Stability Characteristics of Trisodium Citrate–Stabilized Silver–Water Nanofluids

Silver nanoparticles (AgNPs) exhibit special properties due to their large surface area-to-volume ratio. The liquid state of AgNPs enables them to be handled well for some special applications. Silver–water nanofluids (NFs, dispersion of AgNPs in water) can be used in mass transfer for 3D printing industries for printed electronics, heat transfer, and drug delivery including many other applications. Before such applications, stable silver–water NFs are needed to prepare. Therefore, this paper reports the preparation and stability assessment of 2 vol% silver–water NFs. First, size-controlled one-pot facile synthesis of silver nanoparticles was performed by chemical reduction method using AgNO3 as a precursor (P), hydrazine as a reducing agent (RA), and trisodium citrate as a capping agent (CA). AgNPs were synthesized with the different molar ratios of P: RA: CA=1:3:0, P: RA: CA=1:3:3, P: RA: CA=1:3:6; P: RA: CA=1:3:9, and P: RA: CA=1:3:12. To be confirmed about AgNPs production, synthesized products were characterized by ultraviolet-visible spectroscopy (UV-vis), X-ray diffraction (XRD), scanning microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, transform electron microscopy (TEM). Next, 2.0 vol% AgNPs-water NFs was prepared by adding the required amounts of AgNPs to water. Then, the stability of the prepared NF was evaluated through observation and comparison of sedimentation with different time laps, UV-vis spectrum analysis, zeta potential measurement, and dynamic light scattering (DLS). The prepared 2 vol% AgNPs-water NFs showed silver NF's stability for at least two weeks. These results imply that the silver-water NFs have the potential for many industrial applications such as heat, mass transfer, and drug delivery, etc. Dhaka Univ. J. Sci. 74(1): 160-167, 2026 (January)