東華大學圖書館 |

Language: English

Help

回圖書館首頁

手機版館藏查詢

Back

Switch To: Labeled | MARC Mode | ISBD

Nanoparticle engineering of colloida...

Chan, Angel Thanda.

Linked to FindBook

Google Book

Amazon

博客來

Nanoparticle engineering of colloidal suspension behavior.

Record Type:	Language materials, printed : Monograph/item
Title/Author:	Nanoparticle engineering of colloidal suspension behavior./
Author:	Chan, Angel Thanda.
Description:	126 p.
Notes:	Adviser: Jennifer A. Lewis.
Contained By:	Dissertation Abstracts International69-02B.
Subject:	Chemistry, Pharmaceutical. -
Online resource:	http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3301261
ISBN:	9780549463795

Nanoparticle engineering of colloidal suspension behavior.
Chan, Angel Thanda.

Nanoparticle engineering of colloidal suspension behavior. - 126 p.

Adviser: Jennifer A. Lewis.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007.

We investigate the effects of highly charged nanoparticles on the phase behavior, structure, and assembly of colloidal microsphere suspensions. Specifically, by selectively tuning the electrostatic interactions between silica microspheres and polystyrene nanoparticles, we study the behavior of four key systems: (i) strongly repulsive, (ii) haloing, (iii) weakly attractive, and (iv) strongly attractive systems. In each system, a combination of nanoparticle adsorption, zeta potential, and confocal microscopy measurements are carried out to systematically study the effects of nanoparticle volume fraction, microsphere/nanoparticle size ratios, and interparticle interactions on their behavior. Our observations indicate that minimal adsorption of highly charged nanoparticles occurs on like-charged and negligibly-charged microspheres, whereas their extent of association increases dramatically with increasing microsphere-nanoparticle attraction. A rich phase behavior emerges in these systems based on whether the nanoparticle species serve as depletants, haloing, or bridging species. The phase transitions in the haloing system occur at constant nanoparticle volume fractions, &phis;nano, over a broad range of microsphere volume fractions, &phis;micro . By contrast, the observed transitions in the weakly and strongly attractive mixtures occur at a constant number ratio of nanoparticles per microsphere, Nnano/Nmicro. Important structural differences emerge, which can be exploited in the assembly of colloidal gels for direct ink writing and colloidal crystals on epitaxially patterned substrates. Finally, for the first time, we explore nanoparticle haloing as a new route for stabilizing hydrophobic colloidal drugs in aqueous suspensions media for preparation of injectable pharmaceuticals. These microsphere suspensions exhibit improved stability relative to their surfactant-stabilized counterparts after autoclaving, a critical processing step for this target applications. This research opens up a new avenue for stabilization of hydrophobic particles, when surfactant additions alone do not provide sufficient stabilization.

ISBN: 9780549463795Subjects--Topical Terms:

550957
Chemistry, Pharmaceutical.

Nanoparticle engineering of colloidal suspension behavior.
LDR:03030nam 2200277 a 45 001 942040
005 20110519
008 110519s2007 ||||||||||||||||| ||eng d
020 $a 9780549463795
035 $a (UMI)AAI3301261
035 $a AAI3301261
040 $a UMI $c UMI
100 1 $a Chan, Angel Thanda. $3 1266139
245 1 0 $a Nanoparticle engineering of colloidal suspension behavior.
300 $a 126 p.
500 $a Adviser: Jennifer A. Lewis.
500 $a Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 1255.
502 $a Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2007.
520 $a We investigate the effects of highly charged nanoparticles on the phase behavior, structure, and assembly of colloidal microsphere suspensions. Specifically, by selectively tuning the electrostatic interactions between silica microspheres and polystyrene nanoparticles, we study the behavior of four key systems: (i) strongly repulsive, (ii) haloing, (iii) weakly attractive, and (iv) strongly attractive systems. In each system, a combination of nanoparticle adsorption, zeta potential, and confocal microscopy measurements are carried out to systematically study the effects of nanoparticle volume fraction, microsphere/nanoparticle size ratios, and interparticle interactions on their behavior. Our observations indicate that minimal adsorption of highly charged nanoparticles occurs on like-charged and negligibly-charged microspheres, whereas their extent of association increases dramatically with increasing microsphere-nanoparticle attraction. A rich phase behavior emerges in these systems based on whether the nanoparticle species serve as depletants, haloing, or bridging species. The phase transitions in the haloing system occur at constant nanoparticle volume fractions, &phis;nano, over a broad range of microsphere volume fractions, &phis;micro . By contrast, the observed transitions in the weakly and strongly attractive mixtures occur at a constant number ratio of nanoparticles per microsphere, Nnano/Nmicro. Important structural differences emerge, which can be exploited in the assembly of colloidal gels for direct ink writing and colloidal crystals on epitaxially patterned substrates. Finally, for the first time, we explore nanoparticle haloing as a new route for stabilizing hydrophobic colloidal drugs in aqueous suspensions media for preparation of injectable pharmaceuticals. These microsphere suspensions exhibit improved stability relative to their surfactant-stabilized counterparts after autoclaving, a critical processing step for this target applications. This research opens up a new avenue for stabilization of hydrophobic particles, when surfactant additions alone do not provide sufficient stabilization.
590 $a School code: 0090.
650 4 $a Chemistry, Pharmaceutical. $3 550957
650 4 $a Engineering, Materials Science. $3 1017759
690 $a 0491
690 $a 0794
710 2 $a University of Illinois at Urbana-Champaign. $3 626646
773 0 $t Dissertation Abstracts International $g 69-02B.
790 $a 0090
790 1 0 $a Lewis, Jennifer A., $e advisor
791 $a Ph.D.
792 $a 2007
856 4 0 $u http://pqdd.sinica.edu.tw/twdaoapp/servlet/advanced?query=3301261