### Abstract

The effect of calcium on the stability of a commercial MWF is characterized through the experimental determination of the stability ratio, W. Three experimental methods of stability ratio evaluation are investigated. (1) The initial slope of the absorbance versus time curve is used to estimate the rate of coagulation. (2) Absorbance measurements are used to estimate N0/N with time. The stability ratio is determined from the slope of N0/N versus time. (3) Photon correlation spectroscopy (PCS) measurements of the volume distribution with time are used to estimate N0/N with time. Electrophoretic mobility was also measured and used to determine the fast coagulation concentration of the MWF. The accuracy of the experimentally determined stability ratios is evaluated using a population balance coagulation model. The model predicts the population distribution of a coagulating dispersion with time based on an initial particle size distribution and stability ratio. The model results were compared with the PCS-measured distributions to determine which stability ratio evaluation method best describes the stability of the MWF emulsion studied. Using the initial slope of the absorbance versus time curve to determine the fast coagulation concentration correlates well with electrophoretic mobility measurements. However, using absorbance measurements to determine the rate of coagulation underestimates the stability ratio of the MWF studied by orders of magnitude. N0/N values calculated from absorbance measurements provide a reasonable estimate of the stability ratio but inconsistencies in the method decrease its reliability. The stability ratio derived from PCS measurements appears to provide the most accurate, reliable description of MWF stability.

Language | English (US) |
---|---|

Pages | 477-488 |

Number of pages | 12 |

Journal | Journal of Colloid and Interface Science |

Volume | 284 |

Issue number | 2 |

DOIs | |

State | Published - Apr 15 2005 |

Externally published | Yes |

### Fingerprint

### Keywords

- Colloidal stability
- Metal working fluid
- Population balance model
- Stability ratio

### ASJC Scopus subject areas

- Colloid and Surface Chemistry
- Physical and Theoretical Chemistry
- Surfaces and Interfaces

### Cite this

*Journal of Colloid and Interface Science*,

*284*(2), 477-488. DOI: 10.1016/j.jcis.2004.07.027

**An evaluation of the colloidal stability of metal working fluid.** / Menniti, Adrienne; Rajagopalan, Kishore; Kramer, Timothy A.; Clark, Mark M.

Research output: Research - peer-review › Article

*Journal of Colloid and Interface Science*, vol 284, no. 2, pp. 477-488. DOI: 10.1016/j.jcis.2004.07.027

}

TY - JOUR

T1 - An evaluation of the colloidal stability of metal working fluid

AU - Menniti,Adrienne

AU - Rajagopalan,Kishore

AU - Kramer,Timothy A.

AU - Clark,Mark M.

PY - 2005/4/15

Y1 - 2005/4/15

N2 - The effect of calcium on the stability of a commercial MWF is characterized through the experimental determination of the stability ratio, W. Three experimental methods of stability ratio evaluation are investigated. (1) The initial slope of the absorbance versus time curve is used to estimate the rate of coagulation. (2) Absorbance measurements are used to estimate N0/N with time. The stability ratio is determined from the slope of N0/N versus time. (3) Photon correlation spectroscopy (PCS) measurements of the volume distribution with time are used to estimate N0/N with time. Electrophoretic mobility was also measured and used to determine the fast coagulation concentration of the MWF. The accuracy of the experimentally determined stability ratios is evaluated using a population balance coagulation model. The model predicts the population distribution of a coagulating dispersion with time based on an initial particle size distribution and stability ratio. The model results were compared with the PCS-measured distributions to determine which stability ratio evaluation method best describes the stability of the MWF emulsion studied. Using the initial slope of the absorbance versus time curve to determine the fast coagulation concentration correlates well with electrophoretic mobility measurements. However, using absorbance measurements to determine the rate of coagulation underestimates the stability ratio of the MWF studied by orders of magnitude. N0/N values calculated from absorbance measurements provide a reasonable estimate of the stability ratio but inconsistencies in the method decrease its reliability. The stability ratio derived from PCS measurements appears to provide the most accurate, reliable description of MWF stability.

AB - The effect of calcium on the stability of a commercial MWF is characterized through the experimental determination of the stability ratio, W. Three experimental methods of stability ratio evaluation are investigated. (1) The initial slope of the absorbance versus time curve is used to estimate the rate of coagulation. (2) Absorbance measurements are used to estimate N0/N with time. The stability ratio is determined from the slope of N0/N versus time. (3) Photon correlation spectroscopy (PCS) measurements of the volume distribution with time are used to estimate N0/N with time. Electrophoretic mobility was also measured and used to determine the fast coagulation concentration of the MWF. The accuracy of the experimentally determined stability ratios is evaluated using a population balance coagulation model. The model predicts the population distribution of a coagulating dispersion with time based on an initial particle size distribution and stability ratio. The model results were compared with the PCS-measured distributions to determine which stability ratio evaluation method best describes the stability of the MWF emulsion studied. Using the initial slope of the absorbance versus time curve to determine the fast coagulation concentration correlates well with electrophoretic mobility measurements. However, using absorbance measurements to determine the rate of coagulation underestimates the stability ratio of the MWF studied by orders of magnitude. N0/N values calculated from absorbance measurements provide a reasonable estimate of the stability ratio but inconsistencies in the method decrease its reliability. The stability ratio derived from PCS measurements appears to provide the most accurate, reliable description of MWF stability.

KW - Colloidal stability

KW - Metal working fluid

KW - Population balance model

KW - Stability ratio

UR - http://www.scopus.com/inward/record.url?scp=15244343191&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=15244343191&partnerID=8YFLogxK

U2 - 10.1016/j.jcis.2004.07.027

DO - 10.1016/j.jcis.2004.07.027

M3 - Article

VL - 284

SP - 477

EP - 488

JO - Journal of Colloid and Interface Science

T2 - Journal of Colloid and Interface Science

JF - Journal of Colloid and Interface Science

SN - 0021-9797

IS - 2

ER -