Evaluation of Surface Free Energy Inducing Interfacial Adhesion of Amphiphilic Cellulose Nanofibrils

Abstract

Cellulose nanofibrils (CNFs) have been studied extensively over the past decade. Their applications, e.g., as fillers for nanocomposites, stabilizers for Pickering emulsions, and scaffolds for cell culture, are mostly dictated by interfacial adhesion. In general, the individual surface free energy values of the constituents of a material correlate with its adsorption and desorption behaviors.In the present study, we estimated the surface free energy values of thin films composed of CNFs using traditional contact angle methods based on the Wenzel equation and van Oss−Chaudhury− Good theory. The accuracy and utility of the estimated surface free energy values were verified by close matching between the obtained adhesion energy values and the actual interfacial adsorption behaviors of the CNFs. Therefore, the evaluated surface energy values are expected to be a feasible tool for designing of interfacial interactions between CNF surfaces and other materials.

Impact-Resistant Nanocomposite Plastics Embedding “Plant Cell Walls”-Mimicked Frameworks with Ultratrace Amounts of Amphiphilic Cellulose Nanofibrils

“…This loading corresponded to the formation of an ACC–CNF monolayer on the microspheres (Figure S2c). In our previous papers, , we confirmed the exclusive feature of the ACC–CNFs of favorably adsorbing to various conventional plastics. In Supporting Information, Table S1, the adsorption of ACC–CNFs from different raw materials and NFC (NFC prepared by microfluidizer) as a regular CNF is listed.…”

“…Note that after drying and washing with water, ACC–CNFs are still attached to the plastics, not removed in dried states, and previously, the formation of such a sufficient interaction in dried states had been proved by thermodynamic analyses . Recently, we have also estimated surface free energy parameters of CNFs, indicating that the parameter values of ACC–CNFs are significantly different from those of other CNFs …”

“…35 Recently, we have also estimated surface free energy parameters of CNFs, indicating that the parameter values of ACC−CNFs are significantly different from those of other CNFs. 40 During extrusion, the melt flow rate is a critical factor that determines the efficiency of the injection molding process in industrial applications. Hence, the melt flow rates determined for the neat iPP, coated iPP, and prepressed coated iPP are summarized in Table 1.…”