{"id":3418,"date":"2011-07-21T23:58:56","date_gmt":"2011-07-21T15:58:56","guid":{"rendered":"http:\/\/www.andrewsun.net\/panta_rhei\/?p=3418"},"modified":"2011-07-22T23:52:45","modified_gmt":"2011-07-22T15:52:45","slug":"rheometry-of-laponitepeo-suspensions","status":"publish","type":"post","link":"https:\/\/www.andrewsun.net\/panta_rhei\/archives\/3418","title":{"rendered":"Rheometry of Laponite\/PEO suspensions"},"content":{"rendered":"
\n

A full lest of rheometric investigation of Laponite\/PEG suspension. Parts of the tasks have been submitted or published.<\/p>\n

Observation during preshear<\/h1>\n

Comparison of different shear rates<\/h3>\n

Steady shear flow [math]\\eta[\/math] vs [math]\\dot{\\gamma}[\/math]. Procedure: steady preshear at [math]\\dot{\\gamma}[\/math] = 200 s-1<\/sup> for 200s, delay for 800s, steady state flow test.<\/p>\n

Samples: L2S5, L2S5P35k0.1, 0.25, 0.63, 0.8, 1.0<\/p>\n

Instrument: AR-G2<\/p>\n

Comparison of different shear method: osc. vs cont.<\/h3>\n

Whether [math]\\gamma_0\\omega=\\dot{\\gamma}[\/math], by checking the Cox-Merz rule<\/p>\n

Sample: L2S5, L2S5P35k0.63<\/p>\n

Instrument: AR-G2<\/p>\n

Aging<\/h1>\n

Ageing under SAOS<\/h2>\n

Comparison of different preshear rates<\/h3>\n

Procedure: Steady preshear at [math]\\dot{\\gamma}[\/math] = 1, 2.5, 6.3, 16, 40, 63, 160, 200 s-1<\/sup> for 200 s, oscillatory time sweep.<\/p>\n

Samples: L2S5, L2S5P35k0.1, 0.25, 0.63, 0.8, 1.0<\/p>\n

Instrument: AR-G2<\/p>\n

Comparison of different preshear method: osc. vs cont.<\/h3>\n

Procedure: preshear at [math]\\dot{\\gamma}[\/math] = 200 s-1<\/sup> or \u03b3<\/em> = 200 %, \u03c9<\/em> = 10 rad\/s, for 200 s, oscillatory frequency sweep.<\/p>\n

Samples: L2S5, L2S5P35k0.63<\/p>\n

Instrument: AR-G2<\/p>\n

Effect of PEG concentration<\/h3>\n

Submitted.<\/p>\n

Time-resolved viscoelastic property<\/h3>\n

Procedure: steady preshear at [math]\\dot{\\gamma}[\/math] = 200 s-1<\/sup> for 200 s, oscillatory time sweep at \u03c9 = 1, 1.6, 2.5, 4, 6.3, 10, 16, 25, 40, 63 rad\/s for 400s.<\/p>\n

Samples: L2S5P35k0.1, 0.25, 0.63, 0.8, 1.0<\/p>\n

Instrument: AR-G2<\/p>\n

Aging under LAOS<\/h2>\n

Procedure: steady preshear at [math]\\dot{\\gamma}[\/math] = 200 s-1<\/sup> for 200 s, dynamic time sweep at \u03c9<\/em> = 6.283 rad\/s and \u03b3<\/em>0<\/sub> = 1 ~ 25 %, focusing on the yielding strain amplitude region.<\/p>\n

Samples: L2S5P35k0.063, 0.1, 0.25, 0.4, 0.63, 1.0<\/p>\n

Instrument: ARES<\/p>\n

Aged gel<\/h1>\n

Steady LAOS<\/h2>\n

Published.<\/p>\n

Yielding under LAOS<\/h2>\n

References: PRL<\/i> 2011<\/b>, 106<\/i>, 248303. Soft Matter<\/i> 2010<\/b>, 6<\/i>, 3482.
\nProcedure: steady preshear at [math]\\dot{\\gamma}[\/math] = 200 s-1<\/sup> for 200s, delay 800s, arbitrary waveshape test at \u03c9<\/em> = 6.283 rad\/s and \u03b3<\/em>0<\/sub> = 10 ~ 100 % focusing on the yielding regime.<\/p>\n

Samples: L2S5P35k0.1, 0.25, 0.4, 0.63, 0.8, 1.0<\/p>\n

Instrument: ARES<\/p>\n

Schedule<\/h1>\n