Effect of Poly(aspartic acid) on the Removal Rates of Brushite Deposits from Stainless Steel Tubing in Turbulent Flow

Littlejohn, Felicia; Grant, Christine S.; Wong, Yu Ling; Sáez, A. Eduardo

doi:10.1021/ie0201011

Cited by 9 publications

(11 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The following additives were tested: Tween 20, polysorbate surfactant; TAC, ammonium citrate tribasic; EDTA, ethylenediaminetetraacetic acid (all provided by CTS S.r.l); PASP, sodium polyaspartate (Lanxess). All these additives are commonly used for these purposes except for PASP, which was selected as a possible "green" alternative to EDTA [35]. Agar gels with different concentrations and additives were tested with different application times: 15, 30, 60, 120 minutes.…”

Section: Methodsmentioning

confidence: 99%

Setup of a sustainable indoor cleaning methodology for the sculpted stone surfaces of the Duomo of Milan

et al. 2014

View full text Add to dashboard Cite

Cleaning is a fundamental phase of the conservation and maintenance activity of the cultural heritage. It is required to be highly effective in the removal of undesired deposits, controllable at every stage and gradable, selective, and completely respectful of the substrate. Moreover, cleaning procedures which can also assure to be harmless to the environment and the operators are particularly valued nowadays. According to these general guidelines, in the present work a sustainable approach for the cleaning of indoor surfaces of the cultural heritage is presented. A methodology based on agar gel was setup and preliminary tested on pilot areas. It has been then applied to the stone sculpted surfaces of the "Fuga in Egitto" high-relief of the Duomo of Milan. A multi-analytical approach was carried out during the setup phase to compare the efficacy of different cleaning conditions in terms of agar concentration, application time and presence of additives. Hence, spectrophotometric measurements, optical observations, ESEM-EDX analyses, Fourier Transform Infrared Spectroscopy, and X-Ray Diffraction were performed. Specific attention was paid to the aesthetic features of the sculpted surfaces before and after the cleaning. For this purpose, spectrophotometric data have been analysed by multivariate analysis techniques such as Principal Component Analysis and Hierarchic Cluster Analysis. The overall intervention has been monitored to evaluate the cleaning results and to confirm the absence of any damage to the stone substrate. The application of agar gel proved to be effective in removing soluble salts and soot particles, as well as very respectful of the valuable sculpted surfaces. This methodology is also totally safe for both the operators and the visitors, it is based on a natural and low-cost raw material, and it is low time-consuming. It can be therefore considered as a sustainable alternative to the traditional procedures.

show abstract

Section: Methodsmentioning

confidence: 99%

Setup of a sustainable indoor cleaning methodology for the sculpted stone surfaces of the Duomo of Milan

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Investigators have tried to nd out effective and environmentally safe chelating agents to provide a feasible alternative to acid dissolution, which can cause corrosion in metallic process equipment and piping systems. 47 Previous studies demonstrate that PASP can promote the dissolution of calcium oxalate and calcium phosphate due to its ability to chelate metal ions in solution. [47][48][49] Therefore, the chelation of PASP with magnesium may also be a driving force for struvite dissolution.…”

Section: Effect Of Pasp Concentration On Struvite Dissolutionmentioning

confidence: 99%

“…47 Previous studies demonstrate that PASP can promote the dissolution of calcium oxalate and calcium phosphate due to its ability to chelate metal ions in solution. [47][48][49] Therefore, the chelation of PASP with magnesium may also be a driving force for struvite dissolution. Herein, the dependence of struvite dissolution on PASP concentration was examined at pH 8.…”

Section: Effect Of Pasp Concentration On Struvite Dissolutionmentioning

confidence: 99%

Chemical control of struvite scale by a green inhibitor polyaspartic acid

Yao

et al. 2015

RSC Adv.

View full text Add to dashboard Cite

show abstract

“…PASP is an effective calcium chelant and has been shown both to inhibit crystallization of calcium salts and to promote dissolution of calcium minerals under various conditions. − A study done by our group investigated the effect of PASP on the dissolution of the calcium phosphate minerals DCPD (brushite) and HAP (hydroxyapatite)/DCPD under turbulent flow conditions. Dissolution was enhanced at alkaline pHs over a wide range of PASP concentrations and at low pHs from moderate to high PASP concentrations . It was concluded that PASP accelerates the rate of calcium phosphate removal via calcium sequestration during the interfacial dissolution step.…”

Section: Introductionmentioning

confidence: 95%

“…In recent years, a nontoxic, environmentally benign polymer, polyaspartic acid (PASP), has been identified as a possible “green” alternative to traditional calcium cleaning agents. ,− Donlar Corporation was awarded the 1996 Presidential Green Chemistry Challenge Award for developing environmentally safe thermal polyaspartate for use as a scale inhibitor for calcium carbonate, calcium sulfate, and barium sulfate . In a variety of tests, commercial polyaspartates of 3000−30 000 molecular weight met criteria for ready biodegradability, the most stringent measure of biodegradability .…”

Section: Introductionmentioning

confidence: 99%

Mechanisms of Calcite Dissolution Using Environmentally Benign Polyaspartic Acid: A Rotating Disk Study

Burns

Grant

2003

Langmuir

Self Cite

View full text Add to dashboard Cite

The removal of calcium mineral deposits from metal surfaces is of practical interest for a variety of fields (i.e., food, petroleum, and chemical industries). This study investigated the mechanisms of calcite (CaCO3) dissolution using environmentally benign polyaspartic acid (PASP) under controlled hydrodynamic conditions by a rotating disk technique. The specific role of PASP conformation and surface interactions in the dissolution process was further studied using scanning electron microscopy and dynamic light scattering techniques. Using this combined approach, the dissolution mechanisms were investigated as a function of pH (3.5-10.0), rotating speed (150-1500 rpm), polymer concentration (0.001-0.1 M), and molecular weight (3000 and 10 000 M w). To quantify the effect of PASP on enhancing calcite dissolution, an enhancement factor, ηenh, was defined as a ratio of the rate of dissolution in PASP over the rate in water. Maximum enhancement was observed at pHs in the range 4-5, where an optimal combination of acid attack and chelant attack may appear. Dissolution is governed primarily by interfacial phenomena, including adsorption and surface reactions, at high pHs (>7), while it is controlled by mass transport at low pHs (<7). Increasing polymer concentration under acidic pH conditions, or increasing pH, raises the contribution of the interfacial controlled dissolution mechanism. Dissolution at high pHs is inhibited by small amounts of PASP (0.001-0.01 M) and enhanced by large quantities (0.1 M) of PASP, and proceeds via a surface complexation mechanism involving the chelation of calcium by PASP. A kinetic model incorporating surface adsorption and sequestration chemistry was developed to successfully calculate the dissolution kinetics of calcite at pHs above 7. In contrast, dissolution at low pHs occurs predominantly by acid attack from all acidic species (including H + and all partly dissociated PASP species), and PASP enhances dissolution over the entire concentration range (0.001-0.1 M). The lower molecular weight (3000) PASP is the more efficient dissolving agent at low pHs than the higher molecular weight (10 000) PASP. Dissolution at low pHs represents the most complicated case. An analysis of the dissolution mechanisms at low pHs was conducted on the basis of the consideration of mass transfer, polymer surface adsorption, conformation of polymers, and surface interactions.

show abstract

Effect of Poly(aspartic acid) on the Removal Rates of Brushite Deposits from Stainless Steel Tubing in Turbulent Flow

Cited by 9 publications

References 15 publications

Setup of a sustainable indoor cleaning methodology for the sculpted stone surfaces of the Duomo of Milan

Setup of a sustainable indoor cleaning methodology for the sculpted stone surfaces of the Duomo of Milan

Chemical control of struvite scale by a green inhibitor polyaspartic acid

Mechanisms of Calcite Dissolution Using Environmentally Benign Polyaspartic Acid: A Rotating Disk Study

Contact Info

Product

Resources

About