Pham Thi Hong, a doctoral student in Solid-State Physics at Vietnam National University, Hanoi (VNU-HN), is one of the two recipients of the Ryoichi Sasakawa Young Leaders Fellowship Fund (Sylff) for the academic year 2023 - 2024
Pham Thi Hong and her colleagues conducted research on "Investigating the Radiative Cooling Effect Using Oriented Dielectric Materials for Practical Applications" with the aim of identifying surface cooling materials that do not consume energy, thereby reducing energy consumption for air conditioning, reducing CO2 emissions from cooling devices, and creating a cool environment for everyone in the summer.
Hong said that her passion for physics led her to study at VNU-HN, one of the leading institutions in basic research. During her four years of undergraduate study, her passion for science grew as she participated in classes, completed her thesis, and engaged in various fascinating scientific projects, learning many research skills while working with professors at the university.
"After graduating from university, my passion for science grew even stronger, so I continued my studies at a higher level. I participated in scientific projects with professors, mentored students, and exchanged research internationally to satisfy my scientific passion. At the same time, I hope that the results of fundamental scientific research will be applied practically," Pham Thi Hong said.
Cooling materials that do not consume energy
In Vietnam, the demand for electricity for air conditioning in the summer is very high, while the shortage of electricity for daily activities is increasing. Most people choose cooling devices such as air conditioners or air coolers. Therefore, electricity consumption increases significantly in the summer, leading to power shortages and environmental impacts. Researchers estimate that air conditioning is responsible for emitting the equivalent of 1,950 million tons of carbon dioxide (CO2) annually, accounting for 3.94% of global greenhouse gas emissions. Global warming is a serious issue, being a concern of all countries around the world, including Vietnam.
To address this issue, Pham Thi Hong and her colleagues proposed the topic "Investigating the Radiative Cooling Effect Using Oriented Dielectric Materials for Practical Applications" with the aim of reducing energy consumption for air conditioning, reducing CO2 emissions in the environment caused by cooling devices, and creating a cool environment for everyone in the summer.
The goal of the project is to identify surface cooling materials that do not consume energy. As a result, passive cooling layers help reduce cooling costs for buildings by up to 30%. Therefore, passive cooling materials help save cooling energy, especially in the summer when electricity demand is high. In 2023, severe power shortages are expected, while the demand for air conditioning will be high in the summer. Passive cooling layers will help save cooling costs. The problem to be solved is to reduce CO2 emissions and electricity consumption for air conditioning. Moreover, radiative cooling materials contribute to the global "Net Zero" goal and reduce carbon-neutral certificates to protect the environment. When this issue is resolved, many people will have a comfortable living space in the summer.
Over the past two years of research on this topic, Hong's research team has successfully developed passive cooling products based on particles of various sizes mixed in an acrylic resin. It has the ability to reflect up to 98% of solar radiation energy incident in the wavelength range from 0.3 - 2.5 μm and selectively radiate up to 93% in the transparent atmosphere window in the wavelength range from 8 - 13 μm. Therefore, the surface temperature covered by the passive cooling layer is approximately equal to the shade temperature during the day and lower than the air temperature by 2 - 8°C at night. From these results, the team affirmed that passive cooling materials will be a solution to heat mitigation and cooling in the summer. The team believes that the passive cooling layer contributes to reducing electricity consumption and CO2 emissions. Furthermore, this material does not emit pollutants such as chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) from air conditioners, which pollute the environment and damage the ozone layer. Therefore, passive cooling materials contribute to environmental protection. Moreover, this material does not consume energy, so it can be applied widely and can be applied to various surfaces such as metal, walls, wood, cement... and easy to install. Therefore, passive cooling materials can be used for houses in hot, harsh climates, people living in remote areas with difficult economies; used to solve cooling problems for livestock, improving livestock productivity.
On the other hand, the cooling material has a lower temperature than the air temperature at night from 2 - 5°C due to the ability to radiate electromagnetic waves directly into space in the transparent atmosphere window from 8 - 13 μm. This will be a promising result in the application of collecting clean water from nature. Because the surface has a lower temperature than the air temperature under the shade, it has the ability to condense water vapor at night. This experiment is suitable for high altitudes where there is a shortage of water for domestic and irrigation purposes, or remote islands with limited fresh water sources. Therefore, Hong and her colleagues are designing and developing a water collection device, with an expected result of 2-3 liters of water per night. This water source provides irrigation water for people or can be filtered into daily drinking water products. This will be a promising solution to address the problem of water shortages in island and highland areas.
Pham Thi Hong's project was evaluated by the Nippon Foundation, Japan, and VNU-HN as having high applicability, promising to contribute to solving social issues such as livelihoods, environmental protection, and sustainable development not only for Vietnam but also for the world, in line with the philosophy and goals of the Sylff Scholarship and the Nippon Foundation as well as the agreement between the Nippon Foundation, the Tokyo Foundation, and VNU-HN.
The research environment maximizes research capabilities and creativity
Pham Thi Hong said she was honored to receive the Sylff scholarship. Since some measurements in the research process have to be carried out abroad at high costs, Hong will use this scholarship partly for tuition fees and partly for measuring experimental samples.
"I will continue on the path of scientific research and discover many practical applications for various materials. The goal is to commercialize research products in the laboratory and have high practical applications," Pham Thi Hong expressed.
During her studies and research at VNU-HN, Hong's research was mainly conducted at the Nano and Energy Center, University of Science. Pham Thi Hong and other researchers used existing facilities, manufactured samples, and performed basic optical and thermal measurements using equipment from the Physics Department and University of Science.
Pham Thi Hong shared: "The professors at the University of Science with their expertise always support us in the research process and data analysis. The university also provides opportunities to use available equipment as well as regularly informs us about exchange programs and scholarships, creating favorable conditions for us to develop not only domestically but also internationally. With strong potential in science and technology and high-quality human resources, VNU-HN provides conditions and a favorable environment for researchers to maximize their research capabilities, creativity, and promote the commercialization of research results into society."
The Ryoichi Sasakawa Young Leaders Fellowship Fund (Sylff) is a collaborative initiative of the Nippon Foundation, the sponsor, and the Tokyo Foundation for Policy Research, the program manager. Sylff is inspired by the vision of Ryoichi Sasakawa, a philanthropist and founding chairman of the Nippon Foundation, and was launched in 1987 to support outstanding students with high leadership potential pursuing postgraduate research in social sciences and humanities. In Vietnam, VNU-HN and VNU-HCM are honored to be among 69 prestigious universities from 44 countries around the world to receive support from the Nippon Foundation as a fellowship fund to train young talents to meet the development needs of the country.
