Experimental Study of Interfacial Fracture Toughness in a SiN_x/PMMA Barrier Film

Abstract

Organic/inorganic multilayer barrier films play an important role in the semihermetic packaging of organic electronic devices. With the rise in use of flexible organic electronics, there exists the potential for mechanical failure due to the loss of adhesion/cohesion when exposed to harsh environmental operating conditions. Although barrier performance has been the predominant metric for evaluating these encapsulation films, interfacial adhesion between the organic/inorganic barrier films and factors that influence their mechanical strength and reliability has received little attention. In this work, we present the interfacial fracture toughness of a model organic/inorganic multilayer barrier (SiN(x)-PMMA). Data from four point bending (FPB) tests showed that adhesive failure occurred between the SiN(x) and PMMA, and that the adhesion increased from 4.8 to 10 J/m(2) by using a variety of chemical treatments to vary the surface energy at the interface. Moreover, the adhesion strength increased to 28 J/m(2) by creating strong covalent bonds at the interface. Overall, three factors were found to have the greatest impact on the interfacial fracture toughness which were (a) increasing the polar component of the surface energy, (b) creating strong covalent bonds at the organic/inorganic interface, and (c) by increasing the plastic zone size at the crack tip by increasing the thickness of the PMMA layer.

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

“…Owing to their excellent material properties, it expected that they will be used widely as fillers for nanocomposites, stabilizers for Pickering emulsions, , and scaffolds for cell culture. , In nanomaterials with high SSAs, the interfacial interactions between materials are critical for adhesion, detachment, and interfacial stability. Examples include the responses of cells to scaffold materials , and the interfacial fracture of nanocomposites. , In addition to the studies mentioned above, adsorption onto the surfaces of CNFs has been an important feature of numerous other studies, including those on the binding of enzymes, , and on the interfacial concentration of reagents at the surfaces of CNFs acting as catalysts . However, the adhesion between CNFs and other substances is poorly understood owing to the nano-scale widths of the fibers.…”

“…Examples include the responses of cells to scaffold materials 11,12 and the interfacial fracture of nanocomposites. 13,14 In addition to the studies mentioned above, adsorption onto the surfaces of CNFs has been an important feature of numerous other studies, including those on the binding of enzymes, 15,16 and on the interfacial concentration of reagents at the surfaces of CNFs acting as catalysts. 17 However, the adhesion between CNFs and other substances is poorly understood owing to the nano-scale widths of the fibers.…”

Manipulation of a Single Polymer Chain: From the Nanomechanical Properties to Dynamic Structure Evolution

“…However, one single coupling site especially for noncovalent coupling cannot provide sufficient strength in covalent mechanochemistry and condensed state study. , Plenty of surface treatment methods was established to achieve a higher coupling strength, e.g., creating an anhydrous microenvironment , or multisite coupling (Figure ). , As a typical example of creating multisite coupling, the hydroxyl and carboxyl groups were introduced into polyethylene (PE) and polypropylene (PP) by photocatalytic oxidation and graft polymerization, − respectively. The multisite adsorption of polar groups can significantly improve the coupling strength of nonpolar chains to the AFM tip.…”

Single-Cycle Atomic Layer Deposition on Bulk Wood Lumber for Managing Moisture Content, Mold Growth, and Thermal Conductivity

“…Because gases can rapidly permeate complex geometries, these approaches often provide conformal modification of even intricate polymeric structures like photoresists, fabrics, − membranes, and foams . The chemistry between common ALD precursors and common synthetic polymers − (such as poly­(amides), poly­(esters), and poly­(methacrylates)) has been intently studied and repeatedly shown to create novel material properties. Similarly, ALD on natural polymers, such as cellulose, has been broadly examined and shown to improve the strength of cellulosic fibers, enable wearable sensors, and make cotton a selective sorbent for oil spill remediation .…”