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dc.contributor.advisor Biswal, Sibani Lisa
dc.creatorLi, Dichuan
dc.date.accessioned 2013-03-08T00:35:52Z
dc.date.available 2013-03-08T00:35:52Z
dc.date.issued 2011
dc.identifier.urihttps://hdl.handle.net/1911/70316
dc.description.abstract Colloidal particles are ideal models for studying the behavior of atomic and molecular systems. They resemble their atomic and molecular analogues in that their dynamics are driven by thermal energy and their equilibrium properties are controlled by inter-particle interactions. Based on this analogy, it is reasonable to construct colloidal chains, where each particle represents a repeat unit, as models for polymers. The advantages of this system over molecular systems are its controllable rigidity, contour length and diameter, as well as the convenience to capture its instantaneous shape and position via video microscopy, which are not trivial to realize in molecular systems. By utilizing the dipolar properties of magnetic colloids, a number of groups have assembled semiflexible and rigid colloidal chains by cross-linking magnetic beads under a magnetic field using polymer linkers. Recently, efforts in constructing colloidal chains led even to anisotropic magnetic colloidal chains that mimic the detailed atomic arrangements of polymers. These properties make colloidal chains possible candidates for the classic bead-spring or bead-rod model systems for semiflexible and rigid polymers. In my thesis, I present a method for generating linear colloidal chain structures by linking surface functionalized paramagnetic particles using DNA. First, I investigate the force interactions between individual magnetic particles under different conditions to optimize the resulting chain stability. A systematic study the bending and rotational diffusion dynamics of the chains and their relationship with the DNA linking chemistry is presented. I then demonstrate their use as a ideal model system to study polymer dynamics In addition, a technique to measure short-range repulsive surface forces between these colloids with high precision was developed. Building on these repulsive force studies, a colloidal system to study 2-D phase transitions was created. This thesis provides insights into understanding and engineering the directed-assembly of magnetic colloids with specific surface interactions, as well as using the assemblies as model systems to study molecular level phenomena.
dc.format.extent 212 p.
dc.format.mimetype application/pdf
dc.language.iso eng
dc.subjectApplied sciences
Pure sciences
Biological sciences
Brownian motion
Surface forces
Colloids
Chemical engineering
Molecular physics
Biophysics
dc.title Paramagnetic particle assemblies as colloidal models for atomic and molecular systems
dc.identifier.digital LiDichuan
dc.type.genre Thesis
dc.type.material Text
thesis.degree.department Chemical and Biomolecular Engineering
thesis.degree.discipline Engineering
thesis.degree.grantor Rice University
thesis.degree.level Doctoral
thesis.degree.name Doctor of Philosophy
dc.identifier.citation Li, Dichuan. "Paramagnetic particle assemblies as colloidal models for atomic and molecular systems." (2011) Diss., Rice University. https://hdl.handle.net/1911/70316.


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