Hybrid Low-Dimensional Carbon Allotropes Formed in Gas Phase

Graphene, carbon nanotubes (CNTs) and fullerenes are the basic set of low-dimensional carbon allotropes. The latter two arise from the former by selective removal and addition of carbon atoms. Nevertheless, given their morphological disparities, the production of each is typically devised from entirely different starting points. Here, it is demonstrated that all three allotropes can nucleate from (pseudo-)spherical, nanometer-sized transition metal clusters in a gas-suspension when the chemical conditions are favorable. The experimental results indicate that graphitic carbon embryos nucleate on the catalyst particles and sometimes transform into 2D graphene flakes through chain polymerization of carbon fragments forming in the surround gas atmosphere. It is further shown that hydrogenation reactions play an essential role by stabilizing the emerging flakes by mitigating the pentagon and heptagon defects that lead into evolution of fulleroids. Ab initio molecular dynamics simulations show that the ratio of hydrogen to carbon in the reaction is a key growth parameter. Since structural formation takes place in a gas-suspension, graphene accompanied by fullerenes and single-walled CNTs can be deposited on any surface at ambient temperature with arbitrary layer thicknesses. This provides a direct route for the production and deposition of graphene-based hybrid thin films for various applications.Peer reviewe

Engineered Nanomaterials for Emerging Contaminant Removal from Wastewater

Emerging contaminants (ECs), mainly organic compounds, are pollutants of growing concern. Several important ones are pharmaceuticals and personal care products, wood preservatives, hormones, plasticizers, pesticides, laundry detergents, surfactants, disinfectants, food additives, and flame retardants among other organic compounds recently found in natural wastewater stream that are generated by both human and also industrial activities. Most of ECs lacks of standard regulations; nevertheless, they could drive to lethal effects on aquatic life but also in human even at small concentrations. The conventional water treatment plants are not able to efficiently remove or even degrade these pollutants, so another effective and expensive tertiary treatment method is required. It is known that adsorption is a very useful method to remove different kinds of contaminants being then a promising method for the removal of EC due to its simplicity on operating design, low initial cost for implementation, and high efficiency. The current review resumes the technological approaches regarding adsorption process used for the treatment of ECs.Fil: Ollier Primiano, Romina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Villanueva, María Emilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Química Analítica y Fisicoquímica. Cátedra de Química Analítica Instrumental; Argentina. Universidad Nacional de Luján. Departamento de Ciencias Básicas; ArgentinaFil: Copello, Guillermo Javier. Universidad de Buenos Aires. Facultad de Farmacia y Bioquimica. Instituto de Química y Metabolismo del Fármaco; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Alvarez, Vera Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Sanchez, Laura Mabel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin