Characterization of Ultra and Nanofiltration Commercial Filters by Liquid-liquid Displacement Porosimetry

Table of Contents

1. OVERVIEW OF MEMBRANE SCIENCE AND TECHNOLOGY

1.1 INTRODUCTION

1.2 MEMBRANE MARKET

1.3 FUNDAMENTALS OF MEMBRANES

1.3.1 Definition and Classification

1.3.2 Membrane Module Design

1.3.3 Membrane Material

1.4 MEMBRANE PROCESSES

1.4.1 Pressure Driven Membrane Processes

1.4.2 Concentration Gradient Driven Processes

1.4.3 Electrical Potential Driven Membrane Processes

1.4.4 Temperature Gradient Driven Membrane Processes

1.5 CHARACTERIZATION OF MEMBRANES

1.5.1 Characterization Methods

1.5.2 Methods of Liquid Penetration

1.5.2.1 Fundamentals

1.5.2.2 Bubble Point Method

1.5.2.3 Fluid Displacement

-Air Liquid Displacement

-Liquid-Liquid Displacement

1.6 CONCLUSIONS

1.7 REFERENCES

2. DEVELOPMENT AND OPTIMIZATION OF A LIQUID-LIQUID DISPLACEMENT POROMETER DEVICE

2.1 HISTORICAL

2.2 LLDP ANALYSIS FUNDAMENTALS

2.2.1 Grabar-Nikitine Algorithm

2.3 AUTOMATED LLDP POROSIMETER

2.3.1 LLDP Setup

2.3.2 Porosimetric Liquids Preparation

2.3.3 LLDP Analysis

2.3.4 Data Analysis and Treatment

2.4 CONCLUSIONS

2.5 REFERENCES

3. Paper one Characterization of UF membranes by liquid–liquid displacement porosimetry

4. Paper two Characterisation of polymeric UF membranes by liquid–liquid displacement porosimetry

5. Paper three Liquid-liquid displacement porosimetry for the characterization of virus retentive membranes.

6. Paper four Liquid-liquid displacement porometry to estimate the molecular weight cut-off of ultrafiltration membranes

7. CONCLUSIONES / CONCLUSIONS

Research Objectives & Topics

The primary objective of this doctoral thesis is to enhance the Liquid-Liquid Displacement Porosimetry (LLDP) technique and optimize its application for analyzing commercial porous filters. The work focuses on automating existing setups, verifying optimal working conditions, and establishing theoretical correlations between membrane structure and industrial performance data.

• Automation and optimization of LLDP equipment and software.
• Characterization of Ultrafiltration (UF) and Nanofiltration (NF) membranes.
• Correlation of structural pore information with functional performance indicators like Molecular Weight Cut-Off (MWCO).
• Development of standardized protocols for reliable membrane testing.
• Application to virus retentive membranes and assessment of filtration performance.

Excerpt from the Book

Summary of Chapters

1. OVERVIEW OF MEMBRANE SCIENCE AND TECHNOLOGY: Provides a comprehensive review of membrane science, markets, material classification, and existing characterization techniques used in the industry.

2. DEVELOPMENT AND OPTIMIZATION OF A LIQUID-LIQUID DISPLACEMENT POROMETER DEVICE: Details the engineering improvements, algorithm development, and automated setup created to enhance the accuracy and reproducibility of LLDP measurements.

3. Paper one Characterization of UF membranes by liquid–liquid displacement porosimetry: Presents the initial validation of the LLDP technique using various polysulfone and polycarbonate membranes to determine pore size distributions.

4. Paper two Characterisation of polymeric UF membranes by liquid–liquid displacement porosimetry: Extends the characterization to different series of commercial polymeric membranes, comparing results with other methods.

5. Paper three Liquid-liquid displacement porosimetry for the characterization of virus retentive membranes: Investigates the specific application of LLDP to characterize virus retentive membranes and correlates findings with phage retention data.

6. Paper four Liquid-liquid displacement porometry to estimate the molecular weight cut-off of ultrafiltration membranes: Focuses on establishing a methodology to estimate MWCO values for UF membranes using structural data obtained via LLDP.

7. CONCLUSIONES / CONCLUSIONS: Summarizes the key achievements of the research, including the successful automation of the device and the establishment of LLDP as a reliable tool for membrane structural and functional characterization.

Keywords

Ultrafiltration, Nanofiltration, Membrane Characterization, Liquid-Liquid Displacement Porosimetry, LLDP, Pore Size Distribution, MWCO, Molecular Weight Cut-Off, Porosity, Virus Retentive Membranes, Polymeric Membranes, Membrane Modules, Permeability, Filtration, Membrane Science.

Frequently Asked Questions

What is the core focus of this doctoral thesis?

The thesis focuses on improving and automating the Liquid-Liquid Displacement Porosimetry (LLDP) technique to provide a reliable, accurate, and standardized method for characterizing the structural properties of commercial ultrafiltration and nanofiltration membranes.

What are the primary themes covered in the research?

Key themes include membrane material science, the physics of fluid displacement in porous media, the automation of measurement hardware and data analysis software, and the correlation of structural pore data with operational performance parameters.

What is the main research goal?

The primary goal is to establish LLDP as a standard, non-destructive, and efficient characterization technique that can estimate membrane performance metrics like Molecular Weight Cut-Off (MWCO) and virus retention capability without needing time-consuming retention experiments.

Which scientific methods are utilized?

The study employs LLDP as the central characterization technique, complemented by scanning electron microscopy (SEM) for imaging, and various mathematical models, specifically the Cantor and Hagen-Poiseuille equations, to analyze pore size distributions and permeability.

What does the main body of the work cover?

It includes a comprehensive literature review of membrane science, a detailed technical description of the automated LLDP setup and the Grabar-Nikitine algorithm, and a series of experimental studies involving various commercial membranes to validate the technique.

Which keywords best describe this work?

Essential terms include Ultrafiltration, LLDP, Pore Size Distribution, Membrane Characterization, MWCO, Virus Retentive Membranes, and Fluid Displacement.

How does LLDP compare to gas-based porometry?

Unlike gas-liquid porometry, which requires extremely high pressures that can damage small pores in ultrafiltration membranes, LLDP uses a liquid-liquid interface, allowing for accurate characterization at much lower, non-destructive pressures.

Can LLDP predict the Molecular Weight Cut-Off (MWCO)?

Yes, one of the significant contributions of this thesis is the development of a protocol that correlates structural pore size distributions derived from LLDP data with operational MWCO values, offering a much faster alternative to traditional solute retention tests.