In:
The Journal of Chemical Physics, AIP Publishing, Vol. 139, No. 6 ( 2013-08-14)
Abstract:
Five groups of suspensions composed of polystyrene particles, having similar size but different effective surface charge, were adopted to investigate the effects of surface charge and volume fraction on the homogeneity of colloidal crystals through checking the difference between Dexp and Duni by reflection spectroscopy method (Dexp, Duni are the experimental and the expected value of the average nearest neighbor interparticle distance by assuming a uniform structure, respectively). We found volume fractions (ranging from 0.006 to 0.02) and structure types basically have no influence on the values of Dexp/Duni. Moreover, for crystals formed by lowly charged particles, Dexp/Duni is approximately equal to 1, implying the crystals are homogeneous. With the increase of effective surface charge, Dexp gradually deviates from Duni and the formed crystals become inhomogeneous. Our experimental observations are in accordance with the previous simulation results. Additionally, we also found Dexp/Duni initially drops quickly with increasing effective surface charge and then it tends to an asymptotic value (∼0.85), it is supposedly due to the saturation of effective charge. Our relevant computer simulations confirmed that the study scheme that using Dexp/Duni as an indicator to assess the homogeneity of crystal structure is tenable and the simulation results are consistent with experiments.
Type of Medium:
Online Resource
ISSN:
0021-9606
,
1089-7690
Language:
English
Publisher:
AIP Publishing
Publication Date:
2013
detail.hit.zdb_id:
3113-6
detail.hit.zdb_id:
1473050-9
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