576:
413:
140:
84:
920:
particles with different masses or sizes lead to the separation. An exponential distribution of particles of a certain size or weight is results due to the
Brownian motion. Some of the assumptions to develop the theoretical equations include that there is no interaction between individual particles and equilibrium can occur anywhere in separation channels.
910:
Some main aspects of SFFF include: it provides high-resolution possibilities for size distribution measurements with high precision, the resolution is dependent on experimental conditions, the typical analysis time is 1 to 2 hours, and it is a non-destructive technique which offers the possibility of
919:
As sedimentation field flow fractionation (SFFF) is one of field flow fractionation separation techniques, it is appropriate for fractionation and characterization of particulate materials and soluble samples in the colloid size range. Differences in interaction between a centrifugal force field and
147:
The following relation provides a measure of the sedimentation potential due to the settling of charged spheres. First discovered by
Smoluchowski in 1903 and 1921. This relationship only holds true for non-overlapping electric double layers and for dilute suspensions. In 1954, Booth proved that this
591:
is attached to measure the potential generated from the suspension. To account for different geometries of the electrode, the column is typically rotated 180 degrees while measuring the potential. This difference in potential through rotation by 180 degrees is twice the sedimentation potential. The
118:
Smoluchowski built the first models to calculate the potential in the early 1900s. Booth created a general theory on sedimentation potential in 1954 based on
Overbeek's 1943 theory on electrophoresis. In 1980, Stigter extended Booth's model to allow for higher surface potentials. Ohshima created a
906:
Sedimentation field flow fractionation (SFFF) is a non-destructive separation technique which can be used for both separation, and collecting fractions. Some applications of SFFF include characterization of particle size of latex materials for adhesives, coatings and paints, colloidal silica for
98:
The common source of all these effects stems from the interfacial 'double layer' of charges. Particles influenced by an external force generate tangential motion of a fluid with respect to an adjacent charged surface. This force may consist of electric, pressure gradient, concentration gradient,
892:
An improved design cell was developed to determine sedimentation potential, specific conductivity, volume fraction of the solids as well as pH. Two pairs of electrodes are used in this set up, one to measure potential difference and the other for resistance. A flip switch is utilized to avoid
561:
596:
can be determined through measurement by sedimentation potential, as the concentration, conductivity of the suspension, density of the particle, and potential difference are known. By rotating the column 180 degrees, drift and geometry differences of the column can be ignored.
131:
is induced. While the particle moves, ions in the electric double layer lag behind creating a net dipole moment behind due to liquid flow. The sum of all dipoles on the particle is what causes sedimentation potential. Sedimentation potential has the opposite effect compared to
420:
Ohshima's model was developed in 1984 and was originally used to analyze the sedimentation velocity of a single charged sphere and the sedimentation potential of a dilute suspension. The model provided below holds true for dilute suspensions of low zeta potential,
689:
255:
94:
are a family of several different effects that occur in heterogeneous fluids or in porous bodies filled with fluid. The sum of these phenomena deals with the effect on a particle from some outside resulting in a net electrokinetic effect.
928:
Various combinations of the driving force and moving phase determine various electrokinetic effects. Following "Fundamentals of
Interface and Colloid Science" by Lyklema (1995), the complete family of electrokinetic phenomena includes:
387:
114:
in 1879. He observed that a vertical electric field had developed in a suspension of glass beads in water, as the beads were settling. This was the origin of sedimentation potential, which is often referred to as the Dorn effect.
434:
893:
polarization of the resistance electrodes and buildup of charge by alternating the current. The pH of the system could be monitored and the electrolyte was drawn into the tube using a vacuum pump.
263:
is the permitivity of free space, D the dimensionless dielectric constant, ξ the zeta potential, g the acceleration due to gravity, Φ the particle volume fraction, ρ the particle density, ρ
907:
binders, coatings and compounding agents, titanium oxide pigments for paints, paper and textiles, emulsion for soft drinks, and biological materials like viruses and liposomes.
816:
785:
602:
119:
model based on O'Brien and White 's 1978 model used to analyze the sedimentation velocity of a single charged sphere and the sedimentation potential of a dilute suspension.
165:
867:
758:
840:
738:
718:
887:
292:
1265:
102:
Sedimentation potential is the field of electrokinetic phenomena dealing with the generation of an electric field by sedimenting colloid particles.
39:. While the particle moves, the ions in the electric double layer lag behind due to the liquid flow. This causes a slight displacement between the
1223:
Merkus, H. G.; Mori, Y.; Scarlett, B. (1989). "Particle size analysis by sedimentation field flow fractionation. Performance and application".
1170:
Ozaki, Masataka; Ando, Tomoyuki; Mizuno, Kenji (1999). "A new method for the measurement of sedimentation potential: rotating column method".
556:{\displaystyle E_{s}=-{\frac {\varepsilon \zeta (\rho -\rho _{0})\phi _{p}}{\sigma ^{\infty }\eta }}gH(\kappa \alpha )+\vartheta (\zeta ^{2})}
693:
When dealing with the case of concentrated systems, the zeta potential can be determined through measurement of the sedimentation potential
1266:
Stochastic
Modeling of Filtrate Alkalinity in Water Filtration Devices: Transport through Micro/Nano Porous Clay Based Ceramic Materials
1204:
Uddin, S.; Mirnezami, M., and Finch, J.A. "Surface
Characterization of Single and Mixed Mineral Systems using Sedimentation Potential."
136:
where an electric field is applied to the system. Ionic conductivity is often referred to when dealing with sedimentation potential.
1296:
720:, from the potential difference relative to the distance between the electrodes. The other parameters represent the following:
1113:
1090:
1306:
1286:
148:
idea held true for Pyrex glass powder settling in a KCl solution. From this relation, the sedimentation potential, E
994:
as either electric potential or current generated by fluid moving through porous body, or relative to flat surface
575:
67:
1281:
889:
is the acceleration due to gravity; and σ is the electrical conductivity of the bulk electrolyte solution.
1063:
Russel, W.B., Saville, D.A. and
Schowalter, W.R. "Colloidal Dispersions", Cambridge University Press,1989
684:{\displaystyle \zeta ={\frac {\eta \lambda E_{s}}{\varepsilon _{r}\varepsilon _{0}(\rho -\rho _{0})g}}}
36:
794:
763:
250:{\displaystyle E_{s}=-{\frac {\varepsilon \zeta (\rho -\rho _{0})\phi _{p}g}{\sigma ^{\infty }\eta }}}
1301:
999:
1012:
91:
99:
gravity. In addition, the moving phase might be either the continuous fluid or dispersed phase.
1132:
Marlow, Bruce J.; Rowell, Robert L. (1985). "Sedimentation potential in aqueous electrolytes".
845:
52:
743:
1083:
Characterization of liquids, nano- and micro- particulates and porous bodies using
Ultrasound
788:
1291:
825:
723:
696:
111:
412:
8:
989:
20:
382:{\displaystyle \sigma ^{\infty }={\frac {e^{2}}{k_{B}T}}\sum z_{i}^{2}D_{i}n_{i\infty }}
286:
The double-layer thickness 1/κ is small compared to the particle radius a (κa>>1).
1248:
969:
872:
139:
128:
1183:
1054:
Dukhin, S.S. & Derjaguin, B.V. "Electrokinetic
Phenomena", J.Willey and Sons, 1974
984:
as motion of liquid in porous body under influence of the chemical potential gradient
1240:
1187:
1149:
1109:
1086:
979:
1252:
1036:
Lyklema, J. "Fundamentals of
Interface and Colloid Science", vol.2, page.3.208, 1995
1264:
Anand Plappally, Alfred Soboyejo, Norman Fausey, Winston Soboyejo and Larry Brown,"
1232:
1179:
1141:
963:
914:
953:
943:
133:
44:
901:
127:
As a charged particle moves through a gravitational force or centrifugation, an
1072:
Kruyt, H.R. "Colloid Science", Elsevier: Volume 1, Irreversible systems, (1952)
593:
40:
28:
1017:
as ultrasound generated by colloidal particles in oscillating electric field.
1004:
as electric current generated by particles moving in fluid under influence of
1275:
1244:
1191:
1153:
267:
the medium density, λ the specific volume conductivity, and η the viscosity.
83:
48:
35:
in a medium. This motion disrupts the equilibrium symmetry of the particle's
1045:
Hunter, R.J. "Foundations of Colloid Science", Oxford University Press, 1989
55:. The sum of all of the dipoles generates an electric field which is called
819:
59:. It can be measured with an open electrical circuit, which is also called
931:
32:
1145:
1103:
1236:
1105:
Micro- and Nanoscale Fluid Mechanics: Transport in Microfluidic Devices
1005:
584:
958:
as motion of liquid in porous body under influence of electric field
588:
972:
277:
Laminar flow around the particles occurs (Reynolds number <1).
24:
1172:
Colloids and Surfaces A: Physicochemical and Engineering Aspects
915:
Particle size analysis by sedimentation field flow fractionation
66:
There are detailed descriptions of this effect in many books on
902:
Applications of sedimentation field flow fractionation (SFFF)
587:
to a glass column filled with the dispersion of interest. A
270:
Smoluchowski developed the equation under five assumptions:
274:
Particles are spherical, nonconducting, and monodispersed.
948:
as motion of particles under influence of electric field
259:
Smoluchowski's sedimentation potential is defined where ε
416:
Sedimentation Of A Single Particle Generates a Potential
875:
848:
828:
797:
766:
746:
726:
699:
605:
579:
Instrumental Setup to measure Sedimentation Potential
437:
409:
is the number concentration of electrolyte solution.
295:
168:
78:
1222:
881:
861:
834:
810:
779:
752:
732:
712:
683:
555:
381:
249:
152:, is independent of the particle radius and that E
583:Sedimentation potential is measured by attaching
1273:
1169:
51:. As a result, the moving particle creates a
1131:
968:as motion of particles under influence of a
122:
1206:The Minerals, Metals, and Materials Society
1101:
280:Interparticle interactions are negligible.
1218:
1216:
1214:
1127:
1125:
574:
411:
138:
110:This phenomenon was first discovered by
82:
1165:
1163:
1274:
1211:
1075:
1030:
1198:
1122:
1057:
1048:
1039:
1160:
1095:
1066:
398:is the diffusion coefficient of the
143:Macroscopic Diagram of Sedementation
105:
23:move under the influence of either
13:
502:
374:
301:
236:
14:
1318:
1268:" J Nat Env Sci 2010 1(2):96-105.
283:Surface conduction is negligible.
73:
811:{\displaystyle \varepsilon _{0}}
780:{\displaystyle \varepsilon _{r}}
79:Background related to phenomenon
1081:Dukhin, A. S. and Goetz, P. J.
896:
1297:Non-equilibrium thermodynamics
1108:. Cambridge University Press.
672:
653:
570:
550:
537:
528:
519:
482:
463:
213:
194:
1:
1225:Colloid & Polymer Science
1184:10.1016/S0927-7757(99)00278-2
1023:
990:Streaming potential / current
842:the density of the particle;
740:the viscosity of the medium;
68:colloid and interface science
7:
923:
869:the density of the medium;
10:
1323:
1307:Electrochemical potentials
935:Electrokinetic phenomenon
565:
1000:Colloid vibration current
937:
934:
862:{\displaystyle \rho _{0}}
160:→ 0 (a single particle).
123:Generation of a potential
1287:Condensed matter physics
1013:Electric sonic amplitude
753:{\displaystyle \lambda }
92:Electrokinetic phenomena
760:the bulk conductivity;
87:Sedimentation potential
57:sedimentation potential
17:Sedimentation potential
883:
863:
836:
812:
781:
754:
734:
714:
685:
580:
557:
417:
383:
251:
144:
88:
938:Description of event
911:collecting fraction.
884:
864:
837:
835:{\displaystyle \rho }
813:
789:relative permittivity
782:
755:
735:
733:{\displaystyle \eta }
715:
713:{\displaystyle E_{s}}
686:
578:
558:
415:
384:
252:
142:
86:
61:sedimentation current
1102:Kirby, B.J. (2010).
873:
846:
826:
795:
764:
744:
724:
697:
603:
435:
402:solute species, and
293:
166:
1282:Colloidal chemistry
1146:10.1021/la00061a013
355:
21:dispersed particles
1237:10.1007/BF01496931
1085:, Elsevier, 2017
970:chemical potential
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832:
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730:
710:
681:
581:
553:
418:
379:
341:
247:
145:
129:electric potential
89:
1231:(12): 1102–1107.
1115:978-0-521-11903-0
1091:978-0-444-63908-0
1021:
1020:
980:Capillary osmosis
882:{\displaystyle g}
679:
511:
336:
245:
106:History of models
1314:
1302:Electrochemistry
1257:
1256:
1220:
1209:
1202:
1196:
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1178:(2–3): 477–480.
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964:Diffusiophoresis
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954:Electro-osmosis
944:Electrophoresis
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904:
899:
874:
871:
870:
853:
849:
847:
844:
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827:
824:
823:
822:of free space;
802:
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791:of the medium;
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134:electrophoresis
125:
108:
81:
76:
45:electric charge
12:
11:
5:
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636:
628:
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594:zeta potential
572:
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80:
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74:Surface energy
72:
41:surface charge
29:centrifugation
9:
6:
4:
3:
2:
1319:
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1016:
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987:
983:
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951:
947:
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942:
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876:
854:
850:
829:
821:
803:
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790:
772:
768:
747:
727:
705:
701:
675:
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663:
659:
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648:
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71:
69:
64:
62:
58:
54:
53:dipole moment
50:
49:diffuse layer
46:
42:
38:
34:
30:
26:
22:
18:
1228:
1224:
1205:
1200:
1175:
1171:
1140:(1): 83–90.
1137:
1133:
1104:
1097:
1082:
1077:
1068:
1059:
1050:
1041:
1032:
927:
918:
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905:
897:Applications
891:
820:permittivity
692:
582:
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269:
258:
146:
126:
117:
109:
101:
97:
90:
65:
60:
56:
37:double layer
19:occurs when
16:
15:
1292:Soft matter
571:Measurement
33:electricity
1276:Categories
1024:References
1006:ultrasound
585:electrodes
1245:0303-402X
1192:0927-7757
1154:0743-7463
851:ρ
830:ρ
800:ε
769:ε
748:λ
728:η
664:ρ
660:−
657:ρ
645:ε
635:ε
619:λ
616:η
607:ζ
589:voltmeter
542:ζ
535:ϑ
526:α
523:κ
508:η
503:∞
499:σ
487:ϕ
474:ρ
470:−
467:ρ
461:ζ
458:ε
452:−
375:∞
339:∑
302:∞
298:σ
242:η
237:∞
233:σ
218:ϕ
205:ρ
201:−
198:ρ
192:ζ
189:ε
183:−
1253:98181572
1134:Langmuir
973:gradient
924:See also
43:and the
566:Testing
156:→ 0, Φ
47:of the
25:gravity
1251:
1243:
1190:
1152:
1112:
1089:
423:i.e. e
391:Where
1249:S2CID
429:T ≤2
1241:ISSN
1208:2010
1188:ISSN
1150:ISSN
1110:ISBN
1087:ISBN
818:the
787:the
112:Dorn
1233:doi
1229:267
1180:doi
1176:159
1142:doi
425:ζ/κ
400:ith
31:or
27:or
1278::
1247:.
1239:.
1227:.
1213:^
1186:.
1174:.
1162:^
1148:.
1136:.
1124:^
406:i∞
70:.
63:.
1255:.
1235::
1194:.
1182::
1156:.
1144::
1138:1
1118:.
877:g
855:0
804:0
773:r
706:s
702:E
676:g
673:)
668:0
654:(
649:0
639:r
627:s
623:E
610:=
551:)
546:2
538:(
532:+
529:)
520:(
517:H
514:g
491:p
483:)
478:0
464:(
449:=
444:s
440:E
427:B
404:n
395:i
393:D
372:i
368:n
362:i
358:D
352:2
347:i
343:z
333:T
328:B
324:k
317:2
313:e
307:=
265:o
261:0
227:g
222:p
214:)
209:0
195:(
180:=
175:s
171:E
158:p
154:S
150:S
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