Rheology and Clogging Study of Filamentous Suspensions: Bridging Microscopic Dynamics and Macroscopic Behaviors Ravisara Wattana

Format:

Book

Thesis/Dissertation

Author/Creator:

Wattana, Ravisara, author.

Contributor:

University of Pennsylvania. Materials Science and Engineering., degree granting institution.

Language:

English

Subjects (All):

0494.

0495.

0565.

0794.

Local Subjects:

0494.

0495.

0565.

0794.

Physical Description:

1 electronic resource (251 pages)

Contained In:

Dissertations Abstracts International 87-07B

Place of Publication:

Ann Arbor : ProQuest Dissertations and Theses, 2025

Language Note:

English

Summary:

Suspensions of filamentous materials, or filamentous suspensions, represent a unique class of complex fluids in which the interplay between particle anisotropy and filament interactions - both intra- and inter-filament associations -gives rise to rich and tunable rheological behaviors. Such suspensions are ubiquitous across natural and engineered systems, with their applications ranging from the locomotion of microorganisms and drag reduction in turbulent flows to fiber processing in papermaking and the development of functional nanomaterials. Their filamentous or fibrillar nature, marked by a high-aspect-ratio particle structure and finite mechanical flexibility, enables not only the formation of entangled networks in which mechanics and dynamics depend strongly on dimension, concentration, and surface chemistry, but also introduces greater complexity to material responses and flow phenomena. Despite their widespread utilization as colloidal materials, understanding how filamentous suspensions are affected by interactions among molecular species and filaments under varying conditions (pH, temperature, ionic strength, et cetera), as well as mechanisms governing clogging, remains limited. Such understanding is crucial for tailoring their properties and performance to meet the needs of specific applications, such as rheology modification of complex fluids. To address these knowledge gaps, two complementary studies-rheology and clogging-are performed independently at the microscopic and macroscopic scales, respectively, to elucidate how the filamentous structure and associated physical properties manifest across multiple length scales. First, we systematically investigate the rheology of cellulose nanofibril (CNF) suspensions in the presence of salts and polymers to probe microscopic mechanisms arising from fibril-fibril, fibril-salt, and fibril-polymer interactions. Our studies reveal how ion-colloid and polymer-colloid interactions dictate the formation, structure, and dynamic response of CNF networks, providing a framework for the design of enhanced CNF-containing complex fluid formulations. Secondly, we examine the clogging behavior of suspensions of threadlike colloids to uncover the macroscopic mechanisms underlying collective dynamics in these granular systems. Analysis of clogging probability and flow conditions provides insight into the transition between flow and jammed (clogged) states. Hence, these investigations establish a deeper understanding of how anisotropic filamentous geometry and its corresponding interactions govern complex rheological and flow-arrest behaviors, thereby guiding the design of advanced materials and the optimization of processing for filament-based materials

Notes:

Advisors: Osuji, Chinedum O. Committee members: Bidstrup-Allen, Sue Ann; Composto, Russell J.; Winey, Karen I.

Source: Dissertations Abstracts International, Volume: 87-07, Section: B.

Ph.D. University of Pennsylvania 2025

Vendor supplied data

Local Notes:

School code: 0175

ISBN:

9798276006543

Access Restriction:

Restricted for use by site license