In the field of hollow fiber ultrafiltration membranes, polyvinylidene fluoride (PVDF) and polyethersulfone (PES) are two of the most widely applied polymer materials. This comparative analysis of PVDF vs PES membranes, evaluating their performance in various filtration environments and industrial applications.
1. Material Properties and Chemical Stability
| Property | PVDF (Polyvinylidene Fluoride) | PES (Polyethersulfone) |
| Oxidation Resistance | Tolerates 5000 ppm NaClO + 4% NaOH | Up to 2000 ppm·h ClO₂ |
| PH Resistance Range | 1-14 | 1-14 |
| Chlorine Resistance | 5000 ppm·h | 250 ppm |
| Temperature Limit | ≤45°C | ≤85°C |
2. Mechanical Properties and Structural Design
| Parameter | PVDF (Thermally Induced Phase Separation) | PES (Non-Solvent Induced Phase Separation) |
| Breaking Strength | ≥10N (single fiber) | ≥6N (single fiber) |
| Compaction Resistance | 3D uniform network structure | Gradient sponge structure |
| Flux Stability | Excellent fouling resistance (contact angle drops to 0° in 30s, hydrophilic modification) | High water permeability (steady flux 80-150 [email protected]) |
3. Separation Performance and Operational Adaptability
| Parameter | PVDF Preferred Applications | PES Preferred Applications |
| Pore Size Range | 0.03-0.1µm | 20-50nm |
| Typical Flux | 2000 L/(m²·h·bar) (TIPS process) | 650-1500 [email protected] (internal pressure membrane) |
| Fouling Resistance Mechanism | High porosity (surface porosity >74.1%), efficient air scrubbing | Positive charge modification (anti-organic adsorption) |
| Water Quality Suitability | High SS (300 mg/L), high turbidity (400 NTU) | Low SS (<50 mg/L) |
4. Engineering Economics Comparison
| Dimension | PVDF | PES |
| Unit Membrane Area Cost | High (material cost + thermal process) | Medium (optimized wet process) |
| Cleaning Frequency | Low (CEB cycle >72h, tolerates intense cleaning) | High (frequent CIP for biofouling) |
| Service Life | ≥8 years (FiltMem seawater desalination case) | 5-6 years (municipal drinking water) |
5. PVDF vs PES Application Scenarios
PVDF Preferred Scenarios:
- Industrial wastewater: Refinery oily wastewater
- Seawater desalination pretreatment: SDI<3
- MBR field: Medical wastewater treatment (sludge concentration >12 g/L)
PES Preferred Scenarios:
- Drinking water virus removal: 6-log bacteria/4-log virus removal
- Biopharmaceutical separation: 30 kDa PES membrane for antibody purification
- Low-pressure energy-saving systems: Full-flow filtration energy consumption <0.2 kWh/m³
PVDF is suitable for complex industrial scenarios due to its high thermodynamic stability and enhanced cleaning capabilities, while PES is the preferred choice for high-purity water treatment due to its precise pore size control and low-pressure high flux. Selection should consider water quality parameters, operating costs, and process compatibility.
