No CrossRef data available.
Published online by Cambridge University Press: 22 February 2011
Asphaltic materials are used as binders for road asphalts. Such materials have been found to contain a dispersed phase of colloidal particles in the size range of 50-100 Å, according to small angle X-ray scattering(SAXS) techniques. The presence of this dispersed phase has a significant influence on the rheological properties of these materials. These colloidal particles can be isolated by precipitation with heptane, and so they are associated with the well-known asphaltene solubility class in some manner. In this work we review previously published results that suggest that at least part of the asphaltenes are surface active agents in certain solvents such as toluene, or pyridine, and can form micelles in these solvents. Small angle neutron scattering (SANS) indicates the micelles are spherical with average radii in the 50-100 Å range. There is a polydispersity of sizes. The micelles do not grow in these solvents with increasing concentration in the range of 1-10 wt.%, nor do they dissociate on heating to ~ 170 °C. At higher concentrations, however, a more complicated structure develops. The micelles aggregate to form a large cluster composed of micelles. The fractal dimension of the clusters is found to be 1.8.
To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.
To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.