Scientists from the CSIR-Central Salt and Marine Chemicals Research Institute (CSMCRI), Indian Institute of Technology Gandhinagar, the Nanyang Technological University, Singapore, and the S N Bose National Centre for Basic Sciences have collaborated to develop a new class of highly precise filtration membranes. The research, published in the Journal of the American Chemical Society, could significantly reduce energy consumption and enable large-scale water reuse in industry.
Everyday industrial processes, like purifying medicines, cleaning textile dyes, and processing food, rely on “separations.” Currently, these processes are incredibly energy-hungry, accounting for nearly 40% to 50% of all global industrial energy use. Most factories still use old-fashioned methods like distillation and evaporation to separate ingredients, which are expensive and leave a heavy carbon footprint. Although membrane-based technologies are considered cleaner, most polymer membranes currently used in industry have irregularly sized pores that tend to degrade over time, limiting their effectiveness. Thus, they lack the precision and long-term stability needed for demanding industrial applications.
“To address these limitations, we engineered a new class of ultra-selective, crystalline membranes called “POMbranes”, which contain pores that are about one nanometre wide, thousands of times thinner than a human hair,” said Dr Shilpi Kushwaha, Senior Scientist at CSMCRI. This precise pore size results from an intricate molecular design that mimics the action of biological gatekeepers like aquaporins, which use pores of precisely the right size to filter molecules. The team utilised polyoxometalate (POM) clusters, which feature a permanent, naturally occurring hole exactly 1 nanometer wide. According to Ms Priyanka Dobariya, a CSMCRI research scholar and co-first author of the article, “These POMs are tiny, crown-shaped metal clusters that have a permanent, perfect hole in their centre that does not change or lose shape, which is the biggest hurdle with traditional plastic filters.”
To arrange billions of such rings into a continuous, defect-free sheet suitable for use as a membrane, the research team attached flexible chemical chains to the clusters. When placed on water, the clusters naturally spread out and align, forming an ultrathin film over large areas. By adjusting the length of the attached chains, the team could control how tightly the clusters packed together. “This forced molecules to cross the membrane through the only open path, the one-nanometre holes built into each cluster, allowing the membrane to act like a high-tech sieve,” added Dr Raghavan Ranganathan, Associate Professor at IITGN’s Department of Materials Engineering. He and Mr Vinay Thakur, a PhD scholar at IITGN and the co-first author of the article, performed molecular-level simulations that helped explain how the membranes work.
The research team has tested the membrane to distinguish between molecules that differ by just 100-200 Daltons. Such precision is extremely difficult to achieve with conventional polymer membranes. According to Dr Ketan Patel, Principal Scientist at CSMCRI, this level of control opens new possibilities for sustainable manufacturing. “Our membranes show almost ten times better separation performance compared to existing technologies, while remaining flexible, stable, and scalable,” he said. “Additionally, these membranes are flexible, stable across different acidity levels (pH ranges), and can be manufactured in large sheets. This combination is essential if the membranes are to be adopted widely in industry.”
The technology is highly relevant to India’s textile and pharmaceutical sectors, both critical pillars of the economy. The textile and apparel sector contributes over 2.3% of GDP. It accounts for around 13% of industrial production, with the domestic market valued at USD 160-225 billion and projected to grow to USD 250-350 billion by 2030. However, textile dyeing and finishing generate large volumes of polluted wastewater, making dye removal and water recycling persistent challenges. The new membranes could selectively remove dye molecules while allowing water to be reused, reducing freshwater consumption and chemical discharge. This is particularly significant as India’s wastewater treatment market is expected to grow rapidly in the coming years.
For the pharmaceutical sector, where precise separations are essential for drug purity and cost-effective manufacturing, the technology could offer significant benefits. “Processes like drug purification and solvent recovery are both energy-intensive and quality-sensitive,” noted Mr Vinay Thakur. “Highly selective membranes such as these can lower energy use while maintaining the stringent standards required in pharmaceutical production.”
The versatility of the engineered POMbranes makes them an efficient platform technology. Their tunable structure, high selectivity, and stability under harsh chemical conditions ensure their suitability for a wide range of separation challenges, from wastewater treatment to advanced chemical processing. As industries seek solutions that balance efficiency, durability, and sustainability, molecularly engineered membranes could form the backbone of next-generation manufacturing technologies. By drawing on a core principle from biology—precise control at the molecular scale—and translating it into a scalable materials system, the research shows how nature-inspired design can address real industrial needs.
Complete list of authors:
Corresponding Authors
- Dr Ketan Patel − CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar
- Dr Shilpi Kushwaha − CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar
- Prof Raghavan Ranganathan − Materials Engineering, Indian Institute of Technology Gandhinagar
- Prof Prashant Kumar − School of Materials Science & Engineering, Nanyang Technological University, Singapore
Authors
- Priyanka Dobariya − CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar
- Vinay Thakur − Materials Engineering, Indian Institute of Technology Gandhinagar
- Amrutha A − CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar
- Karan Marvaniya − CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar
- Ashish Maurya − CSIR-Central Salt and Marine Chemicals Research Institute, Bhavnagar
- Pradip Pachfule − S N Bose National Centre for Basic Sciences, Kolkata