Characterization of polyamide thin films by atomic force microscopy

• Published in: Polymer (Guilford) Vol. 308; p. 127350
• Main Authors: McIntee, Olivia M., Sreedhar, Nurshaun, Welch, Brian C., Bright, Victor M., Roy, Abhishek, Paul, Mou, Greenberg, Alan R.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 20.08.2024
• Subjects: Atomic force microscopy; Elastic modulus; Interfacial polymerization; Molecular layer deposition; Polyamide thin films; Surface roughness; Interfacial polymerization; Atomic force microscopy; Elastic modulus; Surface roughness; Polyamide thin films; Molecular layer deposition
• ISSN: 0032-3861
• DOI: 10.1016/j.polymer.2024.127350

This study directly compares the mechanical behavior of novel molecular layer deposition (MLD) and analogous interfacial polymerization (IP) polyamide thin films in environments relevant to reverse osmosis (RO) membrane operation. The elastic modulus of the films was determined using atomic force microscopy (AFM) in dry, hydrated, and chlorinated states. Surface roughness characteristics were also obtained given their potential influence on AFM modulus measurements. The much smoother MLD films demonstrated a statistically higher modulus in all states as compared to their IP counterparts. The MLD films maintained a modulus ∼3X and ∼5X greater than that of IP films after hydration and chlorination, respectively. Such differences in behavior may be due to the higher density and correspondingly lower void content of the MLD films. Results from this study provide a rationale for future development of MLD for fabrication of polyamide films for incorporation in RO membranes. [Display omitted] •Novel polyamide thin films were fabricated by molecular layer deposition (MLD).•Physical and mechanical characteristics of MLD films were compared to interfacially polymerized (IP) films of similar thickness.•Elastic modulus and RMS roughness were measured using atomic force microscopy.•Modulus was measured in dry, hydrated, and chlorinated conditions.•MLD films were much smoother and had a statistically greater modulus as compared to IP films in all conditions.