Pineda, E.A.G.

• PhD
• Professor at State University of Maringá

Nanofibras de ZnO foram produzidas a partir de precursores à base de poli(álcool vinílico) (PVA) e acetato de zinco (AcZn) obtidos por eletrofiação, nas proporções mássicas de PVA/AcZn 1:1; 2:1 e 4:1, e posterior calcinação. Bandas características da ligação Zn-O e de transições eletrônicas do ZnO foram detectadas nos espectros de infravermelho (FT...

Rice husks (RH) are a known agricultural residue due to their abundance of silicon, that can be extracted for the production of materials with added high-value. Although part of RH can be converted into useful products, most of it is incinerated generating a large amount of toxic compounds, being of particular importance to find economically and en...

Al2O3-Zn x% NPs, with x = 0, 1, 3, 5 or 10 mol% Zn2+ were synthesized by a modified sol–gel method. The influence of the insertion of Zn2+ dopant on the crystal lattice, morphology, optical and cytotoxic properties of Al2O3 was investigated. Rietveld refinement applied to DRX data revealed that the oxides are constituted by four crystalline phases:...

Structural, morphological, optical, and photocatalytic properties of Mg-doped ZnO nano-semiconductors were investigated. All nanostructures exhibited spherical morphology with average crystallite diameters and band gap energy values between 47–54 nm and 3.00–3.05 eV, respectively. The increase in Mg ion contents (0.1–1.0 mol%) enhanced the photocat...

Chromium-doped \(\alpha\)-\(\hbox {Al}_{2}\hbox {O}_{3}\) powder was synthesized by a modified sol–gel method using poly(vinyl alcohol) aqueous solutions and metal nitrate precursors. The synthesis process is simple, is of low cost and produced final crystals with cubic shape as confirmed by X-ray diffraction. The morphology of the samples verified...

Nano-catalysts based on ZnO-Ca x% (with x = 0, 0.1, 0.3, 0.5, 0.7, and 1.0 mol % Ca ²⁺ ) were synthesized with a bio-friendly adaptation of the sol-gel method using gelatin as template. These materials were characterized by Fourier Transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Micro-Raman, transmission electron microscopy (TEM),...

Inorganic nanoparticles incorporation in polymer membranes for filtration processes has attracted the attention of researchers in order to improve in some ways their performance. In this work, AgNPs were synthesized "in situ" in cellulose acetate (CA) membrane by chemical reduction of a silver salt. The membranes were prepared by the nonsolvent ind...

This work reports the synthesization of nanoparticles cobalt oxide (Co3O4) with no secondary phase by a modified sol-gel method and its structural morphological and electrochemical characterizations. FTIR, XRD and Raman analysis showed the formation of spinel cobalt oxide with no secondary phase. TEM images revealed that an undefined morphology wit...

ZnO-Al x% nanoparticles (NPs), with x = 0, 1, 3, 5 or 10 mol% Al³⁺, were synthesized by a modified sol-gel method. The effects of Al³⁺ content on the structure, morphology and optical properties of Al-doped ZnO were investigated by powder X-ray diffraction (XRD), transmission electron microscopy (TEM), Raman spectroscopy, photoacoustic absorption s...

Hybrid materials based on cuprous oxide nanoparticles (Cu2ONPs) adsorbed on cotton fabric (CF) fibers were synthesized by in situ Cu²⁺ reduction. Ascorbic acid (AsA) or hydroxylamine (HA) was used as chemical reducing agent in the presence of polyvinylpyrrolidone (PVP) or lactose (Lac) as protective agent. UV-Vis diffuse reflectance spectra of the...

Fe 2 O 3 nanoparticles (as maghemite and hematite mixtures) were prepared using adapted sol-gel method from a polyvinylpyrrolidone (PVP) aqueous solution in various Fe ³⁺ : PVP monomer ratios. Analysis of X-ray diffraction was obtained to evaluate the crystalline state, average crystallite size, and composition of iron oxide phases. The morphology...

This work describes the synthesis of ferrite nanoparticles and the zinc and cobalt doping effect on tuning their magnetic properties. The zinc doping led to formation of a secondary crystalline phase (ZnO), which meant that the Zn and Co individual ions show different physical-chemical affinities for the two types of lattice sites. Zero-field cooli...

Mn-doped ZnO nanoparticles were successfully synthesized through the sol–gel technique. X-ray diffraction results showed that Mn doping did not disturb the hexagonal wurtzite structure of ZnO and no secondary phases were identified. Raman studies indicated the presence of defects in the form of oxygen vacancy clusters created due to Mn doping. Ferr...

Aminodextran (AMD) polymer was prepared via chemical grafting of hexamethylenediamine on oxidized dextran. Magnetic latex particles were successfully obtained by adsorption of positively charged AMD on negatively charged submicron magnetic emulsion. The adsorbed amount was found to be ranged from 20 to 1280 mg of AMD per gram of dried magnetic disp...

Films and fibers of PMMA/ZnO nanocomposites (100/0, 99/01, 97/03, 95/05, 90/10, and 85/15 wt.%) were produced by casting and electrospinning, respectively. Their structural, thermal, and optical properties were investigated by XRD, SEM, TGA, PAS, and PL. The incorporation of ZnO NPs reduced the diameter of PMMA fibers and the presence of beads. The...

Magnetic nanoparticles have been extensively studied, with special focus on their possible applications. Much effort has been done on developing new methods and synthesizing magnetic particles with improved properties. In this context, magnetic nanoparticles of spinel ferrites are of great interest, since their crystal chemistry and structure are r...

Hematite (?-Fe2O3) undergoes a first order spin reorientation transition called the Morin transition: upon cooling, the moments align antiferromagnetically along the rhombohedral axis, and the net magnetic moment goes to zero. Morin transition temperature is around to 260K in bulk materials and depends on the mean particle size. In this work, the M...

Poly(glycolide-co-lactide) (PLGA) nanospheres containing magnetic materials have been extensively studied because of its biomedical applications. Therefore, it is very important to know thermal properties of these materials in addition to other physical properties. Thermal degradation activation energy (Eα) of PLGA nanospheres with maghemite entrap...

This paper describes the synthesis and characterization of a hydrogel nanocomposite based on starch and Co-doped zinc ferrite nanoparticles (Co0.50Zn0.50Fe2O4) that underwent drug release changes in response to an external magnetic field. The material was prepared using vinylated starch together with N′,N′-dimethylacrylamide (DMAAm) and Co0.50Zn0.5...

Recently, significant research efforts have been devoted to the finding of efficient approaches in order to reduce the side effects of traditional cancer therapy and diagnosis. In this context, magnetic nanoparticles have attracted much attention because of their unique physical properties, magnetic susceptibility, biocompatibility, stability and m...

Resumo The use of heavy metals, especially in the industrial sector, has attracted attention for the impacts generated by the use of potentially toxic metals to the environment and public health. Adsorption is a process in which a substance (adsorbate) is physically or chemically attached to the surface of the adsorbent component and currently thi...

Numerous investigations are dedicated to the research and development of new polymer materials destined for innovation in pharmaceutical forms. The application of these technological resources has allowed the commercialization of new therapeutic systems for modified drug release. This investigation aimed to evaluate the association of modified chon...

New techniques for treating wastewater, particularly the removal or degradation of organic pollutants and heavy metals, among other pollutants, have been extensively studied. The use of nanostructured iron oxides as adsorbent and photocatalyst for the removal of these contaminants has proved a promising approach, not only because of their high trea...

It is becoming progressively more understandable that different phytochemicals isolated from edible plants interfere with specific stages of carcinogenesis. Cancer cells have evolved hallmark mechanisms to escape from death. Concordant with this approach, there is a disruption of spatiotemproal behaviour of signaling cascades in cancer cells, which...

Iron oxide nanoparticles (ION) have been studied for essential applications, like detection of biological constituents (virus, bacterials, cell, nucleic acids, protein, enzyme, etc.), magnetic bioseparation and clinic therapy and diagnosis (such as MRI magnetic fluid and hyperthermia). In this work, γ-Fe2O3 has been synthetized by a adapted sol-gel...

Iron oxide nanoparticles (ION) have been studied for essential applications, like detection of biological constituents (virus, bacterials, cell, nucleic acids, protein, enzyme, etc.), magnetic bioseparation and clinic therapy and diagnosis (such as MRI magnetic fluid and hyperthermia). In this work, gamma-Fe2O3 has been synthetized by a adapted sol...

Pure and Co-doped ZnO nanoparticles were synthesized with different cobalt levels (1–10 mol%) via adapted sol–gel method using water as solvent and characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy and photoacoustic absorption spectroscopy. The results showed that all the samples have hexagonal wurtzite struct...

Fe2O3 nanoparticles with sizes ranging from 15 to 53 nm were synthesized by a modified sol-gel method. Maghemite particles as well as particles with admixture of maghemite and hematite were obtained and characterized by XRD, FTIR, UV-Vis photoacoustic and Mössbauer spectroscopy, TEM, and magnetic measurements. The size and hematite/maghemite ratio...

Time-dependent films, augmented with prebiotics, offer potential strategy for colon-specific controlled drug release. In this study, we produced films containing levan (L) and Aminoalkyl Methacrylate Copolymer RS (ER). Free films of ER combined with levan were produced by the casting process and characterized by the mobility of the polymeric matrix...

Time-dependent films, augmented with prebiotics, offer potential strategy for colon-specific controlled drug release. In this study, we produced films containing levan (L) and Aminoalkyl Methacrylate Copolymer RS (ER). Free films of ER combined with levan were produced by the casting process and characterized by the mobility of the polymeric matrix...

Ni0.04Zn0.96O and Fe0.03Zn0.97O with average diameter of 23 and 19 nm, respectively, have been synthesized by a modified sal-gel method to be used in the preparation of (100 - x)/x poly(vinyl alcohol)/oxide nanocomposite films, with x = 0, 1, 3 and 5 (in wt.%). A 125 W-Hg vapor lamp with emission above 254 nmwas used to irradiate PVA/Ni0.04Zn0.96O...

Magnetic nanoparticles have been proposed as interesting tools for biomedical purposes. One of their promising utilization is the MRI in which magnetic substances like maghemite are used in a nanometric size and encapsulated within locally biodegradable nanoparticles. In this work, maghemite has been obtained by a modified sol-gel method and encaps...

Levan was used as agent in the synthesis of new colon-specific polymeric matrix together with Eudragit ® FS 30 D. Eudragit ® FS 30 D films incorporated with levan were made by casting process and characterized to: water vapour transmission, sweeling index, differential scanning calorimetry and thermogravimetric. The levan increased the films permea...

The aim of this research was to evaluate levan as agent in the synthesis of the new polymeric matrix together with Eudragit FS30D. Eudragit FS30D films incorporated with levan were made for casting process and characterized to: water vapour transmission, sweeling index, differential scanning calorimetry (DSC) and thermogravimetric (TGA). The levan...

The most stable form of iron oxide is Hematite (α-Fe2O3), which has interesting electronic, catalytic, and magnetic properties showing size dependent characteristics. At room temperature, Hematite is weakly ferromagnetic with a rhombohedral corundum structure. Upon cooling, the structure undergoes a first order spin reorientation, in which the net...

The acetone-soluble lignin fraction (ASLF) of sugar cane bagasse, from a sugar and alcohol factory residue, was obtained after extraction with formic acid and used to prepare blends with poly(vinyl acetate) (PVAc) by casting. PVAc and ASLF/PVAc blends were irradiated with ultraviolet light (Hg lamp). Blend formation and the irradiation effects were...

ZnO nanoparticles with average diameter of 25 nm were synthesized by a modified sol-gel method and used in the preparation of (in wt.%) (100-x) poly(vinyl alcohol) (PVA)/x ZnO nanocomposite films, with x = 0, 1, 2,3, 4, and 5. The PVA/ZnO films were exposed to UV radiation for 96 h and their thermal, morphological, and spectroscopic properties were...

Kraft lignin coming from a paper industry was purified and the modified fraction by formic acid (FKL) was isolated to be used as an inhibitor of UV-photodegradation in polyamide 6 (PA6) films. Samples containing up to 1.00% of FKL in mass were prepared by casting using formic acid as solvent. The effects of UV light irradiation on these films (Hg l...

Nickel oxide (NiO), iron (III) oxide (Fe2O3), and mixed oxide (Ni0.04Zn0.96O and Fe0.03Zn0.97O) nanoparticles were synthesized by modified sol–gel method. The nanoparticle structural and morphological properties were investigated by infrared spectroscopy (FTIR), X-ray powder diffractometry (XRD), scanning electron microscopy (SEM), and Mössbauer sp...

In this work were developed free films from Surelease®, additives α-GOS (alfa-glucooligosaccharide) and/or Tween® 80 in aqueous solution. It was obtained by Teflon plates "casting" process. The free films were characterized by thermal analysis (DSC and TGA), infrared spectroscopy (FTIR-ATR) and scanning electron microscopy (SEM). DSC and TG analysi...

The physicochemical and antimicrobial properties of starch-chitosan films incorporated with oregano essential oil (OEO) have been investigated. The antimicrobial effects of starch-chitosan-OEO films against Bacillus cereus, Escherichia coli, Salmonella enteritidis, and Staphylococcus aureus were determined by the disk inhibition zone method. The fi...

ZnO, CuO, and Cu0.05Zn0.95O nanoparticles have been prepared by a sol–gel method using poly(vinyl alcohol) aqueous solutions and metal nitrate precursors. The precursor powders were analyzed by thermogravimetry (TG) and differential scanning calorimetry (DSC). X-ray powder diffractometry (XRD), infrared spectroscopy (FTIR), and scanning electron mi...

The galactomannan from Mimosa scabrella Bentham was extracted on a pilot plant scale and dried either by vacuum oven (GVO) or by spray-drier (GSD) to evaluate the effect of the drying technique on the powder quality and its applicability as excipient in solid dosage forms. The analysis by high performance size exclusion chromatography (HPSEC) coupl...

A high dosage of albendazole (ABZ) is required for treating systemic helminthe infections because of its low solubility. Aiming at increasing ABZ solubility, complexation with beta-cyclodextrin (β-CD) using aqueous and acetic acid solutions as ABZ solubilizer was studied. In aqueous β-CD, complexation increased solubility 53.4 times, giving a compl...

The adsorption kinetics and equilibrium of methylene blue (MB) onto reticulated formiclignin (RFL) from sugar cane bagasse was studied. The adsorption process is pH, temperature and ionicstrength (μ) dependent and obeys the Langmuir model. Conditions for higher adsorption rate andcapacity were determined. The faster adsorption (12 hours) and higher...

The adsorption kinetics and equilibrium of methylene blue (MB) onto reticulated formic lignin (RFL) from sugar cane bagasse was studied. The adsorption process is pH, temperature and ionic strength (µ) dependent and obeys the Langmuir model. Conditions for higher adsorption rate and capacity were determined. The faster adsorption (12 hours) and hig...

Cellulose from a cotton residue was isolated, characterized and used for benzylcellulose preparation. A comparative study was done using a commercial cellulose. IR, DSC and TGA were used to characterize celluloses and benzylcelluloses. Experimental data showed that the cotton residue cellulose has a different thermal behavior compared to other cell...

A kraft lignin derivative (KLD) obtained by reaction with p-aminobenzoic acid/phthalic anhydride was blended with poly(vinyl alcohol) (PVA) by solution casting from DMSO. PVA and PVA/KLD films were exposed to ultraviolet radiation (24, 48, and 96 h) and analyzed by thermogravimetry (TG), differential scanning calorimetry (DSC), infrared spectroscop...

The thermal history of freeze-dried mixtures of composite powders containing ZnO–matrix and (CH3COO)2Cu·H2O (copper(II) acetate monohydrate) was undertaken by thermal analysis (TA) coupled to thermoelectrical analysis (TEA). Experiments were carried out on compacted samples, under non-isothermal conditions, in air, up to 350°C, by measuring the ele...

A kraft lignin derivative (KLD) obtained by reaction with p-aminobenzoic acid/phthalic anhydride, was blended with poly(vinyl alcohol) (PVA) by solution casting from DMSO. PVA and PVA/KLD films were exposed to ultraviolet radiation (Hg lamp, 96h) and analyzed by thermogravimetry (TG) in inert and oxidative atmosphere. Typical multi-step decompositi...

Because of its biodegradability several natural polymers, such as polysaccharides, have been proposed as appropriate excipients for the development of controlled drug delivery systems for oral administration. Chondroitin sulfate (ChS), a highly water-soluble mucopolysaccharide, was crosslinked with trisodium trimetaphosphate (TMFS) in order to achi...

Lignin and poly(vinylalcohol) (PVA) solutions were separately prepared and then mixed in appropriate ratios, to yield the films after solvent (DMSO) evaporation. Two lignin samples were used: kraft lignin (KL) and acetone soluble fraction of kraft lignin (AKL). Different carbonyl and hydroxyl contents were detected by 1 HNMR and by FTIR for KL and...

Summary The aspartame is an artificial sweetener was discovered accidentally in the United States by J. M. Schlatter in 1965. In this work the kinetic of the thermal decomposition of sweetener, containing aspartame as sweetening agent, by means isothermal TG method was studied. The comparison of thermogravimetric data to the reference profiles of s...

Lignin and poly(vinylalcohol) (PVA) solutions were separately prepared and then mixed in appropriate ratios, to yield the films after solvent (DMSO) evaporation. Two lignin samples were used: kraft lignin (KL) and acetone soluble fraction of kraft lignin (AKL). Different carbonyl and hydroxyl contents were detected by (HNMR)-H-1 and by FTIR for KL...

The uses of polysaccharides are attracting a lot of attention for development of new specific drug delivery systems. These polymers are found in abundance, are inexpensive, are available in a variety of structure with varied properties and can be easily modified chemically; in addition, they are specific biodegradable. The cross linking of polysacc...

Ethylcellulose (EC) has been widely used as a coating material for controlled release systems. Some oligo-polysaccharides such as inulin (IN), guar gum (GG) and their derivatives have been proposed as biodegradable materials for site-specific releases. The objective of this study was to characterise free films composed of EC associated to IN or GG...

Microcrystalline cellulose (MCC) is a very important product in pharmaceutic, food, cosmetic and other industries. In this work, MCC was prepared from soybean husk, produced in large quantities in soybean oil processing industries. It was characterized through various techniques (scanning electron microscopy (SEM), infrared spectroscopy (FTIR), the...

Alkaline lignin was isolated from sugar cane bagasse for polyblends preparation with three poly (vinyl alcohol) (PVAl) samples (80, 87 and 98% hydrolyzed). Blends preparation was carried out by thorough manual grinding the solid polymer powders, and for one system a comparison was made with blends prepared without grinding. The resulting blends wer...

The effects of temperature, pH and ionic strength on adsorption of Cd(II) and Pb(II) onto carboxymethylated lignin from sugar cane bagasse have been studied. Adsorption equilibrium data obtained using the batch technique were fitted to the Langmuir model. A factorial design showed that the most important variables are temperature and ionic strength...

The separation of cupric ion from aqueous solution by adsorption onto sugar cane bagasse, cellulose and oxidized cellulose from sugar cane bagasse was studied. The adsorption equilibrium was attained in 8h at room temperature. The adsorption was found to fit the Langmuir and Scatchard isotherms and the parameter n (maximum adsorbent capacity) and b...

The separation of cupric ions from aqueous solution by adsorption onto modified corncobs (hemicellulose-free) was studied. The adsorption process was found to take ∼ 15 minutes to attain equilibrium in experiments with continuous agitation at 35°C. The process was found to be pH-dependent, with increasing adsorption as pH increases up to 6.00. Ther...

A fração solúvel em acetona da lignina fórmica (FLBC) foi extraída do bagaço de cana de açúcar. Foram preparados filmes de PVAc e FLBC/PVAc a 5, 10 e 15% em massa de FLBC, por casting. Os filmes foram irradiados com luz UV durante 96 horas, com lâmpada de vapor de mercúrio. Estes foram analisados por DSC e TGA . Os filmes de PVAc mostraram uma perd...

Estudou-se a pirólise dinâmica, e a influência da adição de carbonato de potássio às amostras de papel jornal no meio reacional para obtenção de carvão. As amostras puras e com carbonato de potássio foram pirolisadas utilizando termogravimetria dinâmica em diferentes condições para um estudo estatístico e determinação de um modelo para as respostas...