Crystallization of bidisperse repulsive colloids in two-dimensional space : a study of model systems constructed at the air-water interface

We report the structural behavior for mixtures of two differently sized ("bidisperse") silica microspheres at the air-water interface under three different size ratio conditions (alpha (identical with R(S)/R(L)) = 0.375, 0.500, and 0.579). These bidisperse silica monolayers were studied vi...

Ausführliche Beschreibung

Bibliographische Detailangaben
Veröffentlicht in:Langmuir : the ACS journal of surfaces and colloids. - 1991. - 26(2010), 14 vom: 20. Juli, Seite 11737-49
1. Verfasser: Hur, Jaehyun (VerfasserIn)
Weitere Verfasser: Mahynski, Nathan A, Won, You-Yeon
Format: Online-Aufsatz
Sprache:English
Veröffentlicht: 2010
Zugriff auf das übergeordnete Werk:Langmuir : the ACS journal of surfaces and colloids
Schlagworte:Journal Article
LEADER 01000caa a22002652 4500
001 NLM198626959
003 DE-627
005 20250211152311.0
007 cr uuu---uuuuu
008 231223s2010 xx |||||o 00| ||eng c
024 7 |a 10.1021/la101313r  |2 doi 
028 5 2 |a pubmed25n0662.xml 
035 |a (DE-627)NLM198626959 
035 |a (NLM)20527939 
040 |a DE-627  |b ger  |c DE-627  |e rakwb 
041 |a eng 
100 1 |a Hur, Jaehyun  |e verfasserin  |4 aut 
245 1 0 |a Crystallization of bidisperse repulsive colloids in two-dimensional space  |b a study of model systems constructed at the air-water interface 
264 1 |c 2010 
336 |a Text  |b txt  |2 rdacontent 
337 |a ƒaComputermedien  |b c  |2 rdamedia 
338 |a ƒa Online-Ressource  |b cr  |2 rdacarrier 
500 |a Date Completed 01.12.2010 
500 |a Date Revised 29.07.2010 
500 |a published: Print 
500 |a Citation Status PubMed-not-MEDLINE 
520 |a We report the structural behavior for mixtures of two differently sized ("bidisperse") silica microspheres at the air-water interface under three different size ratio conditions (alpha (identical with R(S)/R(L)) = 0.375, 0.500, and 0.579). These bidisperse silica monolayers were studied via measurement of the surface pressure-area isotherm and optical microscopy at various particle surface coverages (theta identical with theta(S) + theta(L)) during compression. The silica colloids used in these trials were found to possess purely repulsive pair interactions at the air-water interface, which was confirmed by the pair correlation function calculated from the analysis of many optical images of the particles taken at dilute concentrations. The results revealed that, at certain mixture compositions (beta identical with theta(L)/theta(S)), compression can lead to the formation of 2D binary crystal structures. Specifically, at a particle size ratio of alpha = 0.375, LS1 crystal domains were observed at a surface coverage of theta approximately 0.619 when beta = 7.00 and 3.50, although this LS1 structure was not observed at higher total particle densities (where the system became phase-separated). At a size ratio of alpha = 0.579, compression produced 2D LS2 binary crystals at particle surface coverages (theta) above 0.641 when beta = 3.00, 1.50, or 1.00. However, at a size ratio of alpha = 0.500, compression triggered macroscopic phase separation, leading to the formation of two separate hexagonal-close-packed domains consisting purely of either large or small particles. In general, when the mixture composition (beta) was too different from the stoichiometric ratio needed for the formation of LS1 or LS2 superlattices, the bidisperse monolayer was observed to remain in an amorphous state rather than evolving to an ordered phase under compression. These findings suggest that, in two dimensions, contrary to what has been speculated in the literature, (1) purely repulsive pair potentials can give rise to LS1 and LS2 binary crystals under compression and also (2) perfectly spherical particles can form LS2 crystals. This discrepancy between our results and the predictions of previous simulations might indicate that the capillary interaction and/or the many-body effects play a significant role in determining the structure of bidisperse colloids at the air-water interface 
650 4 |a Journal Article 
700 1 |a Mahynski, Nathan A  |e verfasserin  |4 aut 
700 1 |a Won, You-Yeon  |e verfasserin  |4 aut 
773 0 8 |i Enthalten in  |t Langmuir : the ACS journal of surfaces and colloids  |d 1991  |g 26(2010), 14 vom: 20. Juli, Seite 11737-49  |w (DE-627)NLM098181009  |x 1520-5827  |7 nnns 
773 1 8 |g volume:26  |g year:2010  |g number:14  |g day:20  |g month:07  |g pages:11737-49 
856 4 0 |u http://dx.doi.org/10.1021/la101313r  |3 Volltext 
912 |a GBV_USEFLAG_A 
912 |a SYSFLAG_A 
912 |a GBV_NLM 
912 |a GBV_ILN_22 
912 |a GBV_ILN_350 
912 |a GBV_ILN_721 
951 |a AR 
952 |d 26  |j 2010  |e 14  |b 20  |c 07  |h 11737-49