(334h) Rheological Characterization of Cellulose Nanomaterials for Quality Control and Processing

Rheology is the study of flow and deformation of the matter. It is a useful tool to understand the structure-property relationships of materials at various conditions. Fundamental theories and empirical equations are established to connect the rheological properties to the many material properties, which guide formulation screening and process optimization. My research interest lies in the material characterization together with model building and validation to address the challenges in material design and manufacturing.

Research Background

In my PhD study, I use my expertise in rheology to characterize various materials in many applications aiming to screen formulations and optimize processes. My thesis work focuses on rheological characterization of cellulose nanomaterials. [1] To expand the nanomaterials production capacity to industrially relevant scale and to ensure consistent production of the cellulose nanomaterial, one of the most urgent issues to be addressed is the lack of standardized, rapid and reliable characterization method for quality control during the manufacturing process. My research shows the potential of rheology as a quality control tool for these nanomaterials. Preparation and test protocols are first established to obtain reliable viscosity data at manufacturing relevant conditions. Next, a rheological model is developed, which can accurately capture the viscosity across shear rates and concentrations. The model can be used to estimate the concentration of an uncharacterized sample which is much faster than the current method to determine the concentration by drying in oven. Moreover, a flow index is developed to condense large sets of data into one single value, working as a “fingerprint” of the material. This flow index can be used to identify materials at different processing conditions, including different morphologies or surface charges. Finally, a processing method is developed to concentrate cellulose nanomaterials and obtain high loadings of well-dispersed nanomaterials in polymer composite gels. For collaborative projects, I use rheology to screen formulations for solution-based 3D printing [2], composites for fiber spinning, hydrogel fabrication and food formulations for swallowing difficulties study.

[1] Liao, J., Pham, K. A., & Breedveld, V. (2020). Rheological characterization and modeling of cellulose nanocrystal and TEMPO-oxidized cellulose nanofibril suspensions. Cellulose, 1-17.

[2] Zhang, F., Ma, Y., Liao, J., Breedveld, V., & Lively, R. P. (2018). Solution‐Based 3D Printing of Polymers of Intrinsic Microporosity. Macromolecular rapid communications, 39(13), 1800274.