PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 16090355

Model for reversible colloidal gelation.

E Zaccarelli·S V Buldyrev·E La Nave·A J Moreno·I Saika-Voivod·F Sciortino·P Tartaglia
View original source ↗Export metadata ↓

Abstract

We report a numerical study, covering a wide range of packing fraction Phi and temperature T, for a system of particles interacting via a square well potential supplemented by an additional constraint on the maximum number n(max) of bonded interactions. We show that, when n(max)<6, the liquid-gas coexistence region shrinks, giving access to regions of low Phi where dynamics can be followed down to low T without an intervening phase separation. We characterize these arrested states at low densities (gel states) in terms of structure and dynamical slowing down, pointing out features which are very different from the standard glassy states observed at high Phi values.

Explore related subjects

BiophysicsColloidsGelsModels, TheoreticalTemperatureViscosityJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

E Zaccarelli, S V Buldyrev, E La Nave, A J Moreno, I Saika-Voivod, F Sciortino, P Tartaglia. 2005-06-02. Model for reversible colloidal gelation.. https://doi.org/10.1103/physrevlett.94.218301

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

Under the microscope: single molecule symposium at the University of Michigan, 2006.

In recent years, a revolution has occurred in the basic sciences, which exploits novel single molecule detection and manipulation tools to track and analyze biopolymers in unprecedented detail. A recent Gordon Research Conference style meeting, hosted by the University of Michigan, highlighted current status and future perspectives of this rising field as researchers begin to integrate it with mainstream biology and nanotechnology.

Biophysics↗
PubMed2007

Red antenna states of photosystem I from cyanobacteria Synechocystis PCC 6803 and Thermosynechococcus elongatus: single-complex spectroscopy and spectral hole-burning study.

Hole-burning and single photosynthetic complex spectroscopy were used to study the excitonic structure and excitation energy-transfer processes of cyanobacterial trimeric Photosystem I (PS I) complexes from Synechocystis PCC 6803 and Thermosynechococcus elongatus at low temperatures. It was shown that individual PS I complexes of Synechocystis PCC 6803 (which have two red antenna states, i.e., C706 and C714) reveal only a broad structureless fluorescence band with a maximum near 720 nm, indicating strong electron-phonon coupling for the lowest energy C714 red state. The absence of zero-phonon lines (ZPLs) belonging to the C706 red state in the emission spectra of individual PS I complexes from Synechocystis PCC 6803 suggests that the C706 and C714 red antenna states of Synechocystis PCC 6803 are connected by efficient energy transfer with a characteristic transfer time of approximately 5 ps. This finding is in agreement with spectral hole-burning data obtained for bulk samples of Synechocystis PCC 6803. The importance of comparing the results of ensemble (spectral hole burning) and single-complex measurements was demonstrated. The presence of narrow ZPLs near 710 nm in addition to the broad fluorescence band at approximately 730 nm in Thermosynechococcus elongatus (Jelezko et al. J. Phys. Chem. B 2000, 104, 8093-8096) has been confirmed. We also demonstrate that high-quality samples obtained by dissolving crystals of PS I of Thermosynechococcus elongatus exhibit stronger absorption in the red antenna region than any samples studied so far by us and other groups.

Biophysics↗