Zeta potentials of PDMS surfaces modified with poly(ethylene glycol) by physisorption

Abstract

Controlling zeta potential of PDMS surface coated with a layer of PEG is important for electroosmosis and electrophoresis in PDMS made microfluidic chips. Here, zeta potentials of PDMS surfaces modified by simple physisorption of PEG of different concentrations in phosphate buffer solutions, pure water, and PEG solution were reported. Coating PEG on PDMS surfaces was achieved by immersing a PDMS layer into the PEG solution for 10 min and then taking it out and placing it in an oven at 80 • C for 10 h. To avoid damaging the PEG layer on the PDMS surface, an induction current method was employed for zeta potential measurement. Zeta potentials of PEG modified PDMS in electrolyte solutions were measured. The results show that 2.5% PEG can effectively modify PDMS surface with positive zeta potential value in phosphate buffer solutions, pure water and 10% PEG solution. Further increase in PEG solution beyond 5% for surface modification has no obvious effect on zeta potential change.

Protein Patterning on Microtextured Polymeric Nanobrush Templates Obtained by Nanosecond Fiber Laser

“…[56,57] The positive value suggests that polyPEGMA chains block the adsorption site on the surface of Ti a surface as supported by other literatures too. [56,57] However, patterning the Ti a -g-PPEGMA surface made a change in surface charges from +6.1 to −2.2 mV, exhibiting a charge reversal upon laser texturing. It was presumed that post laser ablation, the patterned Ti a area may form oxide layer when exposed to ambient conditions, thus lowering the zeta potential.…”

Influence of surface charge on the formulation of elongated PEG-b-PDLLA nanoparticles

“…44 All particles possessed a negative zeta-potential due to the negative character of poly(ethylene glycol)-rich membranes in solution, which was diminished in case of the amine-containing polymersomes. [45][46][47] No significant difference in zetapotential was observed between unmodified and CA-modified polymersomes. Although the zeta-potential values did not yield major differences between the different polymersomal formulations in terms of surface charge, the presence of carboxylic acid and primary amine groups at the surface of polymersomes could still induce different interactions in a biological context.…”

Nickel-Embedded Carbon Materials Derived from Wheat Flour for Li-Ion Storage

“…As for the prepared NC-600 and NC-800, three sharp diffraction peaks at 2θ = 44.5, 51.8, and 76.4° are observed, which could be assigned to the lattice planes of (111), (200), and (220) for nickel metal with (Fm-3m) space group (JCPDS card 65-2865), respectively [ 36 , 37 , 38 , 39 ]. The metallic nickel is formed via a reduction reaction of Ni (NO 3 ) 2 by the surrounding carbon atoms under high carbonization temperature [ 40 , 41 ]. It is well-known that the crystalline structure of the carbon anode materials, for example, the (002) lattice plane, significantly influences the intercalation/de-intercalation of Li + .…”