From France to Finland: Sujie Yu’s interdisciplinary study of sound insulation materials

News

From France to Finland: Sujie Yu’s interdisciplinary study of sound insulation materials

Published: 13.12.2024

A doctoral student from PSL University explores cellulose-based aerogels as sustainable and efficient materials for acoustic properties during her research visit at 911��.

Anechoic Chambers at Acoustics Labs. Photo by Mikko Raskinen — Anechoic Chambers at Acoustics Labs. Photo: Mikko Raskinen

Sujie Yu, a doctoral student at PSL University in Sophia-Antipolis (France), carried out a research visit in Multifunctional Materials Design (MMD) research group in October-November 2024 during which she focused on exploring sound insulation by cellulose-based aerogels.

Noise pollution is seen as one of the major challenges of our modern life due to adverse health effects of noisy environment. Therefore, it is crucial to reduce human exposure to excessive noise to protect the wellbeing of populations. “Most commercial absorption materials not only contribute to environmental pollution during production and use but also pose health and safety risks to humans,” says Sujie, “And it is urgent for us to develop new porous sound absorption materials that are durable, safe, lightweight and thin while providing absorption capacities equal to or even exceeding those of current commercial acoustic materials.”

In her research, Sujie has been working on the 3D printing of gels and aerogels for biomedical applications. Aerogels are nanomaterials with low density (0.1–0.2 g/cm3), high porosity and high specific surface area (above 100 m2/g). During the research visit at Aalto, Sujie mainly focused on cellulose-based aerogels trying to understand their potential in being used as sustainable and economically viable sound absorption materials: “In MMD group, they did a very good job with experimental studies of soft materials, and I am really curious to learn more about it and to see myself what they are doing and how they are doing it.”

The research study of acoustic properties of cellulose-based aerogels was implemented as part of the BCN-ACU project in collaboration with Aalto Acoustics Lab. Sujie explored a range of materials such as cellulose aerogels and cryogels, methylcellulose aerogels and cryogels, carboxymethylcellulose cryogels and nanocellulose cryogels: “I would like to understand which material – aerogel or cryogel – is the best material for sound absorption.” The aim was to establish a comprehensive understanding of aerogels structure and their acoustic properties relationships. This would help to map ways of improving the sound absorption properties in the future.

Talking about the research methodology, Sujie mentioned that it all started with the preparation of aerogels in her French lab via supercritical carbon dioxide drying. The samples were then brought to Finland to be tested in Aalto Acoustics Lab using the 3-microphone impedance tube equipment: “It is a super nice device for testing acoustic properties, and I have learned a lot through this experiment.”

Sujie emphasizes the interdisciplinary nature of the study as in her lab at PSL the research focus is on a totally different area: “Interdisciplinarity is very important in my research. Prof. Jaana [Vapaavuori] in MMD group is focused on developing new materials and also preparing aerogels, so I can compare different properties between our two groups, and in Tapio’s group [‘Virtual Acoustics’ group led by Prof. Tapio Lokki] we did something totally different from my previous experiment.”

This kind of collaboration, according to Sujie, provides a great opportunity for acquiring new knowledge and learning new skills, expanding her vision on research work in different labs and showing new perspectives on problem-solving. It is also a great way to learn more about a different culture.

Valuable lessons of being a researcher

One of the biggest lessons for Sujie relates to lab work, particularly to the safety and accuracy of lab tests: “Safety is always the most important aspect when carrying out experiments. Previously, I experienced injuries from lab accidents, underscoring the importance of proper precautions. Moreover, our experiments should be accurate to ensure that the results are reproducible by other researchers.”

Sujie also highlights the value of critical thinking, especially when interpreting results and writing scientific articles: “That’s what my supervisor Prof. Tatiana Budtova always told me - not just working but also thinking critically about what we are doing and why.”

Contact information

Sujie Yu
Email: sujie.yu@minesparis.psl.eu