Colloidal-rods for examining polymer dynamics in complex flows

2023 Fiscal Year Final Research Report

• Project/Area Number: 22K14738
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 35020:Polymer materials-related
• Research Institution: Okinawa Institute of Science and Technology Graduate University
• Principal Investigator: Calabrese Vincenzo 沖縄科学技術大学院大学, マイクロ・バイオ・ナノ流体ユニット, ポストドクトラルスカラー (40895413)
• Project Period (FY): 2022-04-01 – 2024-03-31
• Keywords: polymers / colloids / rheology / microfluidics

Outline of Final Research Achievements

During these two years of the project, the candidate advanced the fundamental understanding of the dynamics of colloidal-rods alignment in polymeric solutions. The candidate has shown that the onset of flow-induced alignment of relatively small colloidal-rods is coupled with the relaxation dynamics of the surrounding polymers. On the contrary, the onset of flow-induced alignment of relatively large colloidal-rods is govern by the bulk viscosity of the polymer solution. This understanding has important conclusions for the primary purpose of the proposed research project. Specifically, this understanding can lead to the development of a technique based on the alignment of colloidal rods, referred to as colloidal-rods alignment micro-rheology (CRAM), to provide quantitative and spatially resolved structural properties of polymeric fluids in complex flows.

Free Research Field

polymer

Academic Significance and Societal Importance of the Research Achievements

The results obtained with this project indicate that colloidal rod alignment in polymer solutions can be predicted on the basis of the critical shear rate at which polymer coils are deformed by the flow, aiding the synthesis and design of anisotropic materials.