Carbon-doped titania nanofiltration membrane with precisely tuned molecular-sized pores

Overview

This technology is an ultrathin carbon-doped titania nanofiltration membrane with precisely controlled, molecular-sized pores. Formed via a fast interfacial reaction between organic precursors (such as ethylene glycol) and metal precursors (such as TiCl4), the resulting hybrid nanofilm is initially impermeable but can be converted into a porous nanofiltration membrane through controlled calcination. By adjusting the calcination gas environment (air or nitrogen) or the water content in the precursor mixture, the molecular weight cut-off (MWCO) of the membrane can be precisely tuned between 200 and 1,200 Daltons. This level of pore-size precision enables highly selective separation of target molecules while maintaining exceptional flux—approximately two orders of magnitude higher than commercial nanofiltration membranes—due to the membrane's ultrathin (~30 nm) architecture.

Potential applications include selective extraction of flavor and aroma compounds from food and beverage products, pharmaceutical purification, and other molecular-level separation processes requiring both high selectivity and high throughput.

Technical specifications

• Membrane thickness: Ultrathin, approximately 30 nm, enabling significantly higher flux than conventional nanofiltration membranes.
• Pore-size control: MWCO precisely tunable between 200 and 1,200 Da by adjusting calcination conditions (air vs. nitrogen atmosphere) or by varying the water content in the ethylene glycol precursor mixture.
• Fabrication method: Interfacial reaction between ethylene glycol (or ethylene glycol/water mixtures) and TiCl4, followed by calcination to remove carbon compounds and open pores.
• Material composition: Carbon-doped titania, combining the chemical stability of titanium oxide with carbon-based structural tuning.
• Performance: Demonstrated impermeability to gases and water under pressure drops greater than 10 bar prior to calcination, confirming membrane integrity.
• Flux advantage: Approximately two orders of magnitude higher flux than commercial nanofiltration membranes.
• Separation selectivity: Molecular-level discrimination based on precisely controlled pore dimensions.

Technology readiness level

The membrane fabrication process has been validated in laboratory settings, with demonstrated control over pore size and confirmed performance advantages over commercial alternatives. Current work includes forward osmosis testing using electrolyte draw solutions to selectively extract aldehydes, lactones, benzothiazoles, and alcohols from coconut water, with ongoing evaluation of optimal pore sizes for both selectivity and flux. Future validation will include long-term operational testing to assess commercial viability. The technology is at an early-to-mid stage of development, with proof-of-concept demonstrated and application-specific optimization underway.