A5023109356- Fullerene Chemistry and Applications
- Nanoparticles: synthesis and applications
- Carbon Nanotubes in Composites
- Graphene research and applications
- Graphene and Nanomaterials Applications
- Polymer Nanocomposite Synthesis and Irradiation
- Healthcare and Environmental Waste Management
- Microplastics and Plastic Pollution
- Coagulation and Flocculation Studies
- Astrophysics and Star Formation Studies
- Membrane Separation Technologies
- Mercury impact and mitigation studies
- Effects and risks of endocrine disrupting chemicals
- Diamond and Carbon-based Materials Research
- Advanced Theoretical and Applied Studies in Material Sciences and Geometry
- Water Treatment and Disinfection
- Fecal contamination and water quality
- Nanotechnology research and applications
- Computational Drug Discovery Methods
- Environmental remediation with nanomaterials
- Anesthesia and Neurotoxicity Research
- Pigment Synthesis and Properties
- TiO2 Photocatalysis and Solar Cells
- Electrostatics and Colloid Interactions
Duke University
2006-2014
Carnegie Mellon University
2010-2014
American Chemical Society
2014
Centre National de la Recherche Scientifique
2010
Centre de Recherche et d’Enseignement de Géosciences de l’Environnement
2008-2010
Rice University
2005-2009
University of Houston
2007-2009
California NanoSystems Institute
2009
University of Southern California
2006
University of California, Los Angeles
2006
Nanomaterial properties differ from those bulk materials of the same composition, allowing them to execute novel activities. A possible downside these capabilities is harmful interactions with biological systems, potential generate toxicity. An approach assess safety nanomaterials urgently required. We compared cellular effects ambient ultrafine particles manufactured titanium dioxide (TiO2), carbon black, fullerol, and polystyrene (PS) nanoparticles (NPs). The study was conducted in a...
Upon contact with water, under a variety of conditions, C60 spontaneously forms stable aggregate nanoscale dimensions (d = 25−500 nm), termed here "nano-C60". The color, hydrophobicity, and reactivity individual are substantially altered in this form. Herein, we provide conclusive lines evidence demonstrating that solution these aggregates crystalline order remain as underivatized throughout the formation/stabilization process can later be chemically reversed. Particle size affected by...
The production of reactive oxygen species (ROS) by aqueous suspensions fullerenes and nano-TiO2 (Degussa P25) was measured both in ultrapure water minimal Davis (MD) microbial growth medium. Fullerol (hydroxylated C60) produced singlet (1O2) 1O2 superoxide (O2−•) MD medium, but no hydroxyl radicals (OH•) were detected either case. PVP/C60 (C60 encapsulated with poly(N-vinylpyrrolidone)) more efficient than fullerol generating superoxide. However, two other aggregates C60, namely THF/nC60...
Nanomaterials are highly dynamic in biological and environmental media. A critical need for advancing health safety research nanomaterials is to identify physical chemical transformations that affect the nanomaterial properties their toxicity. Silver nanoparticles, one of most toxic well-studied nanomaterials, readily react with sulfide form Ag(0)/Ag2S core-shell particles. Here, we show sulfidation decreased silver nanoparticle toxicity four diverse types aquatic terrestrial eukaryotic...
In this study we report on the electrokinetic behavior of colloidal aggregates C60fullerenes (n-C60) produced through two different techniques: solvent exchange and extended mixing with water. first technique, used to produce materials in several recent toxicity transport studies, an organic such as tetrahydrofuran (THF) is dissolve C60 before The second technique more indicative conditions that might occur natural aquatic systems. Both types n-C60 were observed be negatively charged under a...
The physical−chemical behavior of the fullerene C60 in environmental and physiological media is interest for understanding potential transport, exposure, impacts these materials on organisms ecosystems. We consider role electrolyte composition concentration, effect organic macromolecules, mode preparation colloidal aggregates (nC60) deposition colloids a porous medium such as groundwater aquifer or water treatment filter. Results nC60 are qualitatively consistent with trends anticipated by...
The production of two reactive oxygen species through UV photosensitization polyhydroxylated fullerene (fullerol) is shown to enhance viral inactivation rates. both singlet and superoxide by fullerol in the presence light confirmed via unique methods: electron paramagnetic resonance reduction nitro blue tetrazolium. These findings build on previous results area impact microfauna. Results showed thatthe first-order MS2 bacteriophage rate nearly doubled due increased 125% as compared UVA...
Buckminsterfullerene (C60) is a known photosensitizer that produces reactive oxygen species (ROS) in the presence of light; however, its properties aqueous environments are still not well understood or modeled. In this study, production both singlet and superoxide by UV photosensitization colloidal aggregates C60 water was measured two distinct methods: electron paramagnetic resonance (EPR) with spin trapping compound, spectrophotometric detection reduced form tetrazolium compound XTT. Both...
The release of engineered nanomaterials (ENMs) into the biosphere will increase as industries find new and useful ways to utilize these materials. Scientists engineers are beginning assess material properties that determine fate, transport, effects ENMs; however, potential impacts released ENMs on organisms, ecosystems, human health remain largely unknown. This special collection four review papers technical identifies many key emerging knowledge gaps regarding interactions between...
Nonenveloped viruses are shown to be inactivated by singlet oxygen (1O2) produced in UVA photosensitized aqueous suspensions of a polyhydroxylated fullerene (C60(OH)22−24; fullerol, 40 μM). Experiments were performed with MS2, ssRNA bacteriophage, as well two dsDNA phages: PRD1, which has an internal lipid membrane, and T7, entirely lacks lipids. MS2 was highly susceptible inactivation, having rate constant 0.034 min−1 alone, increased 0.102 photoactivated fullerol. PRD1 T7 not alone but...
Theory is developed that relates the reactivity of nanoparticles to structure aggregates they may form in suspensions. This theory applied consider case reactive oxygen species (ROS) generation by photosensitization C(60) fullerenes. Variations aggregate and size appear account for an apparent paradox ROS as calculated using values photochemical kinetics fullerene (C(60)) its hydroxylated derivative, fullerol (C(60)(OH)(22-24)) assuming varies between compact fractal objects. A region...
C60 fullerene is a promising material because of its unique physiochemical properties. However, previous studies have reported that colloidal aggregates (nC60) produce toxicity in fish and human cell cultures. The preparation method nC60 raises questions as to whether the observed effects stem from fullerenes or organic solvents used during suspensions. In this paper, we set out elucidate mechanism by which tetrahydrofuran (THF) treatment enhance leads cytotoxicity mouse macrophage line. Our...
Ultraviolet (UV) irradiated polyhydroxylated fullerene (fullerol) nanomaterials are examined for their potential to degrade organic compounds via reactive oxygen species (ROS) mediated by a photosensitization process. Organic were selected sensitivity individual of (hydroxyl radical (·OH−) degradation salicylic acid (SA); singlet (1O2) 2-chlorophenol (2CP), and superoxide (O2·−) oxidation ethanol) monitored over time in aqueous suspensions fullerol aggregates. Only the 2CP showed significant...
An assessment of the potential risks posed by nanomaterials will require case-by-case evaluations processes controlling exposure and hazards such as toxicity. Factors that control fullerene transport transformation in aqueous environments their relationship to toxicity are discussed. Natural organic matter is observed either increase or decrease nanoparticle stability while trends reactive oxygen generation run counter proposed mechanisms possible
Numerous commercial products incorporate novel engineered nanomaterials such as gold, silica, zinc oxide, and fullerenes in complex matrices polymer composites, creams, textiles. Analytical methods for detecting are not well developed. Moreover, nanomaterial content properties of these typically unknown protected proprietary reasons. This study had two primary aims: detection C60 within face creams to establish a baseline concentration (the first time this has been performed) residual...
Environmental context The increasing use of engineered nanoparticles has led to concerns over potential exposure these novel materials. Predictions nanoparticle transport in the environment and risks could be simplified if all showed similar deposition behaviour when coated with macromolecules used production or encountered environment. We show, however, that each this study exhibited distinct even coated, hence risk assessments may need specifically tailored type nanoparticle. Abstract...
Carbon nanomaterials have been proposed as a basis for developing new technologies photocatalytic oxidation and disinfection, improved membrane processes, adsorbents, biofilm-resistant surfaces. This study details recent progress towards the development of these applications. We explored use carbon such fullerene C60, single-wall nanotubes (SWCNTs), multi-wall (MWCNTs) range including, degradation probe organic compound by in situ generation reactive oxygen species (ROS), strategies...