|
ZetaPALS相位分析光散射原理（PALS）測ζ電位應用案例6
文獻名：Reduced aggregation and sedimentation of zero-valent iron nanoparticles in the presence of guar gum
作者：Alberto Tiraferria, Kai Loon Chenb, Rajandrea Sethia, Menachem Elimelechb
（aDITAG – Dipartimento di Ingegneria del Territorio, dell’Ambiente e delle Geotecnologie, Politecnico di Torino, Corso Duca degli Abruzzi, 24, 10129, Torino, Italy
bDepartment of Chemical Engineering, Environmental Engineering Program, Yale University, New Haven, CT 06520-8286, USA）
摘要：Injection of nanoscale zero-valent iron (NZVI) is potentially a promising technology for remediation of contaminated groundwaters. However, the efficiency of this process is
significantly hindered by the rapid aggregation of the iron nanoparticles. The aim of this study was to enhance the colloidal stability of the nanoparticles
through the addition of the “green” polymer guar gum. We evaluated the properties of guar gum and its influence on the surface properties, particle size,
aggregation, and sedimentation of iron nanoparticles. Commercial iron nanoparticles were dispersed in guar gum solutions, and their aggregation and sedimentation
behaviors were compared to those of bare iron nanoparticles and commercial nanoparticles modified with a biodegradable polymer (polyaspartate).
High performance size exclusion chromatography, charge titration, and viscosity assessment showed that guar gum is a high molecular weight polymer
which is nearly neutrally charged, rendering it suitable for steric stabilization of the iron nanoparticles. Electrophoretic mobility measurements demonstrated
the ability of guar gum to adsorb on the nanoparticles, forming a slightly negatively charged layer. Dynamic light scattering experiments were conducted to
estimate the particle size of the different nanoparticle suspensions and to determine the aggregation behavior at different ionic strengths. Guar gum effectively
reduced the hydrodynamic radius of the bare nanoparticles from 500 nm to less than 200 nm and prevented aggregation of the nanoparticles even at very high
salt concentrations (0.5 M NaCl and 3 mM CaCl2). Sedimentation profiles of the different nanoparticle suspensions confirmed the improved stability of the iron
nanoparticles in the presence of guar gum. The results strongly suggest that guar gum can be used to effectively deliver stabilized zero-valent iron nanoparticles for remediation of contaminated groundwater aquifers.
關鍵詞：Zero-valent iron nanoparticles; Guar gum; Green polymers; Aggregation; Steric stabilization; Groundwater remediation; DLS; Particle size
|
