Scrutinizing the Nanostructural and Nanomechanical Features of Regenerated Cellulose Ultrafiltration Membranes

Luciano Paulino Silva

doi:10.6000/1929-6037.2015.04.01.4

Abstract

Ultrafiltration (UF) membranes have been widely used for many separation processes in which high performance is required. Commercial regenerated cellulose UF membranes with variable molecular weight cut-offs were characterized by high performance atomic force microscopy (AFM) using the novel quantitative nanomechanical mapping mode and the versatility of its signal channels towards nanoscale features elucidation of the materials surface. In addition, Raman spectroscopy was applied in order to investigate some possible chemical behavior changes associated with the UF membranes’ cut-offs. Overall, the results showed that the proposed AFM method was reliable to gain qualitative and quantitative data at unprecedented nanoscale resolution and such information can be used to distinguish UF membranes according to their specific molecular weight cut-offs and properties even on situations in which the molecular behavior were not influenced by the UF membrane’ cut-off. This approach can be useful on quality control procedures of researchers and manufacturers producing or modifying these polymeric materials.

Highlights

Ultrafiltration (UF) is a technique commonly applied for the pressure-driven membrane separation of structures up to 100 nm in diameter [1]
In a recent report of our research group on polymeric porous membranes [5], we observed the nanoscale behaviors of microfiltration membranes (0.45 m porosity filters) formed by different polymers and evaluated by atomic force microscopy (AFM), single-point force spectroscopy, and chemical investigation approaches
The present study aims to investigate the use of high performance AFM operated under quantitative nanomechanical mapping mode to investigate the topographical and mechanical surface of regenerated cellulose UF membranes with molecular cut-offs ranging from 3 to 100 kDa

Summary

Introduction

Ultrafiltration (UF) is a technique commonly applied for the pressure-driven membrane separation of structures up to 100 nm in diameter [1]. The present study aims to investigate the use of high performance AFM operated under quantitative nanomechanical mapping mode to investigate the topographical and mechanical surface of regenerated cellulose UF membranes with molecular cut-offs ranging from 3 to 100 kDa. Raman spectroscopy was used to study the chemical behavior of the UF membranes.

Results

Conclusion