On Feb 27, 2024, the Institute of Materials Science appointed us, including Assoc. Prof. Nguyen Thanh Tung, Dr. Dao Nguyen Thuan, and Dr. Nguyen Nhat Linh, the excellent research group of plasma technology and applications. This appointment recognizes the outstanding contributions and expertise of the group in the field of plasma technology and its diverse applications. As part of the excellent research group of plasma technology and applications, we will continue to lead cutting-edge research projects, collaborate with industry partners, and mentor the next generation of researchers in this field.

On Jan 16, 2024, the Vingroup Innovation Foundation (VINIF) held a ceremony to announce the awarding of 2023 postdoctoral scholarships in Vietnam. After three rounds of rigorous selection by the scientific council, 360 scholarships worth VN 62 billion (US $ 2.6 million) were awarded to 150 master's students, 150 PhD candidates, and 60 postdocs from 13 different fields of study. Dr. Nguyen Nhat Linh, a member of PlaTech was honored to be one of them.

Our DFT calculations reveal that the structures of these clusters are influenced by dissociative adsorption of H2 but not by molecular adsorption. By conducting a comprehensive analysis, we show that the preferred adsorption configuration is a result of the competition between various factors, including the surface/encapsulated position, relative electronegativity, and coordination number of atoms. Although the dissociate adsorption is remarkably more stable than their corresponding molecular adsorption configurations, different activation energies ranging from 0.15 to 0.99 eV are required during the dissociative reaction pathway. The results shed light on the mechanisms underlying the preferred adsorption site of hydrogen on the studied species and provide insights into adsorption kinetics that can aid further theoretical and experimental studies of hydrogenation in nanostructured materials.

https://www.sciencedirect.com/science/article/pii/S0009261423005432 

Members of the 2023-2028 Standing Committee show their gratefulness to Prof. Nguyen Duc Chien - President of VMRS 2019-2023 and members of the 2019-2023 Standing Committee Prof. Le Quoc Minh, Prof. Nguyen Hoang Luong (absent), Prof. Pham Duc Thang (absent).

The development of new materials has been strongly linked to the competitiveness of national science and technology as well as manufacturing company technology from the past to the present. The paradigm for global new material development is changing from limited development methods by field in the past to openness, integration, and convergence, and is accelerating through cooperation in various technology fields such as material science, mathematics, and computer science.

The 7th Asian Materials Data Symposium (2023 AMDS) was held at Hotel Inter-burgo Daegu in Korea from October 24 to 27, 2023, to share global issues, technologies, and agendas on data utilization areas to accelerate the development of new materials.

During the Symposium, Dr. Nguyen Hoang Tung presented our recent results on forecasting the metamaterial's electromagnetic properties using the machine learning approach. The prominent machine learning models, namely polynomial regression, random forest regression, direct deep neural network, and bidirectional deep neural network, are meticulously examined.  

More information at https://www.amds2023.com/index.php?GP=program/conference 

The Vietnam-Belgium collaboration in the field of MMs was established in 2010 when Nguyen Thanh Tung (NTT) performed his PhD program at KU Leuven under the supervision of Peter Lievens (PL) and co-supervised by Ewald Janssens (EJ) and Margriet Van Bael. His PhD (finished in May 2014) dealt with stability studies of bimetallic clusters of atoms and the development of a Stern-Gerlach magnetic deflection setup. Besides the study of clusters in the gas phase, NTT was the driving force behind a collaboration on metamaterials (bilateral NAFOSTED-FWO 2011.35 project “Taming negative refractive metamaterials” with PL and Vu Dinh Lam as principal promotors). After returning to Vietnam, NTT strengthened IMS-KU Leuven collaboration, first via student exchanges (EJ as host) and later via the project “Exploring the physical principles of electromagnetic energy harvesting in GHz and THz metamaterials” (FWO.2017.103.01) (with EJ, PL, and JVDV). This project resulted in eight ISI papers, four papers in domestic journals, two PhDs (Tran Van Huynh and Matias Bejide), and several student/scholar exchanges. PL and EJ also have been regular visitors of IMS and frequent invited speakers at the IWAMSN workshop series co-organized by NIMS Japan, IMS-VAST, and Institute of Néel (CNRS, France). The KU Leuven promoters (EJ and JVDV) have a long-standing tradition of close and successful collaboration on joint projects, using joint research infrastructure, and joint supervision of young researchers.

This project exploits the complementary expertise of the three experienced researchers that will be involved. The teams in Belgium and Vietnam have good knowledge of nanocluster fabrication (EJ and NTT), cluster deposition (EJ and JVDV), and nanofabrication techniques (JVDV and NTT). NTT is a leading expert in metamaterials research in Vietnam, while EJ has studied specific properties of metamaterials, in particular their dynamical relaxation processes. Sensing applications using SERS have been studied extensively by NTT and his colleagues at IMS. Given the complementary expertise of the teams in Belgium and Vietnam, intensive interactions are planned, including joint supervision of PhD students and research exchanges. EJ will coordinate the project on the Leuven side (project planning, take care of the dissemination of the results) and NTT will be in charge of the project at IMS-VAST.

More information at https://www.most.gov.vn/vn/tin-tuc/23158/danh-muc-de-tai-thuoc-chuong-trinh-hop-tac-song-phuong-nafosted--fwo-duoc-quy-phat-trien-khoa-hoc-va-cong-nghe-quoc-gia-tai-tro-nam-2023.aspx 

Nguyen Minh Thu, Nguyen Thi Giang and Le Thi Quynh Xuan awarded Odon Vallet 2023 for their excellency as Master and PhD students. Big congratulations!

This patent covers the technique to print GHz metamaterials instead of the conventional lift-off process. The metal patterns on dielectric FR4/Roger substrate are replaced by conductive inks on the paper, allowing advances of flexible metmaterials for novel applications.

From Aug 04 to 15, 2023, Dr. Nguyen Nhat Linh visited the Plasma Bioscience Research Center at Kwangwoon University, South Korea to collaborate in cold plasma technology. During this visit, a couple of experiments and productive discussions were carried out with Korean colleagues. 

Ms. Nguyen Thi Giang had a great defense of her Master's thesis on photocatalytic activities of hybrid organic-inorganic nanomaterials at the Hanoi National University of Education. During her Master program, Giang published several articles in good journals as a co-author (e..g. https://doi.org/10.1016/j.envres.2023.115984 and https://doi.org/10.3390/catal12121630).

Assoc. Prof. Nguyen Thanh Tung, Dr. Nguyen Hoang Tung with President Dr. Hwang and CPRI colleagues

We investigate the interaction of H2 with small-sized AgnCr (n = 1–12) using density functional theory calculations. Comprehensive analysis shows that the geometric structure of clusters, the relative electronegativity, and the coordination number of the Cr impurity play a decisive role in determining the preferred adsorption configuration.

https://doi.org/10.1021/acsomega.2c04107  

We explore superatomic clusters as analogues of more complex molecules by doping clusters with 3d transition metal atoms. It is found that, in similarity to their sister M, the structural evolution of Au9M2+ is ruled by the bond strength of AuM dimers and can be generalized into two motifs: the endohedrally doped cage-like structure for lighter dopants (M = Sc and Ti) and the slightly distorted tetrahedral structure for heavier ones. The average binding energies and dissociation energies are calculated to identify the relatively stable patterns. 

https://doi.org/10.1016/j.cplett.2022.139451   

Our new patent application relating to the kilogram-production of carbon nanospheres using the direct-current thermal plasma method has been submitted. 

We have shown that the plasma behavior of graphene plays the central role on controlling the absorption strength of a metamaterial absorber using various computational techniques. The work has been published in Photonics and Nanostructures - Fundamentals and Applications 45, 100924 (2021)

https://doi.org/10.1016/j.photonics.2021.100924 

Tran Van Huynh, Nguyen Thi Mai, Ngo Thi Lan, and Le Thi Quynh Xuan awarded Odon Vallet 2021 for their excellency as PhD students. Big congratulations!

We propose an extended two-temperature heat transfer model that can be used to investigate the heat flow in multilayer antennas and includes metallic layers, a dielectric substrate, and their respective interfaces. It is demonstrated how the heat flow dynamics in a layered material, excited by short laser pulses, can be controlled by the thermal properties of the buffer layer. 

Binary clusters of transition-metal and noble-metal elements have been gathering momentum for not only advanced fundamental understanding but also potential as elementary blocks of novel nanostructured materials. Our results show that while each noble atom contributes one s valence electron to the cluster shell, the number of chromium delocalized electrons is strongly size-dependent. The localization and delocalization behavior of 3d orbitals of the chromium decide how they participate in metallic bonding, stabilize the cluster, and give rise to and eventually quench the spin magnetic moment. The finding results are expected to provide greater insight into how a host material electronic structure influences the geometry, stability, and formation of spin magnetic moments in doped systems. 

https://doi.org/10.1021/acsomega.1c02282  

We describe the synthesis of gold nanoparticles by plasma reduction of a HAuCl4 precursor. PEG was used to improve the morphology and formation efficiency of nanoparticles during plasma synthesis of AuNPs. Next, we investigated the optical sensing properties of AuNPs using plasma-treated and untreated rhodamine B (RhB) dye. The degradation of RhB by plasma treatment was studied by optical absorption and Raman spectroscopy. For Raman spectroscopic measurements of plasma-treated RhB, AuNP-loaded paper was used as a SERS platform 

https://doi.org/10.3390/app122010308 

This study focuses on the use of polydopamine-coated gold nanoparticles (Au@PDA NPs) that showed excellent selectivity towards cancer cells and highlights the novel mechanism of Au@PDA NPs-triggered anti-tumor immunity against immunosuppressive cancers, demonstrating the potential of the Au@PDA NPs for cancer immunotherapy. 

https://doi.org/10.1016/j.jiec.2021.05.035  

We present an unprecedented single-step synthesis protocol using a non-equilibrium atmospheric pressure plasma jet to trigger the redox reaction between dopamine (DA) and gold ions in distilled water to simplify the fabrication process, eliminating the use of additional chemicals. Our data emphasize the importance of plasma–liquid interaction in synthesizing Au@PDA NPs for suppressing cancer cell growth and level of their intracellular delivery to improve cancer therapy. Hence, the Au@PDA NPs prepared by the one-pot plasma-assisted synthesis may have future biomedical applications as an anticancer agent. 

https://doi.org/10.1039/D0GC01348J   

We present an unprecedented single-step synthesis protocol using a non-equilibrium atmospheric pressure plasma jet to trigger the redox reaction between dopamine (DA) and gold ions in distilled water to simplify the fabrication process, eliminating the use of additional chemicals. Our data emphasize the importance of plasma–liquid interaction in synthesizing Au@PDA NPs for suppressing cancer cell growth and level of their intracellular delivery to improve cancer therapy. Hence, the Au@PDA NPs prepared by the one-pot plasma-assisted synthesis may have future biomedical applications as an anticancer agent. 

https://doi.org/10.1063/1.5102106    

Thin film of amorphous tungsten-doped cobalt oxide (W:CoO) was successfully grown on a conducting electrode via an electrochemical oxidation process employing a [Co(WS4)2]2− deposition bath. The as-prepared W:CoO belongs to the best cobalt oxide-based catalysts ever reported for the oxygen evolution (OER) reaction. 

https://doi.org/10.1002/asia.201800401