Fluorescence Correlation Spectroscopy Study of Probe Diffusion in Poly(Vinyl Alcohol) Solutions and Gels
نویسندگان
چکیده
In this study, we demonstrate how the diffusion of probe particles in aqueous poly(vinyl alcohol) (PVA) solutions and gels is affected by: (i) the presence of cross-links, (ii) the cross-link density, (iii) the polymer concentration. We apply fluorescence correlation spectroscopy (FCS) to measure the diffusion time of a rhodamine-based fluorescent particle (TAMRA) and TAMRA-labeled dextran in PVA solutions and gels prepared at various polymer concentrations (1% to 8.6% w/v) and cross-link densities (1/400 to 1/50 cross-link monomers per PVA monomers). The measurements indicate that the probe particles are slowed down with increasing polymer concentration and with increasing cross-link density. Also, FCS can detect differences in the diffusion times measured in “fresh” and “aged” PVA solutions. We find that FCS provides a quantitative measure of network inhomogeneities.
منابع مشابه
Structural Changes in Polymer Gels Probed by Fluorescence Correlation Spectroscopy
Introduction Previous studies, e.g., by NMR,1,2 fluorescence pho tobleaching,3 and dynamic light scattering (DLS),4,5 have shown that the diffusion of noninteracting probe particles in polymer solutions and gels primarily de pends on the polymer concentration and the size of the probe. In interpreting these results, it is widely assumed that polymer gels behave like semidilute polymer solu t...
متن کاملProbe diffusion in aqueous poly(vinyl alcohol) solutions studied by fluorescence correlation spectroscopy.
We report fluorescence correlation spectroscopy measurements of the translational diffusion coefficient of various probe particles in dilute and semidilute aqueous poly(vinyl alcohol) solutions. The range of sizes of the particles (fluorescent molecules, proteins, and polymers) was chosen to explore various length scales of the polymer solutions as defined by the polymer-polymer correlation len...
متن کاملNanoprobe Diffusion in Poly(Vinyl-alcohol) Gels and Solutions: Effects of pH and Dehydration
We report fluorescence correlation spectroscopy (FCS) measurements of the translational diffusion of two fluorescent nanoprobes, rhodamine (R6G) and carboxytetramethylrhodamine (TAMRA), embedded in poly(vinyl alcohol) (PVA) solutions and gels. The diffusion coefficient was measured as a function of the PVA concentration and pH. Furthermore, we designed and built an optical chamber to determine ...
متن کاملFluorescence Correlation Spectroscopy Study of TAMRA Diffusion in Poly(vinyl-alcohol) and Ficoll70 Solutions.
We compare fluorescence correlation spectroscopy (FCS) measurements of the fluorescent nanoparticle, TAMRA, diffusing in non-fluorescent -hence invisiblepoly(vinylalcohol) (PVA) or Ficoll70 solutions as a function of the polymer concentration, c. We determine changes of the translational diffusion coefficient of TAMRA and fit the data with the universal scaling law ( ] ) / ( exp[ ~ * ν α c c D ...
متن کاملProbe Diffusion in Pva Solutions and Gels Studied by Fluorescence Correlation Spectroscopy
Introduction. It has been shown in previous studies, e.g., by NMR, fluorescence photobleaching, and dynamic light scattering (DLS), that the diffusion of non-interacting probe particles in polymer solutions and gels primarily depends on the polymer concentration and the size of the probe. In interpreting these results, it is widely assumed that polymer gels behave like semi-dilute polymer solut...
متن کامل