic pesticides were principally cation‐exchange processes, but H‐b...

Structural investigations of humic substances by IR-FT, 13C-NMR spectroscopy and comparison with a maleic oligomer of known structure

Humic and fulvic acids isolated from an Italian Typic Dystrochrept by conventional means have been investigated by spectroscopic techniques (IR-FT, 13C-NMR). A quantitative 13C-NMR technique was applied. The investigated fulvic acid contains more aliphatic than aromatic moieties. The carboxyl contents of fulvic acid are greater than those of humic acid. In comparison with fulvic acid the humic acid has a higher content of aromatics. The data presented indicate that structural units resembling those of polymaleic acid may be present in fulvic acid but similar structures have not been detected in humic acid.

Structural study on the polar Langmuir-Blodgett films of a new azo-containing polymer through polarized infrared and UV-visible spectroscopy

A new amphiphilic polymer (monoesters of polymaleic acid containing anthraquinone-azo-naphthalene groups) was designed for Z-type Langmuir-Blodgett deposition. Its monolayer on water was described by means of an intensive discussion of the pressure-area isotherm. Its multilayer conformation on substrates was studied through UV-visible and infrared linear dichroism measurements. Conclusions derived from the π- A isotherm and polarized spectra were demonstrated to be consistent. The multilayer was found to exhibit three-dimensional anisotropy: the two aromatic rings standing up and orienting preferentially with their planes perpendicular to the transfer direction; the azo linkage and hydrocarbon chain normal to the film plane.

Corrosion Inhibition of Mild Steel by Cationic and Anionic Polymers in Cooling Water System

The behavior of corrosion inhibition of mild steel by various cationic and anionic polymers, that is, polyethyleneimine (PEI), its derivative (PEID), polyarylamine (PAAm) and polydicyanodiamide derivative (PDCDA) as cationic polymers and polymaleic acid derivative (PMAD), polyacrylic acid derivative (PAAD) and polyacrylic acid (PAA) as anionic polymers, was investigated by corrosion tests and physicochemical measurements. Testing was done in two pseudoconcentrated solutions with low (LC) and high (HC) concentrations of ionic species like Ca2+ and Cl−. The cationic polymers lacked inhibition ability, while the anionic polymers had a more effective inhibition ability. The anionic polymers had a potential to act as corrosion inhibitors of an adsorption‐type in LC solution and as both corrosion inhibitors and scale inhibitors of calcium carbonate . In LC solution, the inhibition efficiency (η) value of anionic polymers was dependent on number‐average molecular weight , content of carboxylic group (‒COOH), and concentration of ‒COOH. In particular, the anionic polymers as inhibitors had an effective range of (103 order). In HC solution, the degree of corrosion of steel was influenced by concentrations of both anionic polymers and solution components such as Ca ion ; the anionic polymers were competitively adsorbed with Ca ion on the steel.

Synthesis of monoesters of polymaleic acid and characterization of their Langmuir-Blodgett films

Several amphiphilic polymers, monoesters of polymaleic acid containing anthraquinone-azo-side groups (PMAME-AQ) were synthesized for LB film fabrication. Both Z-type and Y-type films were successfully deposited and the film structure and properties were characterized by means of UV-visible linear dichroism and infrared linear dichroism.

Influence of natural and synthetic humic substances on the activity of urease

SUMMARYThe activity of a purified urease, obtained from Bacillus pasteurii, was inhibited by humic and fulvic acids obtained from an agricultural soil. Enzyme kinetic studies showed that the humic substances affected the affinity of the enzyme for its substrate (Km) and the maximum velocity of the reaction (Vmax). The Vmax was inhibited to the same extent by both humic (HA) and fulvic (FA) acids, the precise effect depending on the pH and concentration of humic substance. At pH 4.0, HA concentrations of 25 pg cm−3 and 10 μg cm−3 inhibited the Vmax by 38.5% and 20% respectively. HA and FA had similar effects on the Km but in this case the lowering of the affinity of the enzyme for its substrate was not concentration dependent in the range 0–25 μg cm−3 of humic substance. Typically, the affinity was decreased from a KM of 50 mM in the control to 67 mM in the presence of HA and FA.The effects were not due primarily to the ash or N contents of the humic substances because de‐ashed humic acid and synthetic model humic (made from catechol, guaiacol, pyrogallol, resorcinol and protocatechuic acid) and fulvic acid (made from polymaleic acid), containing virtually no ash or N, were equally as effective. The effect was not related to the phenolic monomers which, before polymerization, had no effect on urease activity.

Kinetics of dissociation of thorium(IV) bound to polymaleic acid and poly(methylvinylether) maleic acid

The kinetics of dissociation of Th(IV) from its complexes with polymaleic acid (PMA) and poly(methyl vinyl ether) maleic acid (PMVEMA) were found to follow rate expressions that reflected seven separate terms ranging in lifetimes between 0.1 s and almost 1 h. The fraction of thorium dissociating by any one of the seven paths depended on the length of time during the first 2 days that the thorium had been bound to the polyelectrolyte prior to dissociation. After 48 h of binding, no further change was observed in the dissociation kinetics. These observations are interpreted in terms of the present models of metal-polyelectrolyte interaction. 10 refs., 2 figs., 4 tabs.

Further studies on homopolymers and copolymers resulting from the reaction of polymaleic anhydride with alcohols and amines

AbstractPolymaleic anhydride prepared by γ‐rays irradiation of maleic anhydride was used as a reactive polymer and reacted with certain long‐chain aliphatic amines and/or alcohols as well as with the mesogenic biphenylamine. The homopolymers and copolymers that were prepared, i.e., derivatives of N‐alkyl polymaleamic acid, monoesters of polymaleic acid, or mixed amide‐ester derivatives, were primarily investigated as far as their property to show thermotropic liquid crystalline character is concerned. By this investigation the structural features for the exhibition of mesomorphism by these polymers were determined.

Effect of carboxylic acids on the dissolution of calcite in aqueous solution. Part 3.—Polymaleic acid

The kinetics of calcite dissolution in polymaleic acid (PMA) solution (pH 2.70) have been determined using channel-electrode shielding measurements. Initially, the dissolution reaction proceeded with a rate constant (k′0= 0.02–0.04 cm s–1) similar in magnitude to that for the H+/calcite reaction in the absence of PMA. However, the reaction rate slowly decreased with time. This was attributed to the reversible adsorption of PMA at reactive sites on the calcite surface and a kinetic model for the adsorption–desorption processes was developed, for which the corresponding rate constants were deduced. The steady-state dissolution rate constant (k′) was found to depend on the concentration of PMA according to the following equation (k′)–1=(k′0)–1+ 1.4 × 108 cm2 s mol–1[PMA].The likely adsorption sites for the polymer were inferred from interference light microscopy studies of the dissolution etch-pit morphologies.

Inhibitor effects on calcite growth at low supersaturations

The effect of the inhibitors sodium triphosphate (STP) and poly(maleic) acid (PMA) on the crystal growth kinetics of calcite has been studied in the supersaturation range 0.6 < σ < 2.5 using the constant composition technique. In the absence of inhibitor, constant growth rates to high outgrowths are observed.

Mesomorphic-like character of long-chain amine salts formed by template neutralization on polyacids

Abstract Several examples of monomeric and polymerized surfactants exhibiting liquid-crystalline behaviour have recently been reported. In the present investigation a novel process for the formation of liquid crystals is introduced, according to which certain functionalized polymers induce mesomorphism when they react with appropriate amines. For instance, neutralization of polyacrylic or polymaleic acid with long-chain amines forms alkylammonium salt surfactants which exhibit mesomorphic-like character. In this type of experiment, however, the known lamellar structure of alkylammonium salts was modified by this so-called template neutralization. The carboxylate groups, due to their location on the polymeric chain, appear to exert a topochemical effect on alkylammonium moieties which in turn affect the mesomorphic behaviour compared with that of common surfactants. The mesomorphic behaviour of these materials was established by optical microscopy and differential scanning calorimetry.