Papers by Humberto Riella
Journal of Applied Polymer Science, 2012
This work focuses on the comparison between the morphological, chemical, and electrical propertie... more This work focuses on the comparison between the morphological, chemical, and electrical properties of polyaniline doped with fluoridric and polyaniline, and doped with sulfuric acid. The FT-IR, XRD, and SEM/EDS results indicate that the use of hydrofluoric acid as doping agent does not provide meaningful changes in the crystalline and morphological structure of polyaniline. Although, the inclusion of F À type counter-ions from the doping process with HF provide more compact, denser, and with higher electrical conductivity polymeric matrices. V
... em Massas Cerâmicas HG Riella1, EU de C. Franjndlich2 e M. Durazzo2 1 Laboratório de Materiai... more ... em Massas Cerâmicas HG Riella1, EU de C. Franjndlich2 e M. Durazzo2 1 Laboratório de Materiais e Corrosão/EQA/UFSC, ... Retração (%)* 7,0 10,4 9,7 7,4 8,1 6,8 7,8 8,2 8,3 8,1 * medidas realizadas nos corpos de prova queimados a 1200 °C. ...
Nuclear Technology, 2013
ABSTRACT
Journal of Nanomaterials, 2018
A practical and economical method was developed for the production of an antibacterial cotton fab... more A practical and economical method was developed for the production of an antibacterial cotton fabric using zinc oxide nanostructures without the use of surface modifying agents. In this process, zinc nitrate hexahydrate and potassium hydroxide were used as starting materials and the reaction was performed at 50°C. The in situ growth of ZnO nanostructures on cotton fabric occurred in a single-stage process, and it started when the fabric samples were dipped for 1 min in the solution containing all the starting materials. The treated and untreated fabric samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and EDS. The cotton fabrics coated with ZnO nanostructures presented an antibacterial efficiency towards Pseudomonas aeruginosa, a gram-negative bacteria, and Staphylococcus aureus (S. aureus), a gram-positive bacteria.
Anais do XX Congresso Brasileiro de Engenharia Química, 2015
As tintas em pó representam hoje uma moderna opção para acabamentos superficiais, devido à elimin... more As tintas em pó representam hoje uma moderna opção para acabamentos superficiais, devido à eliminação do uso de solvente em sua formulação e processo e também ao seu alto rendimento, podendo substituir tintas líquidas nas aplicações em metal, vidro e madeira. O presente trabalho teve por objetivo estudar a influência do reticulante nas propriedades das tintas em pó do tipo poliéster. Para o estudo do reticulante, foram elaboradas amostras com reticulantes triglicidil isocianurato (TGIC) e tereftalato de diglicidila (TD), com e sem antioxidantes, de forma a entender suas influências por meio dos testes de resistência ao impacto, brilho, gel time, cor e intemperismo acelerado. Os resultados revelaram que o sistema Poliéster/TGIC apresentou resultados de resistência mecânica de 160 kg.cm, medição de brilho de 94,5 UB, e reatividade(gel time) de 103 s. Estes valores indicam resultados pouco superiores aos obtidos ao reticulante TD.
Anais do XX Congresso Brasileiro de Engenharia Química, 2015
Journal of Non-Crystalline Solids, 2007
The Li 2 Al 2 Si 3 O 10 glass-ceramics well crystallized and with a regular morphology was produc... more The Li 2 Al 2 Si 3 O 10 glass-ceramics well crystallized and with a regular morphology was produced starting from a mixture of Li 2 CO 3 , TiO 2 , Al 2 O 3 and coal bottom ash, after reducing the magnetite phase content. Its measured thermal expansion coefficient in the temperatures range from 25°C to 300°C is a (25-300) = À23.4 • 10 À7°CÀ1. This value is %18% smaller than that for the commercial lithium glass-ceramics (À23.4 • 10 À7°CÀ1 to 50 • 10 À7°CÀ1).
Anais do XX Congresso Brasileiro de Engenharia Química, 2015
Mining waste treatment technology selection. Disponível em:<http://www.itrcweb.org/miningwaste-gu... more Mining waste treatment technology selection. Disponível em:<http://www.itrcweb.org/miningwaste-guidance>. Acesso em: 25 maio 2016. Ozônio na recuperação de solos e recursos hídricos contaminados por mineração MAHMOUD, A.; FREIRE R. S. New methods for enhancing ozone efficiency on contaminated water treatment. Química Nova, v. 30, n. 1, p. 198-205. MEYER, S. T. O uso de cloro na desinfecção de águas, a formação de trihalometanos e os riscos potenciais à saúde pública. Cad. Saúde Públ., Rio de Janeiro, v. 10, n. 1, p. 99-110, jan./mar. 1994. MINE ENVIRONMENT NEUTRAL DRAINAGE − MEND. Acid rock drainage prediction manual. Disponível em: <http://mendnedem.org/category/uncategorized/>. Acesso em: 25 maio 2016. ORGANIZAÇÃO DAS NAÇÕES UNIDAS-ONU. Relatório mundial das Nações Unidas sobre desenvolvimento dos recursos hídricos: água para um mundo sustentável-Sumário Executivo.
Journal of Nuclear Materials, 2018
Image analysis and X-ray diffraction methods for phase quantification of UAl x phases. Mapping UA... more Image analysis and X-ray diffraction methods for phase quantification of UAl x phases. Mapping UAl x phase composition during target fabrication. Following UAl 2 transformation during rolling UAl x-Al dispersion targets.
Chemical Engineering Research and Design, 2019
This is a PDF file of an article that has undergone enhancements after acceptance, such as the ad... more This is a PDF file of an article that has undergone enhancements after acceptance, such as the addition of a cover page and metadata, and formatting for readability, but it is not yet the definitive version of record. This version will undergo additional copyediting, typesetting and review before it is published in its final form, but we are providing this version to give early visibility of the article. Please note that, during the production process, errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
Applied Sciences, 2017
Multicomponent silicate glasses and their corresponding glass-ceramic derivatives were prepared a... more Multicomponent silicate glasses and their corresponding glass-ceramic derivatives were prepared and tested for potential applications in dentistry. The glasses were produced via a melting-quenching process, ground and sieved to obtain fine-grained powders that were pressed in the form of small cylinders and thermally treated to obtain sintered glass-ceramic samples. X-ray diffraction investigations were carried out on the materials before and after sintering to detect the presence of crystalline phases. Thermal analyses, mechanical characterizations (assessment of bending strength, Young's modulus, Vickers hardness, fracture toughness), and in vitro bioactivity tests in simulated body fluid were performed. On the basis of the acquired results, different potential applications in the dental field were discussed for the proposed glass-ceramics. The use of such materials can be suggested for either restorative dentistry or dental implantology, mainly depending on their peculiar bioactive and mechanical properties. At the end of the work, the feasibility of a novel full-ceramic bilayered implant was explored and discussed. This implant, comprising a highly bioactive layer expected to promote osteointegration and another one mimicking the features of tooth enamel, can have an interesting potential for whole tooth substitution.
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Papers by Humberto Riella