Chemical and microstructural characterization of graft-type polymer electrolyte membranes

Abstract The chemical and microstructural features of poly(styrenesulfonic acid) (PSSA)-grafted poly(ethylene-co-tetrafluoroethylene) (ETFE) polymer electrolyte membranes (ETFE-PEMs) through preparation procedures and grafting degree (GD) are investigated by solid-state 13C cross polarization/magic angle spinning solid-state nuclear magnetic resonance (13C CP/MAS NMR) spectra, atomic force microscope (AFM), X-ray diffraction (XRD), and Doppler broadening (DB) of positron-annihilation radiation measurement. Especially, sequential order in the structural changes as a response to GD increase is discussed in detail by using the two-dimensional correlation spectroscopy (2D-CS) analyses. The grafting process at –CH2 sites occurs earlier than that at –CF2 ones. The chemical degradation of ETFE-PEMs (even at a low GD of 8.8 %) observed previously...

Nữ sinh Trường Đại học Khoa học tự nhiên được vinh danh Công dân trẻ tiêu biểu TP.HCM năm 2025

Nữ sinh Trường Đại học Khoa học tự nhiên được vinh danh Công dân trẻ tiêu biểu TP.HCM năm 2025

Với thành tích nổi bật trong học tập, nghiên cứu khoa học và cống hiến cho cộng đồng, sinh viên Võ Ngọc Minh Anh – Khoa Công nghệ Thông tin, Trường Đại học Khoa học tự nhiên, ĐHQG-HCM, đã được vinh danh tại lễ tuyên dương “Công dân trẻ tiêu biểu TP.HCM” năm 2025, do Thành Đoàn TP.HCM tổ chức ngày 01/01/2026. Tại lễ tuyên dương, Minh Anh là một trong những gương mặt trẻ tiêu biểu trong lĩnh vực khoa học – công nghệ, đồng thời là đại diện nữ hiếm hoi được vinh danh năm nay. Danh hiệu...

Trở về kiến tạo tương lai công nghệ

Trở về kiến tạo tương lai công nghệ

Sau nhiều năm học tập, nghiên cứu và giảng dạy tại Hoa Kỳ, TS Trương Trung Kiên đã lựa chọn trở về Việt Nam, gắn bó với Trường đại học Khoa học tự nhiên – Đại học Quốc gia TP.HCM, mang theo khát vọng đóng góp cho khoa học công nghệ nước nhà và đào tạo thế hệ kỹ sư tương lai. Ông là một trong những gương mặt tiêu biểu của Chương trình VNU350. Tốt nghiệp tiến sĩ ngành kỹ thuật điện và máy tính tại Đại học Tổng hợp bang Texas (Hoa Kỳ), Trương Trung Kiên sở hữu...

Simple fabrication of green materials from tin dioxide and biocarbon from cashew residue as anodes for advanced Li-ion batteries

Abstract In the present work, composites of SnO2 and biocarbon from cashew residue were applied and reported for the first time as anode materials of Li-ion batteries. The composites were developed via a two-step synthesis route consisting of pretreating the cashew residue to create biocarbon, followed by compositing the biocarbon with SnO2. The calcination temperatures were set at 400 °C and 500 °C, and the synthesized samples were denoted as SOC400 and SOC500, respectively. These temperature points were chosen to be significantly lower than those used in previous studies to reduce production costs and enhance commercial competitiveness. The properties and morphologies of the...

Cost-effective sulfonate-modified PEO/PVDF electrolytes toward high-performance solid-state lithium batteries

Abstract Safety concerns in lithium-ion batteries (LIBs) poses safety risks due to flammable liquid electrolytes and dendrite formation. Solid polymer electrolytes (SPEs) offer a safer alternative, though limited by low ionic conductivity and poor dendrite resistance. In this study, a SPE based on poly(ethylene oxide) (PEO) was modified to by blending with polyvinylidene fluoride (PVDF) to enhance mechanical strength and reduce crystallinity, while introducing sulfonate (SO3−) groups from linear alkylbenzene sulfonic acid (LABSA) to improve ion transport. At the optimized ratio of PEO:PVDF (1:0.7) and PEO:LAS (1:1.0), the SPE with LiTFSI exhibited high Li+ ion transference number (0.48) and improved diffusion...

Fast and facile controlled synthesis of silver nanocubes using the solvothermal process to create SERS substrates for detecting polystyrene microplastics

Abstract The approach for detecting trace amounts of microplastics using surface-enhanced Raman spectroscopy (SERS) faces a significant challenge because the size of individual nanoparticles is considerably smaller than that of microplastics. Therefore, it is imperative to develop a type of nanoparticle that can form a larger surface area while still preserving excellent surface plasmon properties to enhance SERS analysis. Silver nanocubes (AgNCs) are an ideal candidate for meeting these specific requirements. Although prior studies have successfully investigated the impact of chemical parameters, it remains a challenge to synthesize AgNCs homogeneously. The current research underscores other experimental refinements that have been...

Countering Side-Channel Attacks With a Dynamic S-Box Based on Affine Transformations and Gold Sequences

Abstract Advanced cryptographic devices employ multiscale countermeasures to bolster resilience against side-channel analysis (SCA). In masking-based defenses, secure substitution-boxes (S-boxes) and effective masking schemes are paramount. Additionally, the time-based hiding techniques, leveraging multiple clocks for individual encryption operations, offer significant protection. This article introduces a novel multiscale countermeasure: an improved tower field masking scheme integrated with an affine transformation-based dynamic S-box. Crucially, we incorporate Gold sequences to generate both a random clock source for horizontal hiding and random values for masking. Extensive evaluation using up to five million power traces demonstrates the robustness of our approach against standard correlation power...

The complete version of Kursov’s theorem for matrices over division rings

Abstract Let D be a division ring with center F, and let n > 1 be an integer. A known result due to Kursov asserts that if D is finite-dimensional over F, then the commutator width of the general linear group GLn(D) is at most one greater than that of GLn(D). In the absence of the finite-dimensionality assumption, recent research has made significant progress, though the developments typically cease once F is infinite or D is algebraic over F. The purpose of this paper is to show that these restrictions are, in fact, unnecessary. Tran, N.S. (2026) Linear Algebra and its Applications, 728, pp. 376–382. DOI: https://doi.org/10.1016/j.laa.2025.09.015

Thermoelectric properties of MoS2 thin films prepared by RF magnetron sputtering

Abstract In this work, we investigated the thermoelectric properties of MoS2 thin films deposited on SiO2/Si wafer substrates as prepared by the radio frequency (RF) magnetron sputtering technique. A fixed sputtering power of 200 W was maintained for 30 min to facilitate thin film deposition. After thin film deposition, as-deposited thin films were annealed by the vacuum annealing method at 550, 650, and 700 °C. The crystal structure, morphology, film thickness, and atomic composition of the MoS2 thin film were characterized using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDS) techniques, respectively. The elemental states of thin films were determined...

Using Low-Speed Rotation in Heparin Immobilization Improved Antithrombogenicity of Tubular Acellular Vascular Scaffolds

Abstract Background: Acellular tubular artery scaffolds offer structural support for vascular regeneration but are inherently limited by poor anticoagulant properties, which increases the risk of thrombus formation following implantation. This thrombogenicity remains a major obstacle to their clinical application, particularly in small-diameter vascular grafts. Methods: To address this challenge, the present study investigates the use of the Layer-by-Layer (LbL) assembly technique for heparin immobilization under low-speed rotation. Utilizing a roller tube system, heparin was immobilized onto decellularized scaffolds through electrostatic interactions facilitated by a DHI-based linker. This low-speed rotation LbL approach enhanced the uniformity and stability of heparin deposition compared...