scholarly journals Propolis and Organosilanes as Innovative Hybrid Modifiers in Wood-Based Polymer Composites

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 464
Author(s):  
Majka Odalanowska ◽  
Magdalena Woźniak ◽  
Izabela Ratajczak ◽  
Daria Zielińska ◽  
Grzegorz Cofta ◽  
...  
Keyword(s):  
Trichoderma Viride ◽  
Antimicrobial Properties ◽  
Absorption Spectrometry ◽  
Strength Properties ◽  
Tetraethyl Orthosilicate ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Propolis Extract ◽  
Polypropylene Matrix

The article presents characteristics of wood/polypropylene composites, where the wood was treated with propolis extract (EEP) and innovative propolis-silane formulations. Special interest in propolis for wood impregnation is due to its antimicrobial properties. One propolis-silane formulation (EEP-TEOS/VTMOS) consisted of EEP, tetraethyl orthosilicate (TEOS), and vinyltrimethoxysilane (VTMOS), while the other (EEP-TEOS/OTEOS) contained EEP, tetraethyl orthosilicate (TEOS), and octyltriethoxysilane (OTEOS). The treated wood fillers were characterized by Fourier transform infrared spectroscopy (FTIR), atomic absorption spectrometry (AAS), and X-ray diffraction (XRD), while the composites were investigated using differential scanning calorimetry (DSC), X-ray diffraction (XRD), and optical microscopy. The wood treated with EEP and propolis-silane formulations showed resistance against moulds, including Aspergillus niger, Chaetomium globosum, and Trichoderma viride. The chemical analyses confirmed presence of silanes and constituents of propolis in wood structure. In addition, treatment of wood with the propolis-silane formulations produced significant changes in nucleating abilities of wood in the polypropylene matrix, which was confirmed by an increase in crystallization temperature and crystal conversion, as well as a decrease in half-time of crystallization parameters compared to the untreated polymer matrix. In all the composites, the formation of a transcrystalline layer was observed, with the greatest rate recorded for the composite with the filler treated with EEP-TEOS/OTEOS. Moreover, impregnation of wood with propolis-silane formulations resulted in a considerable improvement of strength properties in the produced composites. A dependence was found between changes in the polymorphic structures of the polypropylene matrix and strength properties of composite materials. It needs to be stressed that to date literature sources have not reported on treatment of wood fillers using bifunctional modifiers providing a simultaneous effect of compatibility in the polymer-filler system or any protective effect against fungi.

scholarly journals Electrochemical deposition of coatings of highly entropic alloys from non-aqueous solutions

2016 ◽  
Vol 60 (1) ◽  
pp. 6-12 ◽  
Author(s):  
V. Jeníček ◽  
L. Diblíková ◽  
M. Bláhová
Keyword(s):  
Aqueous Solutions ◽  
Electrochemical Deposition ◽  
Absorption Spectrometry ◽  
New Materials ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Electrochemical Coating ◽  
First Results ◽  
Combination Of Methods

Abstract The paper deals with electrochemical deposition of coatings of highly entropic alloys. These relatively new materials have been recently intensively studied. The paper describes the first results of electrochemical coating with highly entropic alloys by deposition from non-aqueous solutions. An electrochemical device was designed and coatings were deposited. The coatings were characterised with electronic microscopy scanning, atomic absorption spectrometry and X-ray diffraction methods and the combination of methods of thermic analysis of differential scanning calorimetry and thermogravimetry.

scholarly journals Production of Nanocellulose by Enzymatic Treatment for Application in Polymer Composites

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2124
Author(s):  
Daria Zielińska ◽  
Kinga Szentner ◽  
Agnieszka Waśkiewicz ◽  
Sławomir Borysiak
Keyword(s):  
Polymer Composites ◽  
High Performance ◽  
Structural Parameters ◽  
Supermolecular Structure ◽  
Strength Properties ◽  
Cellulolytic Enzymes ◽  
Enzymatic Reactions ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray

In the last few years, the scientific community around the world has devoted a lot of attention to the search for the best methods of obtaining nanocellulose. In this work, nanocellulose was obtained in enzymatic reactions with strictly defined dispersion and structural parameters in order to use it as a filler for polymers. The controlled enzymatic hydrolysis of the polysaccharide was carried out in the presence of cellulolytic enzymes from microscopic fungi—Trichoderma reesei and Aspergillus sp. It has been shown that the efficiency of bioconversion of cellulose material depends on the type of enzymes used. The use of a complex of cellulases obtained from a fungus of the genus Trichoderma turned out to be an effective method of obtaining cellulose of nanometric dimensions with a very low polydispersity. The effect of cellulose enzymatic reactions was assessed using the technique of high-performance liquid chromatography coupled with a refractometric detector, X-ray diffraction, dynamic light scattering and Fourier transform infrared spectroscopy. In the second stage, polypropylene composites with nanometric cellulose were obtained by extrusion and injection. It was found by means of X-ray diffraction, hot stage optical microscopy and differential scanning calorimetry that nanocellulose had a significant effect on the supermolecular structure, nucleation activity and the course of phase transitions of the obtained polymer nanocomposites. Moreover, the obtained nanocomposites are characterized by very good strength properties. This paper describes for the first time that the obtained cellulose nanofillers with defined parameters can be used for the production of polymer composites with a strictly defined polymorphic structure, which in turn may influence future decision making about obtaining materials with controllable properties, e.g., high flexibility, enabling the thermoforming process of packaging.

scholarly journals Silver nanoparticles nucleated in NaOH-treated halloysite: a potential antimicrobial material

2021 ◽  
Vol 12 ◽  
pp. 798-807
Author(s):  
Yuri B Matos ◽  
Rodrigo S Romanus ◽  
Mattheus Torquato ◽  
Edgar H de Souza ◽  
Rodrigo L Villanova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Antimicrobial Properties ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Scanning Calorimetry ◽  
Medical Treatments ◽  
X Ray ◽  
E Coli ◽  
Transmission Electron

Despite all recent advances in medical treatments, infectious diseases remain dangerous. This has led to intensive scientific research on materials with antimicrobial properties. Silver nanoparticles (Ag-NPs) are a well-established solution in this area. The present work studied the nucleation of silver on halloysite substrates modified by chemical treatment with NaOH. The resulting stabilized Ag-NPs were characterized by X-ray diffraction, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. The nucleation was characterized by thermogravimetric analysis and differential scanning calorimetry. The antimicrobial properties of the Ag-NPs were investigated against E. coli and S. aureus. The potential of the Ag-NPs for industrial application was tested by dispersing them into low-density polyethylene. The importance of the chemical affinity between matrix and additive was tested through coating the Ag-NPs with dodecanethiol, a non-polar surfactant. The resulting composites were characterized by scanning electron microscopy and in terms of surface antimicrobial activity. The results demonstrate that the Ag-NPs synthesized in this work are indeed antimicrobial, and that it is possible to imbue a polymeric matrix with the antimicrobial properties of Ag-NPs.

scholarly journals Silver nanoparticles nucleated in NaOH treated halloysite: a potential antimicrobial material.

2021 ◽  
Author(s):  
Yuri B Matos ◽  
Rodrigo S Romanus ◽  
Mattheus Torquato ◽  
Edgar H de Souza ◽  
Rodrigo L Villanova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Antimicrobial Properties ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Scanning Calorimetry ◽  
Medical Treatments ◽  
X Ray ◽  
E Coli ◽  
Transmission Electron

Despite all recent advances in medical treatments, infectious diseases remain dangerous. This scenario has led to intense scientific research on materials with antimicrobial properties. Silver nanoparticles (Ag-NPs) are a well established solution in this area. The present work studied the nucleation of silver in halloysite substrates (HNT) modified by a NaOH chemical treatment. The resulting stabilized Ag-NPs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive x-ray spectroscopy (EDS). The nucleation was characterized by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Ag-NPs antimicrobial properties were investigated against \textit{E. coli} and \textit{S. aureus}. The potential of Ag-NPs for industrial application was tested by dispersing them into low density polyethylene (LDPE). The importance of the chemical affinity between matrix and additive was tested coating Ag-NPs with dodecanethiol, a non-polar surfactant. The resulting composites were characterized by scanning electron microscopy (SEM) and in terms of surface antimicrobial activity. The results demonstrate that Ag-NPs synthesized in this work are indeed antimicrobial, and that it is possible to imbue a polymeric matrix with the Ag-NPs antimicrobial properties.

Studies on the Preparation, Characterization and Solubility of -Cyclodextrin-Roxythromycin Inclusion Complexes

2009 ◽  
Vol 2 (2) ◽  
pp. 523-530
Author(s):  
D. Nagasamy Venkatesh ◽  
S. Karthick ◽  
M. Umesh ◽  
G. Vivek ◽  
R.M. Valliappan ◽  
...  
Keyword(s):  
Dissolution Rate ◽  
Inclusion Complexes ◽  
Phase Solubility ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ir Studies ◽  
Poorly Soluble ◽  
Poorly Soluble Drug

Roxythromycin/ β-cyclodextrin (Roxy/ β-CD) dispersions were prepared with a view to study the influence of β-CD on the solubility and dissolution rate of this poorly soluble drug. Phase-solubility profile indicated that the solubility of roxythromycin was significantly increased in the presence of β-cyclodextrin and was classified as AL-type, indicating the 1:1 stoichiometric inclusion complexes. Physical characterization of the prepared systems was carried out by differential scanning calorimetry (DSC), X-ray diffraction studies (XRD) and IR studies. Solid state characterization of the drug β-CD binary system using XRD, FTIR and DSC revealed distinct loss of drug crystallinity in the formulation, ostensibly accounting for enhancement of dissolution rate.

scholarly journals A review of nanotechnology with an emphasis on Nanoplex

2015 ◽  
Vol 51 (2) ◽  
pp. 255-263
Author(s):  
Rupali Nanasaheb Kadam ◽  
Raosaheb Sopanrao Shendge ◽  
Vishal Vijay Pande
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Drug Loading ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Conventional Drug ◽  
Anionic Drugs ◽  
Oppositely Charged ◽  
The Brain

<p>The use of nanotechnology based on the development and fabrication of nanostructures is one approach that has been employed to overcome the challenges involved with conventional drug delivery systems. Formulating Nanoplex is the new trend in nanotechnology. A nanoplex is a complex formed by a drug nanoparticle with an oppositely charged polyelectrolyte. Both cationic and anionic drugs form complexes with oppositely charged polyelectrolytes. Compared with other nanostructures, the yield of Nanoplex is greater and the complexation efficiency is better. Nanoplex are also easier to prepare. Nanoplex formulation is characterized through the production yield, complexation efficiency, drug loading, particle size and zeta potential using scanning electron microscopy, differential scanning calorimetry, X-ray diffraction and dialysis studies. Nanoplex have wide-ranging applications in different fields such as cancer therapy, gene drug delivery, drug delivery to the brain and protein and peptide drug delivery.</p>

scholarly journals Diethylstilbestrol Modifies the Structure of Model Membranes and Is Localized Close to the First Carbons of the Fatty Acyl Chains

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 220
Author(s):  
Alessio Ausili ◽  
Inés Rodríguez-González ◽  
Alejandro Torrecillas ◽  
José A. Teruel ◽  
Juan C. Gómez-Fernández
Keyword(s):  
Membrane Surface ◽  
Water Layer ◽  
Fatty Acyl ◽  
31P Nmr Spectroscopy ◽  
Relaxation Rates ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Acyl Chains ◽  
Dynamics Simulations

The synthetic estrogen diethylstilbestrol (DES) is used to treat metastatic carcinomas and prostate cancer. We studied its interaction with membranes and its localization to understand its mechanism of action and side-effects. We used differential scanning calorimetry (DSC) showing that DES fluidized the membrane and has poor solubility in DMPC (1,2-dimyristoyl-sn-glycero-3-phosphocholine) in the fluid state. Using small-angle X-ray diffraction (SAXD), it was observed that DES increased the thickness of the water layer between phospholipid membranes, indicating effects on the membrane surface. DSC, X-ray diffraction, and 31P-NMR spectroscopy were used to study the effect of DES on the Lα-to-HII phase transition, and it was observed that negative curvature of the membrane is promoted by DES, and this effect may be significant to understand its action on membrane enzymes. Using the 1H-NOESY-NMR-MAS technique, cross-relaxation rates for different protons of DES with POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) protons were calculated, suggesting that the most likely location of DES in the membrane is with the main axis parallel to the surface and close to the first carbons of the fatty acyl chains of POPC. Molecular dynamics simulations were in close agreements with the experimental results regarding the location of DES in phospholipids bilayers.

scholarly journals Effects of Sintering Temperature on Densification, Microstructure and Mechanical Properties of Al-Based Alloy by High-Velocity Compaction

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 218
Author(s):  
Xianjie Yuan ◽  
Xuanhui Qu ◽  
Haiqing Yin ◽  
Zaiqiang Feng ◽  
Mingqi Tang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Velocity ◽  
Sintered Density ◽  
Sintering Temperature ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
High Velocity Compaction ◽  
Sintered Temperature

This present work investigates the effects of sintering temperature on densification, mechanical properties and microstructure of Al-based alloy pressed by high-velocity compaction. The green samples were heated under the flow of high pure (99.99 wt%) N2. The heating rate was 4 °C/min before 315 °C. For reducing the residual stress, the samples were isothermally held for one h. Then, the specimens were respectively heated at the rate of 10 °C/min to the temperature between 540 °C and 700 °C, held for one h, and then furnace-cooled to the room temperature. Results indicate that when the sintered temperature was 640 °C, both the sintered density and mechanical properties was optimum. Differential Scanning Calorimetry, X-ray diffraction of sintered samples, Scanning Electron Microscopy, Energy Dispersive Spectroscopy, and Transmission Electron Microscope were used to analyse the microstructure and phases.

scholarly journals Extraction of Boron from Ludwigite Ore: Mechanism of Soda-Ash Roasting of Lizardite and Szaibelyite

Minerals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 533 ◽  
Author(s):  
Xin Zhang ◽  
Guanghui Li ◽  
Jinxiang You ◽  
Jian Wang ◽  
Jun Luo ◽  
...  
Keyword(s):  
Sodium Carbonate ◽  
Energy Dispersive Spectrometer ◽  
Low Grade ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Selective Activation ◽  
X Ray ◽  
Shed Light ◽  
Soda Ash ◽  
Scanning Electron

Ludwigite ore is a typical low-grade boron ore accounting for 58.5% boron resource of China, which is mainly composed of magnetite, lizardite and szaibelyite. During soda-ash roasting of ludwigite ore, the presence of lizardite hinders the selective activation of boron. In this work, lizardite and szaibelyite were prepared and their soda-ash roasting behaviors were investigated using thermogravimetric-differential scanning calorimetry (TG-DSC), X-ray diffraction (XRD), and scanning electron microscope and energy dispersive spectrometer (SEM-EDS) analyses, in order to shed light on the soda-ash activation of boron within ludwigite ore. Thermodynamics of Na2CO3-MgSiO3-Mg2SiO4-Mg2B2O5 via FactSage show that the formation of Na2MgSiO4 was preferential for the reaction between Na2CO3 and MgSiO3/Mg2SiO4. While, regarding the reaction between Na2CO3 and Mg2B2O5, the formation of NaBO2 was foremost. Raising temperature was beneficial for the soda-ash roasting of lizardite and szaibelyite. At a temperature lower than the melting of sodium carbonate (851 °C), the soda-ash roasting of szaibelyite was faster than that of lizardite. Moreover, the melting of sodium carbonate accelerated the reaction between lizardite with sodium carbonate.

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