Salinity-proof epoxy coating for marine installations

by Hansraj Agrawal | Dec 1, 2025 | Science

Researchers at the Indian Institute of Technology, Guwahati, have developed a corrosion-resistant epoxy coating designed to protect steel structures exposed to seawater and high-salinity environments.

The work, published in Advanced Engineering Materials, was carried out by Prof Chandan Das of the Department of Chemical Engineering, and research scholar Dr Anil Kumar.

Corrosion weakens metal and shortens the life of critical infrastructure — offshore platforms, coastal bridges, ports, and marine pipelines — causing major industrial accidents, including the 1984 Bhopal gas tragedy.

Conventional barrier coatings, though widely used, eventually develop microscopic defects that allow moisture and salts to penetrate and attack the underlying metal. To strengthen these coatings, researchers worldwide have experimented with incorporating nanomaterials — ultra-small particles that enhance mechanical strength and protective performance. However, no previous study has integrated reduced graphene oxide, zinc oxide, and polyaniline into a single epoxy coating for marine corrosion protection.

The IIT-Guwahati team has combined all three. They created a novel nanocomposite by attaching zinc oxide nanorods to reduced graphene oxide and wrapping the structure with polyaniline. This composite was then blended into an epoxy coating and tested through multiple characterisation techniques.

The resulting coating outperformed standard epoxy, forming a denser and more uniform barrier, exhibiting stronger adhesion to steel, and slowing the movement of corrosive elements far more effectively. These advantages make it well suited for steel structures with saltwater exposure.

Nano tetrapods that help polymers flow smoothly

A team of researchers from IIT-Bombay, IIT-Madras, and IIT-Kanpur has found that adding tiny, four-armed nanoparticles can help thick polymers flow more smoothly. These nanoparticles, shaped somewhat like miniature versions of the concrete tetrapods used along coastlines, were mixed with the commonly studied polymer polystyrene. Polymers with long, heavy chains often resist flow, but the unusual geometry of these particles appears to ease that resistance.

The idea was tested using cadmium–selenium tetrapod nanoparticles, which were blended into polystyrene and compared with spherical and rod-shaped particles. Only the tetrapod form reduced viscosity; the other shapes actually made the material thicker. The researchers also confirmed that the polymer’s strength and heat resistance remained unchanged after adding the tetrapods.

The work suggests that if such precisely shaped nanoparticles can be produced at scale, they could one day help lower the energy required to process polymers with high molecular weights.

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Published on December 1, 2025

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Heat from small-scale solar units could accelerate India’s net-zero transition

by Hansraj Agrawal | Nov 28, 2025 | Science

Energy from the sun currently powers most renewable resources worldwide, due to widespread availability
| Photo Credit:
jokerpro

India’s target for achieving net-zero emissions hinges wholly on large-scale adoption of renewable energy. Currently, coal accounts for more than 80 per cent of the country’s energy production, and this emits more than 2.4 billion tonnes of carbon dioxide annually.

Energy from the sun currently powers most renewable resources worldwide, due to widespread availability, but conventional solar photovoltaic (PV) units require a huge investment. PV modules also have a significant ecological impact and their effectiveness declines at high temperatures.

One alternative to PV cells is solar thermal power, where solar energy is converted into heat to generate electricity. When combined with thermal energy storage devices (TES), it offers several advantages over conventional PV systems, such as lower investment and increased reliability.

In a paper titled ‘Techno economic feasibility study of solar organic Rankine cycle in India’, submitted to the Physics and Society journal last week, the authors point out that TES devices are a sound alternative in solar power harvesting, vis-a-vis the environmental impact of solar panels.

The study — conducted by researchers from the Indian Institute of Engineering Science and Technology, Shibpur; Imperial College, London; and the Indian Institute of Technology, Kharagpur — evaluates the performance and cost-effectiveness of solar organic Rankine cycle (ORC) technology under Indian climatic conditions.

The paper notes that India aims to generate 40 per cent of its electricity from renewable sources by 2030. The country has achieved a 226 per cent increase in renewable energy installation, now accounting for about 25 per cent of total installed capacity.

‘Optimal fluid’

Solar ORC technology converts heat into electricity. Compared to traditional steam-based Rankine cycle technology, it generates heat at lower temperatures, making it suitable for low-power electricity generation (up to 100 kWe). The system uses solar energy to heat an organic fluid, which then expands to generate mechanical power and, in turn, electricity.

The study evaluated seven fluids. The findings suggest that ‘R 1233zd (E)’ is the optimal fluid, in terms of cost and environmental impact. This organic fluid belongs to the category of hydrofluoro-olefin refrigerants.

In the ORC system, heat from a solar collector is transferred via the fluid to an evaporator. The fluid is pumped to a high pressure, where it absorbs the heat in the evaporator, turning into a superheated vapour. This vapour then expands in an ‘expander’ to generate mechanical power, which drives a generator to produce electricity. Finally, the fluid cools in a condenser to repeat the cycle.

Competitive costs

The study shows that ORC systems are competitive compared with solar PV technology and their cost is significantly lower than that of biomass-based ORC systems across various power targets. For instance, the cost for a 100 kW S-ORC unit is $895-1,122 per kWh. A comparable solar PV system would cost $988 per kWh.

Developing countries, including India, would likely benefit from investing in this efficient, low-cost solar thermal option. But not all is rosy yet. There is still work to be done on the thermal solar front, too. The authors point out that there is further scope to reduce costs by optimising components such as the solar collector and expander, and improve efficiency even further.

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Published on November 28, 2025

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Breakthrough in desalination technology, using carbon ‘flowers’

by Hansraj Agrawal | Nov 17, 2025 | Science

JANUS-FACED FLOATING FILM: Schematic representation of the steps involved in the fabrication of an NCF@PH solar–thermal interfacial evaporator

A group of researchers have reported a breakthrough in desalination that could dramatically change the economics of producing freshwater from the sea and brackish water.

The innovation centres on an engineered material — an ultra-thin floating film called NCF@PH, described as “Janus-faced” because it has two distinct sides, like the Roman god. One side contains nano-carbon florets (NCF) — nano-carbon structures shaped like tiny marigold flowers — which are optimised to trap sunlight and minimise reflection. The other side is made of a special porous polymer (porosity-tuned high internal phase emulsion polymer).

Imagine a tank of seawater covered by a glass sheet. The NCF@PH film floats on the water, covering it. When sunlight strikes the system, the NCF on the sun-facing side absorbs large amounts of light.

The underside of the film — in contact with the water — acts as a scaffold for the NCF coating. The NCF heats the water, causing it to evaporate. Water vapour passes through the film into the space between the film and the glass lid, from where it is directed to a Peltier cooler for condensation.

Evaporation boost

Researchers from the departments of chemistry and mechanical engineering at IIT-Bombay collaborated with Monash University in Australia to build a prototype system called SunSpring. The core of the system is the NCF material.

Two years ago, Prof Subramaniam Chandramouli of IIT-Bombay, who is part of the SunSpring team, had synthesised these nano-carbon florets using silica “moulds”. As reported in Quantum on February 10, 2023, he demonstrated that when coated on porcelain or copper and exposed to sunlight, the material could heat up to 160 degrees C within minutes.

In a recent paper in Advanced Science, the researchers describe how the NCF is integrated onto a porosity-engineered, hydrophobic polymer to create an ultra-thin (200 micrometre), unsinkable solar-thermal evaporator. This design boosts the water evaporation rate to 4.5–6.5 kg per sqm per hour, compared with 1.29 kg in conventional systems.

As a result, SunSpring can produce 18 litres of freshwater per sqm per day — more than double the 7 litres typical of standard evaporation-based desalination systems. The combination of NCF and polymer channels the solar-thermal energy to the water for evaporation and prevents heat loss to the environment.

Tests at IIT-Bombay showed that SunSpring could convert seawater containing 35,000 ppm of salt into freshwater with less than 10 ppm of salt. According to Mohammed Aslam and Amrutha Suresh, the lead authors of the work, the device can run continuously for up to 225 hours.

Efficient condensation

A major improvement is in the way SunSpring handles condensation. In conventional solar stills, the same glass surface is used both to admit sunlight and to condense vapour. Once condensation begins, droplets form on the glass, scattering light and reducing heating — and therefore reducing efficiency.

SunSpring avoids this problem by separating the evaporation and condensation chambers. The condensation surface is a Peltier cooler, a thermoelectric device that becomes cold on one side and hot on the other when powered. “An important aspect of the SunSpring design lies in the decoupling of the sunlight-admitting surface from the water-collection surface,” the paper notes. In addition, salt accumulates only on the water-facing underside of the film, from where it can be easily washed away.

The research is supported by The Green Energy and Sustainability Hub at IIT-Bombay and Anusandhan National Research Foundatuon (ANRF).

Cost factor

Prof Chandramouli estimates that SunSpring can produce freshwater at thrice the cost of a typical RO system. However, costs will fall when the NCF@PH film is produced at an industrial scale.

The team, after two years of development work, now plans to set up a pilot plant in the Rann of Kutch, Gujarat, where groundwater salinity is extremely high and affects local health. The pilot, to be installed in a school, will provide 300 litres of pure water per day for the children.

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Published on November 17, 2025

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Tiny heater to kill tumours

by Hansraj Agrawal | Nov 17, 2025 | Science

Cancer treatments like radiation and chemotherapy are powerful because they target and destroy cancer cells that other methods cannot reach. Yet, doctors often use an additional treatment after these — called adjuvant therapy — to eliminate any remaining cancer cells. One such promising adjuvant treatment is hyperthermia therapy, which uses heat to make tumours more sensitive to radiation and chemotherapy.

In hyperthermia treatment, doctors raise the temperature of the tumour to about 40–44 degree C for up to an hour. This weakens cancer cells while leaving healthy tissue relatively unharmed. It works especially well for superficial cancers — those on or near the body’s surface, such as cancers of the breast, neck, or skin.

However, heating small, curved areas of the body — like the face or nose — poses a major challenge. Existing hyperthermia devices are too large and often fail to deliver heat evenly to small, localised tumours.

To solve this, Rahul Choudhury and Prof Kavita Arunachalam, at the Department of Engineering Design at IIT-Madras, have developed a compact hyperthermia applicator that operates at 434 MHz, a frequency used for cancer treatment. Their design features a single small antenna with an integrated water bolus — a thin, water-filled layer that helps the device conform perfectly to curved surfaces and ensures even heating without air gaps.

Tests conducted on artificial tissue models and real chicken and bovine samples showed highly efficient heating, with over 96 per cent power coupling and stable, targeted energy delivery. The device is significantly smaller than current models and offers a way to treat small, localised tumours that were previously difficult to reach.

Diamond in quantum sensor

Under the National Quantum Mission (NQM) of the Department of Science and Technology (DST), researchers at IIT-Bombay’s PQuest Group have built India’s first quantum diamond microscope (QDM) — a device that can capture magnetic fields in real time at the microscopic level. This marks a major step for the country in the field of quantum sensing and has earned its first patent in this area.

Formally announced at the Emerging Science Technology and Innovation Conclave (ESTIC 2025), the QDM has exciting potential in neuroscience, materials research, and non-destructive testing of semiconductor chips. It can map magnetic fields across multiple 3D layers inside an encapsulated chip, making it a powerful tool for the semiconductor industry.

Developed by a team led by Prof Kasturi Saha, the QDM is based on nitrogen-vacancy (NV) centres in diamonds — tiny atomic defects that make diamonds extremely sensitive to changes in magnetic, electric, and thermal fields. The NV centres use light to detect magnetic fields through a process called optically detected magnetic resonance (ODMR). By creating a thin diamond layer rich in NV centres, the QDM can perform widefield imaging of magnetic activity, much like a high-resolution optical microscope.

As electronic devices move toward 3D chip designs, traditional diagnostic tools can no longer ‘see’ inside complex, multi-layer circuits. The QDM solves this challenge by offering direct, high-resolution 3D magnetic mapping of chips, batteries, and microelectronic systems.

Prof Saha’s team now plans to combine the QDM with AI and machine learning to create a next-generation imaging platform for chip diagnostics, biological imaging, and geological magnetic studies — all enabled by precise, 3D magnetic field visualisation.

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Published on November 17, 2025

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At a regulatory crossroads

by Hansraj Agrawal | Nov 17, 2025 | Science

LIFE-GIVING GRAFT: Genetic engineering of pigs makes xenotransplantation more feasible
| Photo Credit:
wildpixel

Some years ago, a patient with a failed liver was given a genetically modified liver of a pig. The patient passed away after 171 days. However, the case held out the promise of extended survival rates. The cross-species organ transplantation — xenotransplantation — was discussed in a paper published in the Journal of Hepatology.

Research into xenotransplantation holds hope for patients who require transplants but have too few human donor options. India faces a severe crisis in organ availability.

More than half a million people are estimated to need organ transplantation annually. However, the country has one of the lowest rates of deceased donors globally — about 0.5 per million population.

Xenotransplantation is seen as one way to solve organ shortages.

Advances in the genetic engineering of pigs have made this process more feasible internationally.

In another paper, published in the journal Transplantation Reports and titled ‘Xenotransplantation in India: Ethical challenges, historical lessons, and future prospects’, the authors (Soumyadip Sain and Trisha Chattoraj) highlight examples of US surgeons who successfully implanted gene-edited pig kidneys into patients. China has also performed a gene-edited pig liver transplant.

They point out that India’s context is unique due to a historical event that continues to influence public trust. In January 1997, Dr Dhaniram Baruah attempted a pig-to-human heart transplant in Assam. The recipient, a 32-year-old man, died within a week due to organ failure.

This transplant was unauthorised. It lacked ethical approval, governmental authorisation, and institutional oversight. Dr Baruah was arrested under the Transplantation of Human Organs and Tissues Act (THOTA), 1994, and his licence was later revoked. This episode established xenotransplantation in the Indian public consciousness as ‘controversial’.

Missing policy

India has no existing clinical research or regulatory policy on transplantation of organs from animals to humans. THOTA, too, does not address cross-species transplants.

Neither the Central Drugs Standard Control Organisation (CDSCO) nor the Indian Council of Medical Research (ICMR) have published any related guidelines, unlike their US and European counterparts.

The paper also points to India’s lack of regulatory preparedness for interspecies grafts, and the absence of a national registry to enable follow-ups on xenograft recipients or track long-term outcomes, which are critical to estimate safety for prospective patients. A new ‘Xenotransplantation Act’ or major amendments to THOTA are needed to address these gaps.

The use of animal, particularly pig, organs poses significant challenges in India’s multi-religious society. While some Indians could consider xenografts unacceptable due to religious beliefs, others could view porcine sources as unclean, not to mention viewing the killing of animals for organ transplant as an act of violence. Introducing pig organs into clinical use requires transparent communication and careful religious consultation.

Reinforcing equity

Critical, and as a prerequisite to cross-species transplants, are trials that help estimate efficacy.

The paper asserts that India lacks the infrastructure to begin trials. Currently, the country does not have ‘specific pathogen-free’ (SPF) pig colonies, which are essential for xenograft suitability. “Establishing these colonies requires extensive bio-secure facilities and specialised genetic engineering capabilities.”

Xenotransplantation could also prove expensive — $300,000 to $1 million per organ, according to US estimates. In India, where more than 70 per cent of health expenditure is out of pocket, this technology risks widening existing healthcare inequities.

The authors argue that, to move forward, India needs to fund SPF animal facilities, establish dedicated research centres, and initiate a public dialogue involving religious scholars and ethicists. The country, they say, must also establish centralised ethical oversight and incorporate xenotransplantation in the ICMR’s priority research agenda.

As important and urgent would be the establishment of a legal framework addressing animal rights, zoonotic risk, and trial safety; centralised ethical oversight panels and biosafety committees; and fast-track research pathways within ICMR and CDSCO.

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Published on November 17, 2025

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Epidemiology-ML collab decodes India’s struggles with air quality

by Hansraj Agrawal | Nov 17, 2025 | Science

WINTER WOE: Delhi’s annual date with smog and respiratory illness
| Photo Credit:
SUSHIL KUMAR VERMA

Asthma has long been one of India’s public health burdens, a condition that markedly worsens with heightened pollution levels. Each winter, when smog settles over the northern plains and cities like Delhi record some of the world’s highest particulate concentrations, hospital admissions rise and millions struggle to breathe.

A recent study uses artificial intelligence to map the link between polluted air and asthma. The research team — Gauresh Bhandary, Gurleen Kaur and Chandra Mohan Kumar — used a type of AI known as ‘physics-informed neural network’ (PINN) to reconstruct the unseen, time varying forces that link pollution and asthma. Their approach blends epidemiological modelling with machine learning, allowing the system to learn from data while remaining rooted in concepts of asthma biology and environmental behaviour.

They began by building a mathematical model that divides the population into sub-groups such as susceptible individuals, smokers, those exposed to pollution, undiagnosed and diagnosed asthma cases, and people who have recovered. The model also tracks ambient pollutants, treating particulate concentration as a dynamic quantity that rises, falls and influences the movement of people between the health states. Parameters such as the rate at which pollution leads to new asthma cases, or the pace at which pollutants accumulate, were allowed to vary over time. These are quantities that cannot be directly observed in real settings.

While a conventional neural network attempts to learn patterns directly from data, a PINN follows the scientific laws that govern the system under study. In this study, the asthma model is expressed as a set of differential equations that specify how people move between the health states and how pollutants change over time.

The researchers trained the model on synthetic data, which allowed them to control the ground truth while introducing realistic levels of measurement error. They used a numerical solver inside the neural network itself, which made the entire forecasting process differentiable. The PINN learns continuous curves that describe how the pollution-related parameters evolve through the year. These curves must allow the differential equations to generate trajectories that match the observed data and remain physically plausible.

The PINN recovered the time varying pollution effects with an accuracy rarely seen in epidemiological inverse problems. It correctly reproduced the oscillations in pollution-induced asthma during the post-monsoon and winter seasons. It captured the gradual depletion of pollutants through natural processes and the slow build-up associated with agricultural burning, industrial output and heavy traffic. Errors stayed well below two per cent. The PINN was reconstructing the hidden environmental drivers.

By linking real-time pollution readings to evolving asthma risks, the model offers a way to anticipate seasonal surges, to support hospital preparedness and pollution-control policies. Since it works even with limited or imperfect data, it can support regions where health reporting remains sparse.

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Published on November 17, 2025

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