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Delforce L, Hofmann E, Nardello-Rataj V, Aubry JM. TiO2 nanoparticle dispersions in water and nonaqueous solvents studied by gravitational sedimentation analysis: Complementarity of Hansen Parameters and DLVO interpretations. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.127333] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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2
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Koshevaya E, Nazarovskaia D, Simakov M, Belousov A, Morozov V, Gandalipov E, Krivoshapkina E, Krivoshapkin P. Surfactant-free tantalum oxide nanoparticles: synthesis, colloidal properties, and application as a contrast agent for computed tomography. J Mater Chem B 2021; 8:8337-8345. [PMID: 32794534 DOI: 10.1039/d0tb01204a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
With the growing interest of the medical industry in biocompatible nanoparticles (NPs), the current synthetic methods should be adapted to appropriate demands (toxicity, scalability, etc.). Most applications require colloidal systems to be stable not only in water but also in vivo, which represents a major challenge. In this study, biocompatible Ta2O5 NPs were synthesized by a solvothermal method avoiding toxic reagents, and surfactant-free stable hydrosols were obtained and used for computed tomography (CT) imaging. The small hydrodynamic size (2 nm) and colloidal stability of primary NPs were studied by dynamic light scattering (DLS). The particles were characterized by X-ray diffraction, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and Brunauer-Emmett-Teller analysis to confirm their structure and purity. To develop a stable hydrosol preparation protocol, the influence of pH and ultrasonication duration on the stability of Ta2O5 sols was analyzed by DLS and microelectrophoresis. To enhance the understanding of NP behavior in vivo, sol stability in conditions close to physiological (NaCl solutions) was studied in a pH range of 3-9. Hydrosols prepared by the proposed protocol were stable for at least 6 months and exhibited negligible cytotoxicity. Ta2O5 NPs also showed high CT contrast both in theoretical calculations and in vivo (rat gastrointestinal tract).
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Affiliation(s)
- Ekaterina Koshevaya
- Institute of Chemistry of Federal Research Center "Komi Science Centre of the Ural Branch of the Russian Academy of Sciences", Syktyvkar 167000, Russia
| | | | - Matvey Simakov
- Veterinary Clinic Named after Ivan Fillmore, St. Petersburg 194358, Russia
| | - Alexandr Belousov
- State Research Center - Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow 123182, Russia
| | - Vladimir Morozov
- State Research Center - Burnasyan Federal Medical Biophysical Center of Federal Medical Biological Agency, Moscow 123182, Russia
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3
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Gordillo-Delgado F, Zuluaga-Acosta J, Restrepo-Guerrero G. Effect of the suspension of Ag-incorporated TiO2 nanoparticles (Ag-TiO2 NPs) on certain growth, physiology and phytotoxicity parameters in spinach seedlings. PLoS One 2020; 15:e0244511. [PMID: 33373403 PMCID: PMC7771677 DOI: 10.1371/journal.pone.0244511] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 12/11/2020] [Indexed: 11/18/2022] Open
Abstract
In this work, the effect of the inoculation of silver-incorporated titanium dioxide nanoparticles (Ag-TiO2 NPs) in spinach seeds was evaluated on certain growth, physiology and phytotoxicity parameters of the plants. This is an important crop for human consumption with high nutritional value due to their low calorie and fat content, providing various vitamins and minerals, especially iron. These NPs were obtained by means of the sol-gel method and heat treatment; the resulting powder material was characterized using X-ray diffraction and scanning electron microscopy and the influence of these NPs on plants was measured by estimating the germination rate, monitoring morphological parameters and evaluating phytotoxicity. The photosynthetic activity of the spinach plants was estimated through the quantification of the Ratio of Oxygen Evolution (ROE) by the photoacoustic technique. Samples of TiO2 powder with particle size between 9 and 43 nm were used to quantify the germination rate, which served to determine a narrower size range between 7 and 26 nm in the experiments with Ag-TiO2 NPs; the presence of Ag in TiO2 powder samples was confirmed by energy-dispersive X-ray spectroscopy. The analysis of variance showed that the dependent variable (plant growth) could be affected by the evaluated factors (concentration and size) with significant differences. The statistical trend indicated that the application of the Ag-TiO2 NPs suspension of lowest concentration and smallest particle size could be a promoting agent of the growth and development of these plants. The inoculation with NPs of 8.3 nm size and lowest concentration was related to the highest average ROE value, 24.6 ± 0.2%, while the control group was 20.2 ± 0.2%. The positive effect of the Ag-TiO2 NPs treatment could be associated to the generation of reactive oxygen species, antimicrobial activity, increased biochemical attributes, enzymatic activity or improvements in water absorption.
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Affiliation(s)
- Fernando Gordillo-Delgado
- Applied Science Research Group for the Development of the Eco-Region (GICADE) Assigned to Interdisciplinary Institute of Sciences, University of Quindío, Armenia, Quindío, Colombia
- Program of Electronic Instrumentation Technology of Faculty of Basic Science and Technology, University of Quindío, Armenia, Colombia
- * E-mail:
| | - Jakeline Zuluaga-Acosta
- Applied Science Research Group for the Development of the Eco-Region (GICADE) Assigned to Interdisciplinary Institute of Sciences, University of Quindío, Armenia, Quindío, Colombia
| | - Gonzalo Restrepo-Guerrero
- Applied Science Research Group for the Development of the Eco-Region (GICADE) Assigned to Interdisciplinary Institute of Sciences, University of Quindío, Armenia, Quindío, Colombia
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4
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Luo M, Huang Y, Zhu M, Tang YN, Ren T, Ren J, Wang H, Li F. Properties of different natural organic matter influence the adsorption and aggregation behavior of TiO 2 nanoparticles. Journal of Saudi Chemical Society 2018. [DOI: 10.1016/j.jscs.2016.01.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Luo M, Qi X, Ren T, Huang Y, Keller AA, Wang H, Wu B, Jin H, Li F. Heteroaggregation of CeO2 and TiO2 engineered nanoparticles in the aqueous phase: Application of turbiscan stability index and fluorescence excitation-emission matrix (EEM) spectra. Colloids Surf A Physicochem Eng Asp 2017. [DOI: 10.1016/j.colsurfa.2017.08.014] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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6
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Dzinun H, Othman MHD, Ismail AF, Puteh MH, A. Rahman M, Jaafar J, Adrus N, Hashim NA. Antifouling behavior and separation performance of immobilized TiO2
in dual layer hollow fiber membranes. POLYM ENG SCI 2017. [DOI: 10.1002/pen.24753] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Hazlini Dzinun
- Advanced Membrane Technology Research Centre (AMTEC), Faculty of Chemical and Energy Engineering; Universiti Teknologi Malaysia; 81310 Skudai Johor Malaysia
| | - Mohd Hafiz Dzarfan Othman
- Advanced Membrane Technology Research Centre (AMTEC), Faculty of Chemical and Energy Engineering; Universiti Teknologi Malaysia; 81310 Skudai Johor Malaysia
| | - Ahmad F. Ismail
- Advanced Membrane Technology Research Centre (AMTEC), Faculty of Chemical and Energy Engineering; Universiti Teknologi Malaysia; 81310 Skudai Johor Malaysia
| | - Mohd Hafiz Puteh
- Department of Environmental Engineering, Faculty of Civil Engineering; Universiti Teknologi Malaysia; 81310 Skudai Johor Malaysia
| | - Mukhlis A. Rahman
- Advanced Membrane Technology Research Centre (AMTEC), Faculty of Chemical and Energy Engineering; Universiti Teknologi Malaysia; 81310 Skudai Johor Malaysia
| | - Juhana Jaafar
- Advanced Membrane Technology Research Centre (AMTEC), Faculty of Chemical and Energy Engineering; Universiti Teknologi Malaysia; 81310 Skudai Johor Malaysia
| | - Nadia Adrus
- Biopolymer Research Group, Department of Polymer Engineering, Faculty of Chemical and Energy Engineering; Universiti Teknologi Malaysia; 81310 Skudai Johor Malaysia
| | - Nur Awanis Hashim
- Department of Chemical Engineering, Faculty of Engineering; Universiti Malaya; 50603 Kuala Lumpur Malaysia
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Patchaiyappan A, Saran S, Devipriya SP. Recovery and reuse of TiO2 photocatalyst from aqueous suspension using plant based coagulant - A green approach. KOREAN J CHEM ENG 2016. [DOI: 10.1007/s11814-016-0059-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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8
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Wang H, Adeleye AS, Huang Y, Li F, Keller AA. Heteroaggregation of nanoparticles with biocolloids and geocolloids. Adv Colloid Interface Sci 2015; 226:24-36. [PMID: 26233495 DOI: 10.1016/j.cis.2015.07.002] [Citation(s) in RCA: 104] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2015] [Revised: 07/08/2015] [Accepted: 07/08/2015] [Indexed: 10/23/2022]
Abstract
The application of nanoparticles has raised concern over the safety of these materials to human health and the ecosystem. After release into an aquatic environment, nanoparticles are likely to experience heteroaggregation with biocolloids, geocolloids, natural organic matter (NOM) and other types of nanoparticles. Heteroaggregation is of vital importance for determining the fate and transport of nanoparticles in aqueous phase and sediments. In this article, we review the typical cases of heteroaggregation between nanoparticles and biocolloids and/or geocolloids, mechanisms, modeling, and important indicators used to determine heteroaggregation in aqueous phase. The major mechanisms of heteroaggregation include electric force, bridging, hydrogen bonding, and chemical bonding. The modeling of heteroaggregation typically considers DLVO, X-DLVO, and fractal dimension. The major indicators for studying heteroaggregation of nanoparticles include surface charge measurements, size measurements, observation of morphology of particles and aggregates, and heteroaggregation rate determination. In the end, we summarize the research challenges and perspective for the heteroaggregation of nanoparticles, such as the determination of αhetero values and heteroaggregation rates; more accurate analytical methods instead of DLS for heteroaggregation measurements; sensitive analytical techniques to measure low concentrations of nanoparticles in heteroaggregation systems; appropriate characterization of NOM at the molecular level to understand the structures and fractionation of NOM; effects of different types, concentrations, and fractions of NOM on the heteroaggregation of nanoparticles; the quantitative adsorption and desorption of NOM onto the surface of nanoparticles and heteroaggregates; and a better understanding of the fundamental mechanisms and modeling of heteroaggregation in natural water which is a complex system containing NOM, nanoparticles, biocolloids and geocolloids.
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Milowska K, Rybczyńska A, Mosiolek J, Durdyn J, Szewczyk EM, Katir N, Brahmi Y, Majoral JP, Bousmina M, Bryszewska M, El Kadib A. Biological Activity of Mesoporous Dendrimer-Coated Titanium Dioxide: Insight on the Role of the Surface-Interface Composition and the Framework Crystallinity. ACS Appl Mater Interfaces 2015; 7:19994-20003. [PMID: 26305597 DOI: 10.1021/acsami.5b04780] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Hitherto, the field of nanomedicine has been overwhelmingly dominated by the use of mesoporous organosilicas compared to their metal oxide congeners. Despite their remarkable reactivity, titanium oxide-based materials have been seldom evaluated and little knowledge has been gained with respect to their "structure-biological activity" relationship. Herein, a fruitful association of phosphorus dendrimers (both "ammonium-terminated" and "phosphonate-terminated") and titanium dioxide has been performed by means of the sol-gel process, resulting in mesoporous dendrimer-coated nanosized crystalline titanium dioxide. A similar organo-coating has been reproduced using single branch-mimicking dendrimers that allow isolation of an amorphous titanium dioxide. The impact of these materials on red blood cells was evaluated by studying cell hemolysis. Next, their cytotoxicity toward B14 Chinese fibroblasts and their antimicrobial activity were also investigated. Based on their variants (cationic versus anionic terminal groups and amorphous versus crystalline titanium dioxide phase), better understanding of the role of the surface-interface composition and the nature of the framework has been gained. No noticeable discrimination was observed for amorphous and crystalline material. In contrast, hemolysis and cytotoxicity were found to be sensitive to the nature of the interface composition, with the ammonium-terminated dendrimer-coated titanium dioxide being the most hemolytic and cytotoxic material. This surface-functionalization opens the door for creating a new synergistic machineries mechanism at the cellular level and seems promising for tailoring the biological activity of nanosized organic-inorganic hybrid materials.
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Affiliation(s)
- Katarzyna Milowska
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz , 141/143 Pomorska Street, 90-236 Lodz, Poland
| | - Aneta Rybczyńska
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz , 141/143 Pomorska Street, 90-236 Lodz, Poland
| | - Joanna Mosiolek
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz , 141/143 Pomorska Street, 90-236 Lodz, Poland
| | - Joanna Durdyn
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz , 141/143 Pomorska Street, 90-236 Lodz, Poland
| | - Eligia M Szewczyk
- Department of Pharmaceutical Microbiology and Microbiological Diagnostics, Medical University of Lodz , 137 Pomorska Street, 90-235 Lodz, Poland
| | - Nadia Katir
- Euromed Research Center, Engineering Division, Euro-Mediterranean University of Fes (UEMF), Fès-Shore , Route de Sidi Hrazem, 30070 Fès, Morocco
| | - Younes Brahmi
- Université Mohammed V Agdal, Faculté des Sciences, and MAScIR foundation, 10100 Rabat, Morocco
| | - Jean-Pierre Majoral
- Laboratoire de Chimie de Coordination (LCC) CNRS , 205 route de Narbonne, 31077 Toulouse, France
| | - Mosto Bousmina
- Euromed Research Center, Engineering Division, Euro-Mediterranean University of Fes (UEMF), Fès-Shore , Route de Sidi Hrazem, 30070 Fès, Morocco
| | - Maria Bryszewska
- Department of General Biophysics, Faculty of Biology and Environmental Protection, University of Lodz , 141/143 Pomorska Street, 90-236 Lodz, Poland
| | - Abdelkrim El Kadib
- Euromed Research Center, Engineering Division, Euro-Mediterranean University of Fes (UEMF), Fès-Shore , Route de Sidi Hrazem, 30070 Fès, Morocco
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Wang H, Dong YN, Zhu M, Li X, Keller AA, Wang T, Li F. Heteroaggregation of engineered nanoparticles and kaolin clays in aqueous environments. Water Res 2015; 80:130-138. [PMID: 26001279 DOI: 10.1016/j.watres.2015.05.023] [Citation(s) in RCA: 94] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Revised: 05/08/2015] [Accepted: 05/12/2015] [Indexed: 06/04/2023]
Abstract
The increasing and wide use of nanoparticles (NPs), including TiO2 and Ag NPs, have raised concerns due to their potential toxicity and environmental impacts. Kaolin is a very common mineral in aquatic systems, and there is a very high probability that nanoparticles (NPs) will interact with these clay minerals. We studied the effect of kaolin particles on the aggregation of NPs under different conditions, including the role of pH, ionic strength (IS), and humic acid (HA). We show that kaolin reduces the energy barrier and the Critical Coagulation Concentration (CCC) at pH 4. At pH 8, even though the energy barrier of the system without kaolin increases, kaolin promotes NP aggregation via heteroaggregation. When IS is equal to or greater than the CCC, on the one hand HA promotes aggregation of TiO2 NPs, but on the other hand HA decreases the rate of Ag NP aggregation because the existence of a surface coating may limit the adsorption of HA on these Ag NPs. In addition, the presence of HA increases the energy barrier and the CCC of the binary system (kaolin + NPs). Thus, the complex interactions of clay, NPs, IS, pH, and HA concentration determine the colloidal stability of the NPs. We find that kaolin is a potential coagulant for removal of NPs that behave like Ag and TiO2.
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Affiliation(s)
- Hongtao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China.
| | - Ya-nan Dong
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Miao Zhu
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Xiang Li
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Arturo A Keller
- Bren School of Environmental Science and Management, University of California, Santa Barbara, CA, 93106, United States
| | - Tao Wang
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
| | - Fengting Li
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, Ministry of Education, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China
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Dzinun H, Othman MHD, Ismail A, Puteh MH, Rahman MA, Jaafar J. Morphological study of co-extruded dual-layer hollow fiber membranes incorporated with different TiO2 loadings. J Memb Sci 2015. [DOI: 10.1016/j.memsci.2014.12.052] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Son J, Vavra J, Li Y, Seymour M, Forbes V. Interactions between suspension characteristics and physicochemical properties of silver and copper oxide nanoparticles: a case study for optimizing nanoparticle stock suspensions using a central composite design. Chemosphere 2015; 124:136-142. [PMID: 25550107 DOI: 10.1016/j.chemosphere.2014.12.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Revised: 12/05/2014] [Accepted: 12/06/2014] [Indexed: 06/04/2023]
Abstract
The preparation of a stable nanoparticle stock suspension is the first step in nanotoxicological studies, but how different preparation methods influence the physicochemical properties of nanoparticles in a solution, even in Milli-Q water, is often under-appreciated. In this study, a systematic approach using a central composite design (CCD) was employed to investigate the effects of sonication time and suspension concentration on the physicochemical properties (i.e. hydrodynamic diameter, zeta potential and ion dissolution) of silver (Ag) and copper oxide (CuO) nanoparticles (NPs) and to identify optimal conditions for suspension preparation in Milli-Q water; defined as giving the smallest particle sizes, highest suspension stability and lowest ion dissolution. Indeed, all the physicochemical properties of AgNPs and CuONPs varied dramatically depending on how the stock suspensions were prepared and differed profoundly between nanoparticle types, indicating the importance of suspension preparation. Moreover, the physicochemical properties of AgNPs and CuONPs, at least in simple media (Milli-Q water), behaved in predictable ways as a function of sonication time and suspension concentration, confirming the validity of our models. Overall, the approach allows systematic assessment of the influence of various factors on key properties of nanoparticle suspensions, which will facilitate optimization of the preparation of nanoparticle stock suspensions and improve the reproducibility of nanotoxicological results. We recommend that further attention be given to details of stock suspension preparation before conducting nanotoxicological studies as these can have an important influence on the behavior and subsequent toxicity of nanoparticles.
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Affiliation(s)
- Jino Son
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA.
| | - Janna Vavra
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Yusong Li
- Department of Civil Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA
| | - Megan Seymour
- Department of Civil Engineering, University of Nebraska-Lincoln, Lincoln, NE, USA; HDR, Inc., 8404 Indian Hills Dr, Omaha, NE 68114, USA
| | - Valery Forbes
- School of Biological Sciences, University of Nebraska-Lincoln, Lincoln, NE, USA
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Zhu M, Wang H, Keller AA, Wang T, Li F. The effect of humic acid on the aggregation of titanium dioxide nanoparticles under different pH and ionic strengths. Sci Total Environ 2014; 487:375-380. [PMID: 24793841 DOI: 10.1016/j.scitotenv.2014.04.036] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 04/07/2014] [Accepted: 04/08/2014] [Indexed: 06/03/2023]
Abstract
With the increasingly widespread use of titanium dioxide nanoparticles (TiO2 NPs), the particles' environmental impacts have attracted concern, making it necessary to understand the fate and transport of TiO2 NPs in aqueous media. In this study, we investigated TiO2 NP aggregation caused by the effects of humic acid (HA), ionic strength (IS) and different pH using dynamic light scattering (DLS) to monitor the size distribution of the TiO2 NPs continuously. It was determined that HA can influence the stability of TiO2 NPs through charge neutralization, steric hindrance and bridging effects. In the absence of IS, aggregation was promoted by adding HA only when the pH (pH=4) is less than the point of zero charge for the TiO2 NPs (pHPZC≈6) because HA reduces the zeta potential of the TiO2 NPs via charge neutralization. At pH=4 and when the concentration of HA is 94.5 μg/L, the zeta potential of TiO2 NPs is close to zero, and they reach an aggregation maximum. A higher concentration of HA results in more negatively charged TiO2 NP surfaces, which hinder their aggregation. When the pH is 5.8, HA enhances the negative zeta potential of the TiO2 NPs and increases their stability via electrostatic repulsion and steric hindrance. When the pH (pH=8) is greater than pHpzc, the zeta potential of the TiO2 NPs is high (~40 mV), and it barely changes with increasing HA concentration. Thus, the TiO2 NPs are notably stable, and their size does not grow at pH8. The increase in the critical coagulation concentration (CCC) of TiO2 NPs indicated that there is steric hindrance after the addition of HA. HA can enhance the coagulation of TiO2 NPs, primarily due to bridging effect. These findings are useful in understanding the size change of TiO2 NPs, as well as the removal of TiO2 NPs and HA from aqueous media.
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Affiliation(s)
- Miao Zhu
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Hongtao Wang
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China.
| | - Arturo A Keller
- Bren School of Environmental Science and Management, University of California, Santa Barbara, CA 93106, United States
| | - Tao Wang
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Fengting Li
- Key Laboratory of Yangtze River Water Environment, Ministry of Education, State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
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Hamedi-Shokrlu Y, Babadagli T. Stabilization of Nanometal Catalysts and Their Interaction with Oleic Phase in Porous Media during Enhanced Oil Recovery. Ind Eng Chem Res 2014. [DOI: 10.1021/ie4042033] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Yousef Hamedi-Shokrlu
- Department of Civil and
Environmental Engineering, School of Mining and Petroleum Engineering, University of Alberta, 3-112 Markin CNRL-NREF, Edmonton, Alberta, Canada T6G 2W2
| | - Tayfun Babadagli
- Department of Civil and
Environmental Engineering, School of Mining and Petroleum Engineering, University of Alberta, 3-112 Markin CNRL-NREF, Edmonton, Alberta, Canada T6G 2W2
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Wang H, Qi J, Keller AA, Zhu M, Li F. Effects of pH, ionic strength and humic acid on the removal of TiO2 nanoparticles from aqueous phase by coagulation. Colloids Surf A Physicochem Eng Asp 2014; 450:161-5. [DOI: 10.1016/j.colsurfa.2014.03.029] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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