Effect of Electric Field on the Mobility of Carboxyl-Terminated Dendrimers

Seyrek, Emek; Dubin, Paul L.; Newkome, George R.

doi:10.1021/jp0380071

Cited by 25 publications

(34 citation statements)

References 20 publications

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“…17 However, this scenario fails to explain our results for the DELSA standard EMPSL7 and is also inconsistent with strong effects of field on mobility of dendrimers in the absence of Joule heating. 16 The mobilities of BSA and CF(3.0) are almost independent of E especially when E < 370 V/cm, and the values of µ obtained by CE at 370 V/cm agree well with those from ELS ( Figure 6). Thus, it should be possible to compare the CE data for CF3.0, CF4.6, and CF7.3 measured at E ) 185 V/cm to the ELS data for CF400 samples.…”

Section: Resultssupporting

confidence: 73%

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Carboxylated Ficolls: Preparation, Characterization, and Electrophoretic Behavior of Model Charged Nanospheres

2006

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Carboxylated ficolls were prepared as model spherical colloids of variable charge and size, with radii ranging from 3.0 to 19.3 nm. Capillary electrophoresis (CE), electrophoretic light scattering (ELS), and potentiometric titration were used to determine mobilities as a function of pH, degree of ionization R, and surface potential ψ 0 . Measured mobilities typically display a plateau at high pH, corresponding to high R and ψ 0 , confirming the general nature of this effect for charged spheres, seen also for charged dendrimers and charged latex particles. This result is examined in the context of a discontinuity in mobility predicted by the Wiersema, O'Brien, and White (WOW) theory and a more recent primitive model electrophoresis (PME) theory, in which bound counterions are considered either as point charges or as hard spheres. While no mobility maximum can be determined as expected by these two theories, our data seem more to support Belloni's theoretical expectations on charged polymers and spheres. Here we explain the mobility plateaus in terms of counterions accumulated close to the surface (surface potential-determining ions) or within the shear plane (mobilitydetermining ions).

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Section: Resultssupporting

confidence: 73%

“…As showed in Figure 5, mobility for several solutes depends on E, but the slope depends on samples. 16 The mobility of EMPSL7 decreased with increasing E as it deviates from the standard value of …”

Section: Resultsmentioning

confidence: 92%

Carboxylated Ficolls: Preparation, Characterization, and Electrophoretic Behavior of Model Charged Nanospheres

2006

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“…Consequently, the apparent EM of PAMAM-SAHs increases with the number of dendrimer generations (Table 1). Carboxyl-terminated dendrimers often experience a counterion binding effect when subjected to separation under an electric field [26,32,33]. The counterion binding effect, in certain circumstances, could play an important role in the separation of dendrimers.…”

Section: Resultsmentioning

confidence: 99%

CE of poly(amidoamine) succinamic acid dendrimers using a poly(vinyl alcohol)‐coated capillary

2008

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Various generations (G1-G8) of negatively charged poly(amidoamine) (PAMAM) succinamic acid dendrimers (PAMAM-SAH) were analyzed by CE using a poly(vinyl alcohol)-coated capillary. Due to its excellent stability and osmotic flow-shielding effect, highly reproducible migration times were achieved for all generations of dendrimer (e.g., RSD for the migration times of G5 dendrimer was 0.6%). We also observed a reverse trend in migration times for the PAMAM-SAH dendrimers (i.e., higher generations migrated faster than lower generation dendrimers) compared to amine-terminated PAMAM dendrimers reported in the literature. This reversal in migration times was attributed to the difference in counterion binding around these negatively charged dendrimers. This reverse trend allowed a generational separation for lower generation (G1-G3) dendrimers. However, a sufficient resolution for the migration peaks of higher generations (G4-G5) in a mixture could not be achieved. This could be due to their nearly identical charge/mass ratio and dense molecular conformations. In addition, we show that dye-functionalized PAMAM-SAH dendrimers can also be analyzed with high reproducibility using this method.

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“…As a result, the retardation force disappears, and the electrophoretic mobility increases correspondingly. This nonlinear electrokinetic effect at high electric fields is observed for electrolytes (the first Wien effect) [17][18][19], colloids in polar liquids [20,21], and colloids in nonpolar liquids [22][23][24].…”

Section: Introductionmentioning

confidence: 99%

Electrophoretic Retardation of Colloidal Particles in Nonpolar Liquids

et al. 2013

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We have measured the electrophoretic mobility of single, optically trapped colloidal particles, while gradually depleting the co-ions and counterions in the liquid around the particle by applying a dc voltage. This is achieved in a nonpolar liquid, where charged reverse micelles act as co-ions and counterions. By increasing the dc voltage, the mobility first increases when the concentrations of co-ions and counterions near the particle start to decrease. At sufficiently high dc voltage (around 2 V), the mobility reaches a saturation value when the co-ions and counterions are fully separated. The increase in mobility is larger when the equilibrium ionic strength is higher. The dependence of the experimental data on the equilibrium ionic strength and on the applied voltage is in good agreement with the standard theory of electrophoretic retardation, assuming that the bare particle charge remains constant. This method is useful for studying the electrophoretic retardation effect and charging mechanisms for nonpolar colloids, and it sheds light on previously unexplained particle acceleration in electronic ink devices.

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Effect of Electric Field on the Mobility of Carboxyl-Terminated Dendrimers

Cited by 25 publications

References 20 publications

Carboxylated Ficolls: Preparation, Characterization, and Electrophoretic Behavior of Model Charged Nanospheres

Carboxylated Ficolls: Preparation, Characterization, and Electrophoretic Behavior of Model Charged Nanospheres

CE of poly(amidoamine) succinamic acid dendrimers using a poly(vinyl alcohol)‐coated capillary

Electrophoretic Retardation of Colloidal Particles in Nonpolar Liquids

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