Lizandro Manzato - Academia.edu (original) (raw)

Papers by Lizandro Manzato

Colloids and Surfaces A: Physicochemical and Engineering Aspects

Supplemental Material, Slide1 for Solubilization, characterization, and protein coupling analysis... more Supplemental Material, Slide1 for Solubilization, characterization, and protein coupling analysis to multiwalled carbon nanotubes by Juliane Glória, Walter Brito, Ariamna Gandarilla, Duniesky Larrude, Jacqueline Carlos, Felipe Araújo, Maria Edilene Almeida, Lizandro Manzato and Luis André Morais Mariúba in High Performance Polymers

This work aimed to characterize a by-product of the water treatment process, aiming to insert it ... more This work aimed to characterize a by-product of the water treatment process, aiming to insert it into the productive chain of construction. Such by-product was generated in a water treatment plant (WTP), which performs the capture of raw water from the Negro River and, eventually, from the Solimões River. To adapt the water from these sources to the Brazilian standards potable water, a series of physical-chemical processes are carried out at WTP, which lead to the generation of waste called as WTP sludge. Aiming to identify possible technological applications for this by-product, a pertinent bibliographical research was carried out. That way, it was verified that WTP sludge needs pretreatment prior to use. Like this, in order to make the studied WTP sludge an adequate raw material, the same was submitted to drying, grinding and calcination. Before and after such procedures, the sludge characteristics was determined by means of X-Ray Fluorescence (XRF), X-Ray Diffraction (XRD), Therm...

Journal of Environmental Chemical Engineering, 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.

Ultrasonics Sonochemistry, 2019

In this study we report the synthesis of silver tungstate microcrystals (-Ag2WO4) by sonochemist... more In this study we report the synthesis of silver tungstate microcrystals (-Ag2WO4) by sonochemistry method (SC) at 65 °C and sonochemistry followed by conventional hydrothermal (SC+HC) for 1, 6 and 12 hours, at 140 °C. The structural characterization by XRD confirms the alpha phase of the orthorhombic structure and the space group , for all synthesized 2 microcrystals. All the actives modes identified at the Raman spectroscopy were characteristic of alpha phase. The optical band gap by UV-Vis spectroscopy using the diffuse reflectance were 2.98, 3.0, 2.99 and 2.96 eV, for the microcrystals SC, SC+HC-1h, SC+HC-6h and SC+HC-12h, respectively. FE-SEM images show the rod-like microcrystals, however, exhibiting the plane surface (101) only for the synthesized microcrystals with the assistance of the hydrothermal method (SC+HC-1h, SC+HC-6h and SC+HC-12h). The antimicrobial potential was confirmed for all -Ag 2 WO 4 microcrystals synthesized. However, the SC + HC-12h microcrystals were more susceptible in the bacterial and fungal inhibition, with MIC values for microorganisms C. albicans, T. rubrum, MRSA e EHEC, 0.2-0.5, 4-9, 250 and 31.25 g mL-1 , respectively.

Fibers and Polymers, 2018

Cellulose was isolated from plant material for the first time in 1839 by the French chemist Ansel... more Cellulose was isolated from plant material for the first time in 1839 by the French chemist Anselme Payen. In recent years, due to the need in reduce the world's environmental problems, there has been an increase in studies related to the physical and chemical factors of cellulose. It is important to emphasize that experiments and studies with a cellulose occur individually, because of the variation in the amount of cellulose and the extraction method that differs from plant to plant. In the present study, we determined the optimal conditions for cellulose extraction of jute fiber, using the response surface method. The Box-Behnken Design (BBD) was used statistically evaluate the ratio effects of sodium hydroxide (NaOH) and sodium hypochlorite (NaClO), temperature and extraction time in the process used. The analysis of the results showed a significant variable in the linear and quadratic terms of the temperature and also a significant level of interaction in the effect between the variables of temperature and time. Besides this, the BBD used for the analysis of the extraction yield, resulted in a polynomial regression of second order, in complete agreement with experimental results, with R 2 =0.9627 (p<0.05). The optimal condition was obtained in a ratio of 1.3 at 45 o C for 2 h. Under the best possible conditions, the obtained experimental value is in accordance with the value predicted by the model, thus indicating a model combination and success to optimize the extraction conditions of the jute fiber pulp in the response surface methodology.

Journal of Molecular Structure, 2017

Emeraldine-salt polyaniline form (ES-PANI) was chemically synthesized using hydrochloric acid and... more Emeraldine-salt polyaniline form (ES-PANI) was chemically synthesized using hydrochloric acid and subjected to heat treatment for 1 h at 50, 100, 200 and 300 °C. X-ray Diffraction (XRD), Le Bail method, Infrared-transform Fourier Spectroscopy (FTIR), Small-angle X-ray Scattering (SAXS), Scanning Electron Microscopy (SEM) and Electrical Conductivity measurements were used to evaluate the influence of heat treatment on the semi-crystalline structure of PANI. The heat treatment has resulted in a progressive decrease of crystallinity from 50 to 22%. A crosslinking process during heat treatment was observed by FTIR at 200 °C, revealing some chemical changes in molecular structure of PANI such as elimination of HCl on the imino groups and the simultaneous chlorination of the aromatic rings. Le Bail method showed that unheated ES-PANI is strongly dependent on the molecular size of the counter ion, so the unit cell volume needed to be increased for their accommodation in polymer structure. The refined parameters suggested decomposition from tetrameric to dimeric-folded chains, accompanied by a decrease in the crystallite anisotropy and average size and shape, which reduced from 36 Å to 16 Å and acquired oblate shape. The pair-distance distribution function (p(r)) curves suggested particles tending from oblate to prolate form over heat treatment. Well-defined nanofibers were observed in unheated ES-PANI, which decreased and lost progressively their initial morphology over heat treatment. Electrical conductivity showed a decreasing of about 90% due to the loss of emeraldine sequences and to the removal of chloride ions.

Vii Connepi Congresso Norte Nordeste De Pesquisa E Inovacao, Aug 29, 2012

No presente trabalho, investigamos o efeito da moagem de alta energia (MAE) na estrutura dos cris... more No presente trabalho, investigamos o efeito da moagem de alta energia (MAE) na estrutura dos cristais de estanho (Sn). O material precursor foi o estanho de alta pureza na forma de po com tamanho medio de cristalito em torno de 236 nm. Este material foi moido em um micromoinho planetario em intervalos de duas horas ate completar 28 h. As amostras preparadas foram entao examinadas por difracao de raios-X (DRX) e analisadas pelo metodo de Rietveld para refinamento estrutural que permitiu o calculo do tamanho medio de cristalito assim como microdeformacoes da rede cristalina. Resultados a partir destas analises mostraram que apos 26 h o tamanho de cristalito fica estavel em torno de 46 nm.

Journal of Materials Research, 2013

ABSTRACT The effects of stearic acid on the high-energy ball milling of tin powder have been inve... more ABSTRACT The effects of stearic acid on the high-energy ball milling of tin powder have been investigated. The mean crystallite sizes, microstrain, and phase transformations were examined using different techniques like x-ray diffraction (XRD), Rietveld refinement method, and differential scanning calorimetry (DSC). After 28 h of milling, the Rietveld analysis showed the stabilization of Sn mean crystallite sizes at around 50 nm. Due to the presence of oxygen in stearic acid, the milling process gradually produced an amorphous Sn oxide phase. The DSC thermogram of the sample milled for 28 h showed two exothermic peaks separated by an endothermic peak. Based on the DSC measurements, two samples were annealed at 240 and 350 °C for 20 min. The annealing at 240 °C confirmed the presence of an amorphous phase which crystallized in nanostructured tetragonal SnO phase. The annealing at 350 °C revealed the nucleation of nanostructured tetragonal SnO2 phase.

Matéria (Rio de Janeiro), 2018

RESUMO Este trabalho teve como objetivo caracterizar um subproduto do processo de tratamento de á... more RESUMO Este trabalho teve como objetivo caracterizar um subproduto do processo de tratamento de água, visando inseri-lo na cadeia produtiva da construção civil. Tal subproduto foi gerado em uma estação de tratamento de água (ETA), que realiza a captação de água bruta do Rio Negro e, eventualmente, do Rio Solimões. Para adequar a água desses mananciais aos padrões de potabilidade brasileiros, executa-se na ETA uma série de processos físico-químicos, os quais acarretam a geração do resíduo designado lodo de ETA. Visando identificar possíveis aplicações tecnológicas para o referido resíduo, fez-se uma pesquisa bibliográfica pertinente. Desse modo, constatou-se que esse tipo de subproduto necessita de beneficiamento prévio à utilização. Sendo assim, para tornar o lodo de ETA estudado uma matéria-prima apropriada, submeteu-se o mesmo a procedimentos de secagem, moagem e calcinação. Antes e após tais procedimentos, suas características foram determinadas por meio de Fluorescência de Raios...

Fibers and Polymers, 2021

Amazon region found abundant vegetal fibers with diversified properties to the application. Tucum... more Amazon region found abundant vegetal fibers with diversified properties to the application. Tucum and malva fibers regularly obtained in this region were applied as reinforcement in the polymeric biomatrix and as a substitute for synthetic materials. Castor oil was used as the polyol to prepare the polyurethane biomatrix (PU). Amazon fibers were incorporated in this biomatrix using high proportions (30, 50, and 70 wt.%; 30 mm length), TPU (tucum polyurethane composite), and MPU (malva polyurethane composite). This study valorized regional materials and substituted synthetic products by renewable source materials. The fibers’ characterization results showed a high cellulose percentage, promoting high crystallinity values by XRD (X-ray diffraction) results (67.5 % for malva and 60.0 % for tucum). SEM (Scanning Electron Microscopy) images revealed the arrangement/thickness of the fibers, as well as the composite morphology. Thermolysis and mechanical properties investigate the composit...

Os catalisadores acidos normalmente empregados na sintese de biodiesel apresentam diversas desvan... more Os catalisadores acidos normalmente empregados na sintese de biodiesel apresentam diversas desvantagens, tais como corrosao e difi culdade de reutilizacao. Assim, este trabalho teve como objetivo a sintese e caracterizacao do catalisador solido acido SO42−/TiO2/metacaulim pelo metodo de impregnacao, onde o TiO2 foi preparado pelo metodo sol-gel e diretamente suportado no metacaulim do Amazonas com posterior sulfatacao. O catalisador obtido (STMK) foi caracterizado pelas tecnicas de fl uorescencia (FRX) e espectroscopia de infravermelho (FTIRATR). A atividade catalitica do STMK foi avaliada pela esterifi cacao do acido oleico com metanol, apresentando conversao superior a 96% nas seguintes condicoes reacionais: razao molar metanol:acido 20:1, 105°C, 5% m/m de catalisador em relacao a massa do acido e 1 h de reacao. O alto potencial do STMK como catalisador para a producao de biodiesel foi demonstrado.

Research, Society and Development, 2021

Araucaria (Araucaria angustifolia) is a tree species found in the Southeast and South of Brazil. ... more Araucaria (Araucaria angustifolia) is a tree species found in the Southeast and South of Brazil. It is also known as Brazilian pine, presenting fruits of high acceptance. However, its processing generates by-products that are little used. Thus, this work aimed to extract and characterize the cellulose obtained from the pinion husk, as well as to evaluate the contents of ash, lignin, cellulose and α-cellulose in its composition. The raw material and the extracted cellulose were characterized by X-ray fluorescence analysis (XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). As for the contents of chemical composition detected, the husks showed 1.6% ash, 7% extractives, 34% lignin and 55% cellulose, being 46% α-cellulose and 9% hemicellulose. It was observed by XRD that the removal of amorphous materials resulted in a gain of crystallinity (from 19 to 33%). Proving the efficiency of the extraction, the characterization of...

The Journal of Physical Chemistry C

Cerâmica

Resumo Neste estudo, pelo método de geopolimerização, produziu-se uma cerâmica alternativa utiliz... more Resumo Neste estudo, pelo método de geopolimerização, produziu-se uma cerâmica alternativa utilizando como matéria-prima lodo de estação de tratamento de água (ETA). Primeiramente, esse resíduo foi seco, moído, peneirado e calcinado, sendo caracterizado antes e após tais procedimentos. Com o lodo de ETA devidamente calcinado, a 750 °C por 4 h, produziu-se um geopolímero. Esse material, em estado endurecido, é semelhante a certos tipos de cerâmicas. Os corpos de prova geopoliméricos produzidos foram curados à temperatura ambiente durante 1, 7 e 28 dias. Após a cura, foram caracterizados por meio de difração de raios X, fluorescência de raios X, microscopia eletrônica de varredura e resistência à compressão axial. Curado à temperatura ambiente, o geopolímero atingiu, em média, 20 MPa em apenas 1 dia de idade e 60 MPa aos 28 dias. Constatou-se, portanto, que lodos de ETA podem ser utilizados no desenvolvimento de materiais cerâmicos de elevada resistência mecânica. Com base nos resulta...

Journal of Molecular Structure

Abstract The recycling of plant wasted materials into useful products represents a green alternat... more Abstract The recycling of plant wasted materials into useful products represents a green alternative to prevent environmental problems. Tucuma palm fruit ( Astrocaryum aculeatum Meyer) is widely used in Amazon region for food and crafts. Due to the large amount of wasted Tucuma’s endocarp, this work proposes a new approach for extraction of cellulose and its structural characterization. X-ray Diffraction (XRD), Rietveld Refinement, Scanning Electron Microscopy (SEM), Infrared-transform Fourier Spectroscopy (FTIR) and Thermal Analysis (TG/DSC) have been used for characterization of the extracted cellulose. XRD patterns of the in natura tucuma’s endocarp has showed a natural crystalline content embedded in a non-crystalline matrix. Nanocrystals of cellulose have been observed in the XRD pattern of the extracted cellulose, showing a good agreement with type II. Rietveld refinement allowed the cell parameters obtainment ( a = 8.43(1) A, b = 9.50(1) A, c = 9.39(3) A and γ = 118.43(4)°). Apparent average crystallite size and microstrain were, respectively, 20.0 A and 0.1%. Two different methods were applied for estimative of crystallinity percentage. In the first method the height ratio between the intensity of the crystalline peak and the total intensity after the subtraction of the non-crystalline content was applied, leading to 48.5%. The second approach was performed using the amorphous area and the total area of the (1 1 0) peak from the experimental diffractogram, leading to 31.5%. The difference in crystallinity percentage concerning these two used approaches may be explained due to the first method does not consider the broad peaks resulted from nanocrystals diffraction. FTIR spectroscopy has evidenced a cellulose type II structure. SEM images showed micrometric sized fibers with ranged thicknesses. However, a new morphology of spherical nanostructures was observed on the type II matrix fibers. Thermal analysis suggests that the extracted cellulose have low thermal stability, which resulted from poor ordered, packed chains. A large exothermic band was found in DSC curve and associated to the release of energy from the amorphous phase degradation. Thus, this work successfully extracted cellulose from tucuma’s endocarp and allowed its structural, morphological and thermal characterization.

Materials Chemistry and Physics, 2016

Abstract A nanostructured SnSe 2 phase was successfully produced by mechanical alloying. The infl... more Abstract A nanostructured SnSe 2 phase was successfully produced by mechanical alloying. The influence of defect centers on the structural, optical and photoacoustic properties of the alloy was investigated by annealing the as-milled SnSe 2 powder. From optical absorbance and photoacoustic absorption measurements, the energy band gap, E g , and the thermal diffusivity, α, values were determined for as-milled and annealed samples. The thermal conductivity values for the as-milled and annealed samples were estimated by using the α values obtained from the photoacoustic measurements, the density values obtained from the Rietveld refinement of the X-ray diffraction patterns and the specific heat value for the bulk SnSe 2 phase. These values were used to estimate the dimensionless figure of merit ZT . It was evidenced that the ZT parameter of the as-milled nanostructured SnSe 2 sample is almost twice larger than the ZT of the annealed sample.