Qingzhao Yao

Acrylic Acid-Allylpolyethoxy Carboxylate Copolymer Dispersant for Calcium Carbonate and Iron(III) Hydroxide Scales in Cooling Water Systems

Abstract A novel environmentally friendly type of calcium carbonate and iron(III) scale inhibitor (ALn) was synthesized. The anti-scale property of the Acrylic acid-allylpolyethoxy carboxylate copolymer (AA-APELn or ALn) towards CaCO3 and iron(III) in the artificial cooling water was studied through static scale inhibition tests. The observation shows that both calcium carbonate and iron(III) inhibition increase with increasing the degree of polymerization of ALn from 5 to 15, and the dosage of ALn plays an important role on calcium carbonate and iron(III)-inhibition. The effect on formation of CaCO3 was investigated with a combination of scanning electronic microscopy (SEM), Transmission electron microscopy (TEM), X-ray powder diffraction (XRD) analysis and Fourier transform infrared spectrometer, respectively. The results showed that the ALn copolymer not only influences calcium carbonate crystal morphology and crystal size but also the crystallinity. The crystallization of CaCO3 in the absence of inhibitor was rhombohedral calcite crystal, whereas a mixture of calcite with vaterite crystals was found in the presence of the ALn copolymer. Inhibition mechanism is proposed that the interactions between calcium or iron ions and polyethylene glycol (PEG) are the fundamental impetus to restrain the formation of the scale in cooling water systems.

Carboxylate-Terminated Double-Hydrophilic Block Copolymer as an Effective and Environmentally Friendly Inhibitor for Carbonate and Sulfate Scales in Cooling Water Systems

Formation of mineral scales of carbonate and sulfate poses significant problems in cooling water systems. For the control of carbonate and sulfate scales and in response to environmental guidelines, a novel phosphorus-free and non-nitrogen double-hydrophilic block copolymer (AL) was synthesized. The anti-scale property of the AL copolymer towards CaCO3 and CaSO4 in the artificial cooling water was studied through static scale inhibition tests. The observation shows that the dosage of AL plays an important role on CaCO3 and CaSO4 inhibition. The effect on formation of CaCO3 and CaSO4 was investigated with combination of scanning electronic microscopy, transmission electron microscopy, and X-ray powder diffraction analysis, respectively. Inhibition mechanism is proposed that the interactions between calcium and polyethylene glycol are the fundamental impetus to restrain the formation of the scale in cooling water systems.

Preparation and application of a phosphorous free and non-nitrogen scale inhibitor in industrial cooling water systems

A novel environmentally friendly type of calcium carbonate, zinc (II) and iron (III) scale inhibitor Acrylic acidallylpolyethoxy carboxylate copolymer (AAAPEL) was synthesized. The anti-scale property of the AA-APEL toward CaCO3, zinc (II) and iron (III) in the artificial cooling water was studied through static scale inhibition tests. The observation shows that both calcium carbonate, zinc (II) and iron (III) inhibition increase with increasing the dosage of AA-APEL. The effect on formation of CaCO3 was investigated with combination of scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD) analysis and fourier transform infrared spectrometer, respectively. The results showed that the AA-APEL copolymer not only influenced calcium carbonate crystal morphology and crystal size but also the crystallinity. The crystallization of CaCO3 in the absence of inhibitor was rhombohedral calcite crystal, whereas a mixture of calcite with vaterite crystals was found in the presence of the AAAPEL copolymer. Inhibition mechanism is proposed that the interactions between calcium or iron ions and polyethylene glycol (PEG) are the fundamental impetus to restrain the formation of the scale in cooling water systems.

Carboxylate-Terminated Double-Hydrophilic Block Copolymer Containing Fluorescent Groups: An Effective and Environmentally Friendly Inhibitor for Calcium Carbonate Scales

Allyloxy polyethoxy ether (APEG) and succinic anhydride were used to prepare allyloxy polyethoxy carboxylate (APEL). 8-hydroxy-1,3,6-pyrene trisulfonic acid trisodium salt (PY) was reacted with allyl chloride to produce fluorescent monomer 8-allyloxy-1,3,6-pyrene trisulfonic acid trisodium salt (PA). APEL and PA were copolymerized with acrylic acid (AA) to synthesize PA tagged no phosphate and nitrogen free CaCO3 inhibitor AA-APEL-PA. Structures of PA, APEG, APEL, and AA-APEL-PA were carried out by FT-IR and 1H-NMR. The observation shows that the dosage of AA-APEL-PA plays an important role on CaCO3 inhibition. The effect on formation of CaCO3 was investigated with combination of scanning electronic microscopy and X-ray powder diffraction analysis. Relationship between AA-APEL-PAs fluorescent intensity and its dosage was studied. Correlation coefficient r of AA-APEL-PAs fluorescent intensity and its dosage is 0.9998. AA-APEL-PA can be used to accurately measure polymer consumption on line besides providing excellent CaCO3 inhibition.

Performance of an environmentally friendly anti-scalant in CaSO4 scale inhibition

AbstractThe precipitation of calcium sulfate (CaSO4) scale on heat transfer surfaces widely occurs in numerous industrial processes. For the control of calcium sulfate scale, a novel environmentally friendly type of scale inhibitor Acrylic acid–oxalic acid–allypolyethoxy carboxylate (AA-APEM9) was synthesized and characterized, and the anti-scale property of the AA-APEM9 copolymer towards calcium sulfate in the artificial cooling water was studied through static scale inhibition tests. It was shown that AA-APEM9 exhibited excellent ability to control calcium sulfate scale, with approximately 97.1% calcium sulfate inhibition at a level of 4 mg/L AA-APEM9. Scanning electron microscopy and X-ray powder diffraction studies have been performed to identify the change in crystal surfaces by the addition of the copolymer. Inhibition mechanism is proposed that PAA can recognize and react with positively charged calcium ions on the surface of inorganic minerals and water-compatible PEG segments increase its solubil...

Acrylic acid–allylpolyethoxy carboxylate copolymer as an environmentally friendly calcium carbonate and iron(III) scale inhibitor

A novel environmentally friendly type of calcium carbonate and iron(III) scale inhibitor AQn was synthesized. The anti-scale property of the AQn copolymer toward CaCO3 and iron(III) in the artificial cooling water was studied through static scale inhibition tests. The observation shows that both calcium carbonate and iron(III) inhibition increase with increasing the degree of polymerization of AQn from 5 to 15, and the dosage of AQn plays an important role on calcium carbonate and iron(III) inhibition. The effect on formation of CaCO3 was investigated with combination of scanning electronic microscopy, transmission electron microscopy, X-ray powder diffraction analysis, and Fourier-transform infrared spectrometer, respectively. Inhibition mechanism is proposed that the interactions between calcium or iron ions and polyethylene glycol are the fundamental impetus to restrain the formation of the scale in cooling water systems.

Evaluation of a low-phosphorus terpolymer as calcium scales inhibitor in cooling water

AbstractScale formation, e.g. precipitation of calcium carbonate and calcium sulfate, is a significant problem in cooling water system. For the control of calcium scale and in response to environmental guidelines, the novel low-phosphorus terpolymer was prepared through free radical polymerization reaction of acrylic acid (AA), oxalic acid-allypolyethoxy carboxylate (APEM), and phosphorous acid (H3PO3) in water with redox system of hypophosphorous and ammonium persulfate as initiator. The synthesized AA–APEM–H3PO3 terpolymer was characterized by Fourier transform infrared spectrometer (FT-IR) and 1H NMR. The inhibition property of the low-phosphorus terpolymer towards CaCO3 and CaSO4 in the artificial cooling water was studied through static scale inhibition tests, and the effect on morphology of CaCO3 and CaSO4 was investigated with combination of scanning electron microscopy and X-ray powder diffraction analysis, respectively. FT-IR was also used to study the effect on morphology of CaCO3. It was shown ...

Investigation of calcium carbonate precipitation in the presence of fluorescent-tagged scale inhibitor for cooling water systems

Abstract The aim of this work is to study the effect of a water-soluble copolymer, Acrylic acid–Oxalic acid–Allypolyethoxy carboxylate–8-hydroxy-1,3,6-pyrene trisulfonic acid trisodium salt (pyranine) (AA-APEM-APTA), APEM, and APTA were copolymerized with acrylic acid (AA) to synthesize APTA-tagged no phosphate and nitrogen-free CaCO3 inhibitor, AA-APEM-APTA. Structures of APTA, APEM, and AA-APEM-APTA were carried out by FT–IR. The observation shows that the dosage of AA-APEM-APTA plays an important role on CaCO3 inhibition. It can be concluded that the order of preventing the precipitation from flask tests was AA-APEM > AA-APEM-APTA > HPMA > PAA≈PESA. Relationship between AA-APEM-APTA’s fluorescent intensity and its dosage was studied. Correlation coefficient r of AA-APEM-APTA’s is 0.99672. The effect on the formation of CaCO3 was investigated with combination of scanning electronic microscopy, transmission electron microscope, and X-ray powder diffraction analysis. AA-APEM-APTA can be used to accurately...

Study on Calcium Scales Inhibition Performance in the Presence of Double-Hydrophilic Copolymer

Novel double-hydrophilic block copolymers, acrylic acid (AA)-2-acrylamido-2-methyl-propane sulfonate (AMPS)-oxalic acid-allypolyethoxy carboxylate (APEM) was specially designed and synthesized from allyloxy polyethoxy ether (APEG) to inhibit the precipitation of CaCO3 and CaSO4. The structure of the copolymer was characterized by FT-IR and H1-NMR. Using the static experiment method, the scale inhibition efficiencies for CaCO3 and CaSO4 scale were investigated. It was shown that AA-AMPS-APEM exhibited excellent ability to control inorganic minerals scales, with approximately 97.1% CaSO4 inhibition and displayed significant ability to prevent the formation of CaCO3 scales. The synthesized AA-AMPS-APEM was also compared with that of current commercial inhibitors. The effect of the copolymer addition on the crystals of CaCO3 and CaSO4 scales morphology and structures were examined through scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray diffraction studies (XRD). It proved that great changes in the size and morphology of the calcium scales took place under the influence of AA-AMPS-APEM. The proposed inhibition mechanism suggests the formation of complexes between the side-chain carboxyl groups of AA-AMPS-APEM and calcium ions on the surface of inorganic minerals, and the excellent solubility of complexes resulted from a number of hydrophilic polyethylene glycol (PEG) and sulfonic group (-SO3H) group. GRAPHICAL ABSTRACT

Fluorescent-tagged acrylic acid-allylpolyethoxy carboxylate copolymer as a green inhibitor for calcium phosphate in industrial cooling systems

Allyloxy polyethoxy ether (APEG) and succinic anhydride were used to prepare allyloxy polyethoxy carboxylate (APEL). The 8-hydroxy-1,3,6-pyrene trisulfonic acid trisodium salt (PY) was reacted with allyl chloride to produce fluorescent monomer 8-allyloxy-1,3,6-pyrene trisulfonic acid trisodium salt (PA). APEL and PA were copolymerized with acrylic acid (AA) to synthesize PA-tagged no phosphate and nitrogen free calcium phosphate inhibitor AA–APEL–PA. Structures of PA, APEG, APEL, and AA–APEL–PA were carried out by FT-IR and 1H NMR. Different AA:APEL mole ratios were employed for the manufacture of AA–APEL–PA to study the effect of mole ratio on performance of AA–APEL–PA. Relationship between AA–APEL–PA’s fluorescent intensity and its dosage was studied. The results indicate that capability of AA–APEL–PA is heavily depended on the mole ratio of AA:APEL. Correlation coefficient r of AA–APEL–PA’s fluorescent intensity and its dosage is 0.9995, and detection limit of AA–APEL–PA is 0.98 mg/L. AA–APEL–PA can be used to accurately measure polymer consumption on line besides providing excellent calcium phosphate inhibition.