Materials scientist Nguyen Duc Hoa: 'Nanomaterials are so interesting!'
Báo Thanh niên•31/05/2024
As an applied physicist, have you ever been "fascinated" by the romance and philosophy of theoretical physics? -The practicality and feasibility of theory are very important because a theory can open up new perspectives on physical phenomena, leading to new technologies that have never been thought of. Abstract concepts can lead to practical applications in nanotechnology, new materials, medicine and quantum information... Therefore, the romance and philosophy of theoretical physics not only attract but also complement the practicality of applied physics, creating an exciting journey of discovery and creativity. Combining theoretical physics and experimental physics will bring a comprehensive and rich experience to physicists. I have always been interested in and motivated by theoretical problems in physics. That is why in our recent studies, there has been collaboration between experimentalists and theoretical and computational researchers. The theory promises a complete understanding of fundamental principles, as well as providing a comprehensive foundation from which new perspectives on physical phenomena can be opened.
Prof. Dr. Nguyen Duc Hoa (left) with his inspirational teacher - Prof. Dr. People's Teacher Nguyen Duc Chien
Can you explain in an easy-to-understand way one of your main research subjects: why do nanomaterials have so many surprising properties? - Nanomaterials operate at the atomic and molecular level, where the physical laws commonly found at large sizes no longer apply, including size effects at the nanoscale, differences in surface/volume ratio, quantum effects, and strong interactions between atoms at the nanoscale. This creates novel physical, chemical, and biological properties, opening up a wide range of potential applications. That is the excitement of nanomaterials in many fields such as medicine, electronics, energy, etc. A special example is the element gold (symbol Au): when at large sizes it is yellow and insoluble in water; but when broken down to nano size, it can be red, blue, or other colors depending on the particle size. Quantum dots are semiconductor nanoparticles with special optical properties: when excited, they emit light whose color depends on the particle size. Quantum dots are used in TV screens (QLED), LED lights, and medical applications such as imaging fluorescent markers for disease diagnosis.
With friends from Hanoi National University of Education
What are 1D and 2D materials? Aren't the materials we see 3D? - The world we perceive is a 3D spatial world. When one dimension is much larger than the other two dimensions, the object can be considered 1-dimensional - that is, a 1D material; or when two dimensions are much larger than the other one, the object is almost 2-dimensional - that is, 2D. At the nanoscale, 1D and 2D materials have many unique properties because their atomic structure is limited to 1 or 2 dimensions. A 1D material such as carbon nanotubes (hollow cylindrical tubes with diameters <100 nanometers and lengths of up to several micrometers or more) has extremely high specific tensile strength and good electrical and thermal conductivity. A nanowire (with a diameter < 100 nm and a very large length/diameter ratio, can be made from many different materials such as metals, semiconductors and metal oxides... can be used in sensors or electronic components. A 2D material such as graphene (with a layer of carbon atoms arranged in a honeycomb network) has very durable mechanical properties, good electrical and thermal conductivity, and is the foundation for many studies and applications in electronics, energy and transparent electrodes... With nanotechnology, 1D and 2D materials are increasingly developing and have diverse applications, contributing to expanding human understanding of the physical world and promising breakthrough technological advances in the future.
With colleagues at ITIMS
Is it true that the smaller the particles of materials are, the more surprises and potential applications there are? If we divide the particles to the very end, what are we left with? - This question is very interesting and helps clarify some basic principles in materials science and nanotechnology. Indeed, when we divide the particles of materials to the nano size, many new and surprising properties appear. As we continue to divide the particles, we will approach the most basic level of matter, that is, atoms and subatomic particles such as protons, neutrons, quarks, leptons, and bosons - which are currently the smallest constituent units of materials. However, in the future, it is possible that more fundamental particles will be found, or predicted to exist. That is the driving force for materials scientists, because science has no end. These are also the realms of romance, imagination, and philosophy in theoretical physics.
Nanoparticles have been found in many artifacts since ancient times. What makes nanomaterials so important to modern society? -Nanomaterials are so important to modern society not only because of their small size, but mainly because of their unique properties and the wide range of potential applications they offer. Although nanoparticles have existed since ancient times (e.g. the Lycurgus Cup will appear different colors when viewed under reflected or transmitted light), their understanding and control have advanced dramatically in recent decades, opening up many new and groundbreaking applications in many fields. Thus, the ability to manufacture and control nanomaterials is the secret. Nanotechnology not only opens up new potential for current applications but also creates breakthrough opportunities in the future, contributing positively to global economic and social development.
With ITIMS colleagues in Ba Vi
What about superconducting materials and their applications? - Superconducting materials, simply put, are materials that when an electric current is passed through it, the current will last forever without decreasing or losing energy. Superconducting materials have many different applications in fields such as medicine , power transmission, magnetic levitation trains, particle accelerators, etc. Currently, the most popular device using superconducting materials is magnetic resonance imaging (MRI) machines that use superconducting magnets to create the strong magnetic fields needed for detailed imaging inside the body. Thanks to superconducting materials, MRI machines operate more efficiently and provide higher quality images. Recently, China has successfully tested a train running on a magnetic levitation of superconducting coils in a vacuum tube, reaching speeds of up to 623 km/h (the design speed can reach 1,000 km/h). Perhaps the biggest challenge currently preventing the commercialization and widespread use of superconducting materials is the extremely low operating temperature. Superconductivity requires the use of complex and expensive cooling systems, such as liquid helium (-269oC) or liquid nitrogen (-196oC) to maintain low temperatures. Other challenges include high production costs, poor mechanical durability, complex fabrication techniques, the ability to maintain the superconducting state in strong magnetic fields, or the requirement for the superconducting state under high pressure.
Talking with colleagues in the lab
What are the new developments in the Professor's research on nanomaterial applications? - After about 10 years of basic research, with certain achievements in the field of nanomaterials and sensors, our group decided to research integrated nanomaterials for IoT (Internet of Things) applications for breath analysis to diagnose diseases. This is truly a development step and clearly demonstrates the interdisciplinary spirit in modern scientific research. The combination of nanomaterials, electronic components and IoT not only opens up new potentials for disease diagnosis but also contributes to the development of advanced medical technologies, or many applications in different fields such as industry, environment, security... Our idea was formed in 2009 when referring to the research work in Nature Nanotechnology journal led by Hosam Haick (Israel) published on the results of "Diagnosing lung cancer through breath using gold nanoparticles". This group's research shows that by comparing the breath analysis results of healthy people and lung cancer patients, it is possible to identify lung cancer patients.
Talk to an expert at an event
Our subsequent research has created a semiconductor gas sensor using nanomaterials that can provide better response, lower gas concentration detection limits than gold nano and can be fully developed for application in breath analysis for disease screening and diagnosis. This is the applied research direction in a project funded by Vingroup Innovation Foundation (VinIF) in 2019. One of the motivations for us to confidently propose this challenging project to VinIF is the "risk-taking" nature of the Foundation. Thanks to that progressive mechanism, instead of proposing a safe research direction that is sure to produce a product, we are determined to do a breakthrough topic, despite the high potential risk. The principle of this research is that when people suffer from certain diseases such as lung cancer, asthma, diabetes, etc., it will affect the body's metabolism, thereby creating characteristic gases (biological markers) with different concentrations in the patient's breath. These biological markers will change differently for each type of disease. The gas sensor is designed to identify and analyze biological markers, helping to detect diseases early without invasive methods such as biopsy. The wave of microchips and semiconductor chips is becoming hotter than ever. According to the professor, in which direction should we take advantage of this wave? -Yes, this topic is very hot and is the center of many researches, developments and applications of modern technology. The growth and progress in this field not only promotes the development of information and communication technology but also has a profound impact on many other industries. But to be honest, our semiconductor and microchip team is still too small, with limited expertise. In addition, in Vietnam today, we do not have a strong enough semiconductor research center, and also lack a semiconductor ecosystem. In my opinion, Vietnam should take advantage of the wave of semiconductor and microchip technology development by focusing on niche areas with competitive potential, investing in R&D and human resource training, building a technology ecosystem and supporting industries, and applying technology to key industries. These strategies will help Vietnam develop sustainably and compete effectively in the rapidly changing global technology context. Thank you, Professor!
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