Dataset Information

Reversible Adsorption Kinetics of Near Surface Dimer Colloids.

ABSTRACT: We investigate the effect of shape on reversible adsorption kinetics using colloidal polystyrene dimers near a solid glass surface as a model system. The interaction between colloid and wall is tuned using electrostatic, depletion, and gravity forces to produce a double-well potential. The dwell time in each of the potential wells is measured from long duration particle trajectories. The height of each monomer relative to the glass surface is measured to a resolution of <20 nm by in-line holographic microscopy. The measured transition probability distributions are used in kinetic equations to describe the flux of particles to and from the surface. The dimers are compared to independent isolated monomers to determine the effects of shape on adsorption equilibria and kinetics. To elucidate these differences, we consider both mass and surface coverage and two definitions of surface coverage. The results show that dimers with single coverage produce slower adsorption, lower surface coverage, and higher mass coverage in comparison to those of monomers, while dimers with double coverage adsorb faster and result in higher surface coverage.

SUBMITTER: Salipante PF

PROVIDER: S-EPMC5064446 | biostudies-other | 2016 Aug

REPOSITORIES: biostudies-other

ACCESS DATA

Publications

Reversible Adsorption Kinetics of Near Surface Dimer Colloids.

Salipante Paul F PF Hudson Steven D SD

Langmuir : the ACS journal of surfaces and colloids 20160817 34

We investigate the effect of shape on reversible adsorption kinetics using colloidal polystyrene dimers near a solid glass surface as a model system. The interaction between colloid and wall is tuned using electrostatic, depletion, and gravity forces to produce a double-well potential. The dwell time in each of the potential wells is measured from long duration particle trajectories. The height of each monomer relative to the glass surface is measured to a resolution of <20 nm by in-line hologra ...[more]

PMID: 27483023

Similar Datasets

Project description:Environment-friendly composite hydrogel beads based on carboxymethyl cellulose (CMC), alginate (Alg) and graphene oxide (GO) were synthesized by an ionotropic gelation technique and studied as an efficient adsorbent for methylene blue (MB). The chemical structure and surface morphology of the prepared hydrogel beads were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), differential thermal analysis (DTA) and point of zero charge (pHpzc). A hybrid response surface methodology integrated Box-Behnken design (RSM-BBD) was successfully developed to model, simulate, and optimize the biosorption process. The synergistic effects between three critical independent variables including adsorbent dose (0.3-0.7 g), pH of the MB solution (6.5-9.5) and initial MB concentration (15-45 mg L-1) on the MB adsorption capacity (mg g-1) and removal efficiency (%) were statistically studied and optimized. The performance of the RSM-BBD method was found to be very impressive and efficient. Results proved that the adsorption process follows a polynomial quadratic model since high regression parameters were obtained (R 2-value = 99.8% and adjusted R 2-value = 99.3%). Analysis of variance (ANOVA) further confirms the validity of the suggested model. The optimal conditions for 96.22 ± 2.96% MB removal were predicted to be 0.6 g of CMC-Alg/GO hydrogel beads, MB concentration of 15 mg L-1 and pH of 9.5 within 120 min. The adsorption equilibrium is better described by the Freundlich isotherm, indicating that physisorption is the rate controlling mechanism. The MB adsorption process was thermodynamically spontaneous and endothermic. A reusability study revealed that the prepared adsorbent is readily reusable. The adsorbent still maintains its ability to adsorb MB for up to four cycles. Results reported in this study demonstrated that CMC-Alg/GO hydrogel beads are an effective, promising and recyclable adsorbent for the removal of MB from aqueous solutions.

Dataset Information

Reversible Adsorption Kinetics of Near Surface Dimer Colloids.

Publications

Reversible Adsorption Kinetics of Near Surface Dimer Colloids.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets