scholarly journals Green Bio-Assisted Synthesis, Characterization and Biological Evaluation of Biocompatible ZnO NPs Synthesized from Different Tissues of Milk Thistle (Silybum marianum)

Nanomaterials ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 1171 ◽  
Author(s):  
Bilal Haider Abbasi ◽  
Muzamil Shah ◽  
Syed Salman Hashmi ◽  
Munazza Nazir ◽  
Sania Naz ◽  
...  
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Radical Scavenging ◽  
Biological Evaluation ◽  
Seed Extract ◽  
Wild Plant ◽  
Gravimetric Analysis ◽  
Silybum Marianum ◽  
Zno Nps ◽  
Wide Range ◽  
Different Tissues

The purpose of the current study was green synthesis of ZnO-nanoparticles (NPs) from different tissues of Silybum marianum (L.) Gaernt. (i.e., seeds, wild plant, in vitro derived plantlets and callus cultures) followed by extensive characterization and evaluation of their biological potency. ZnO-NPs thus synthesized were subjected to characterization using standard techniques such as XRD, FTIR and SEM. Thermal stability of synthesized NPs was also evaluated using thermo-gravimetric analysis. Highly stable crystalline NPs with size ranging between 30.8 and 46.0 nm were obtained from different tissues of S. marianum. These NPs have revealed a wide range of biological applications showing antioxidant, moderate α-amylase inhibitor, antibacterial and cytotoxic potencies. The highest antibacterial activity (20 ± 0.98 mm) was shown by seed extract-mediated ZnO NPs against Staphylococcus aureus (ATCC-6538). Seed extract-mediated ZnO NPs also showed the most potent antioxidant activity (27.7 ± 0.9 µgAAE/mg, 23.8 ± 0.7 µgAAE/mg and 12.7 ± 1.9% total antioxidant capacity (TAC), total reducing power (TRP) and DPPH-free radical scavenging assay (FRSA), respectively). All of the synthesized ZnO NPs also showed cytotoxic activity against the hepato-cellular carcinoma (HepG2) human cells. Interestingly, these ZnO NPs were also highly biocompatible, as evidenced by the brine shrimp lethality and human red blood cells hemolytic assays. Among all of the NPs synthesized and used, the effect of seed extract-mediated NPs was found to be most promising for future applications.

scholarly journals Lignin: A Biopolymer from Forestry Biomass for Biocomposites and 3D Printing

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3006 ◽  
Author(s):  
Mihaela Tanase-Opedal ◽  
Eduardo Espinosa ◽  
Alejandro Rodríguez ◽  
Gary Chinga-Carrasco
Keyword(s):  
3D Printing ◽  
Radical Scavenging Activity ◽  
Matrix Material ◽  
Thermo Gravimetric Analysis ◽  
Radical Scavenging ◽  
Fused Deposition Modelling ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Biobased Materials ◽  
Fused Deposition

Biopolymers from forestry biomass are promising for the sustainable development of new biobased materials. As such, lignin and fiber-based biocomposites are plausible renewable alternatives to petrochemical-based products. In this study, we have obtained lignin from Spruce biomass through a soda pulping process. The lignin was used for manufacturing biocomposite filaments containing 20% and 40% lignin and using polylactic acid (PLA) as matrix material. Dogbones for mechanical testing were 3D printed by fused deposition modelling. The lignin and the corresponding biocomposites were characterized in detail, including thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction analysis (XRD), antioxidant capacity, mechanical properties, and scanning electron microscopy (SEM). Although lignin led to a reduction of the tensile strength and modulus, the reduction could be counteracted to some extent by adjusting the 3D printing temperature. The results showed that lignin acted as a nucleating agent and thus led to further crystallization of PLA. The radical scavenging activity of the biocomposites increased to roughly 50% antioxidant potential/cm2, for the biocomposite containing 40 wt % lignin. The results demonstrate the potential of lignin as a component in biocomposite materials, which we show are adequate for 3D printing operations.

Temperature Stability Of Plasma Polymerized Antiadhesive Coatings

1998 ◽  
Vol 544 ◽  
Author(s):  
W. Michaeli ◽  
R. Dahlmann ◽  
I. Fonteiner
Keyword(s):  
Surface Tension ◽  
Photoelectron Spectroscopy ◽  
Thermo Gravimetric Analysis ◽  
Temperature Stability ◽  
Polymer Coatings ◽  
Gravimetric Analysis ◽  
Angle Measurements ◽  
Wide Range ◽  
Contact Angle Measurements ◽  
Thermal Stability Of

AbstractBy means of microwave-assisted plasma polymerization it is possible to deposit polymer coatings on different surfaces such as plastics or metals. The surface tension can be influenced in a wide range. However, many applications require a high thermal stability of such low surface tension layers. Therefore, the influence of variations of the process parameters on temperature stability of such layers is examined. The produced layers were studied regarding their chemical and physical characteristics under temperature influence by means of contact angle measurements, xray photoelectron spectroscopy (XPS), thermo gravimetric analysis (TGA) combined with Fouriertransformed infrared spectroscopy (FTIR). Fluorine containing monomers offer good perspectives. Up to temperatures of approx. 200°C the antiadhesivity of these coatings is adjustable to values close to those of poly(tetrafluoroethylene) (PTFE).

MECHANICAL PROPERTIES OF BAMBOO POWDER REINFORCED ETHYLENE PROPYLENE DIENE MONOMER (EPDM) COMPOSITES: EFFECT OF FILLER LOADING AND PARTICLE SIZE

2014 ◽  
Vol 6 (2) ◽  
pp. 1122-1134 ◽  
Author(s):  
Mokhtar Hemdan Abd El-Salam
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Particle Size ◽  
Internal Friction ◽  
Thermo Gravimetric Analysis ◽  
Filler Loading ◽  
Gravimetric Analysis ◽  
Wide Range ◽  
Bamboo Powder ◽  
Thermal Stability Of

Due to the light weight, high specific strength and non hazardous nature of bamboo fiber, it is preferred over synthetic fibers in composite materials for a wide range of applications such as automotive industry and including household sectors. As was noticed, little attention has been given to the effect of bamboo powder on the mechanical properties of rubber composites. Hence, an attempt has been made in this paper to the study the effect of loading and particle size of bamboo powder on the mechanical properties of EPDM composites. Thermo-gravimetric analysis (TGA) was carried out to study the thermal stability of composites. Results indicated that the thermal stability of EPDM was further improved with increasing in bamboo loading and decreasing in particle size. The stress- strain curves of the composites were studied and fitted according toOgden’s model. Mechanical parameters for the studied composites were improved with increasing bamboo loading. Besides, properties such as rupture stress, and internal friction were found to be maximum for composites containing certain content of bamboo powder, depending upon its particle size. Moreover, composites containing the smallest particle size of powder, at all levels of bamboo loading, showed mechanical properties superior to all other composites. From the dynamic mechanical measurements, the dynamic modulus, internal friction, and thermal diffusivity were calculated. The observed variations were explained in view of the role played by both the loading level and the particle size of bamboo powder. These findings were supported by scanning electron microscopy (SEM) micrographs.

Dewatering Studies on the Low Rank China Lignite Using N2, CO2 and Air

2015 ◽  
Author(s):  
Wei Chen ◽  
Yunlei Wang ◽  
Kalyan Annamalai ◽  
Jiafeng Sun ◽  
Zhimin Xie
Keyword(s):  
Release Rate ◽  
Thermo Gravimetric Analysis ◽  
Combined Cycle ◽  
Low Rank ◽  
Spontaneous Ignition ◽  
Gravimetric Analysis ◽  
Optimal Temperature ◽  
Temperature Range ◽  
Wide Range ◽  
Integrated Gasification

The integrated gasification and combined cycle (IGCC), uses low rank coal (higher moisture and volatile contents and lower heating value) as fuel for gasification (e.g Texaco gasifier of Tampa electric with low ash coal) and convert the solid fuel into synthetic gas mainly consisting of CO and H2. During the storage of fresh low rank but highly reactive coals near the IGCC plants, the coals undergo drying and low temperature atmospheric oxidation which raises the temperature, reduces the moisture and eventually causes spontaneous ignition if the temperature rises above about 800 °C in the coal piles for bituminous and 500 °C for lignite coals. Thus it is of interest to understand the dewatering mechanism of the low rank lignite by drying samples using N2, CO2 and air (which represents partial oxidation) as drying mediums. Fundamental experiments were performed on dewatering of coal samples using thermo-gravimetric analysis (TGA) with different particle sizes and drying mediums. A wide range of drying temperatures from 100 to 225 °C with a step of 25 °C was investigated at a residence time of about 30 minutes. There are no significant differences among moisture weight loss curves for the three drying mediums. It was found that the lignite lost only 5% mass at about 100 °C. With further increase in temperatures most of the mass loss occurred within the temperature range of 120 to 170 °C. The maximum moisture release rate occurred for the temperatures between 125 °C and 140 °C and hence serves as the optimal temperature range for removing the moisture. When drying temperature was below 140 °C, highest moisture release rate occurred in N2 environment while for CO2 environment, optimal temperature rose beyond 140 °C. The structure of the dewatered lignite samples were further investigated through Scanning Electron Microscopy (SEM) studies. When experiments were repeated in air, ignition occurred and corresponding ignition temperatures were obtained. The larger particles reveal lower ignition temperatures.

Dynamic Mechanical Analysis and Thermo-Gravimetric Analysis on Chopped Strand Mat Reinforced with Polyester Resin and Graphite Powder

2018 ◽  
Vol 1148 ◽  
pp. 48-60
Author(s):  
Pala Srinivas Reddy ◽  
T. Victor Babu ◽  
S. Santosh Kumar
Keyword(s):  
Dynamic Mechanical Analysis ◽  
Polyester Resin ◽  
Thermo Gravimetric Analysis ◽  
Graphite Powder ◽  
Mechanical Analysis ◽  
Gravimetric Analysis ◽  
Thermo Gravimetric ◽  
Dynamic Mechanical ◽  
Wide Range ◽  
Chopped Strand Mat

Fiber reinforced plastics have been widely used for manufacturing aircrafts and spacecrafts structural parts because of their high mechanical, physical properties. These are used in manufacturing of structural composites, printed circuit boards and in a wide range of special-purpose products which are included in medical field as well. Within reinforcing materials chopped strand mats are the most frequently used in structural constructions because of their properties such as viscoelasticity, strength and high thermal stability. The present work focuses on mechanical and thermal properties of chopped strand mat reinforced with polyester resin and filler as graphite powder (which has high melting point) in different weight fractions. Evaluation of material properties is tested using Thermo-Gravimetric Analysis and Dynamic Mechanical analysis at a standard temperature ranging between 20°C - 460°C and evaluated. The results show that inclusion of graphite powder in chopped strand mat exhibit better enhancement in results when compared.

scholarly journals Synthesis of CuO-NPS by simple wet chemical method using various dicarboxylic acid salts as precursors: Spectral characterization and in-vitro biological evaluation

2020 ◽  
Vol 34 (2) ◽  
pp. 323-334
Author(s):  
H. Rehman ◽  
Z. Ali ◽  
A. Qadir ◽  
M. H. Farooq ◽  
A. Shuaib ◽  
...  
Keyword(s):  
Dicarboxylic Acid ◽  
Chemical Reduction ◽  
Thermo Gravimetric Analysis ◽  
Dicarboxylic Acids ◽  
Biological Evaluation ◽  
Diffusion Method ◽  
Moderate Activity ◽  
Gravimetric Analysis ◽  
Zone Of Inhibition ◽  
Cuo Nps

In this study, a simple chemical reduction method was employed to synthesize CuO-NPs.  Various dicarboxylic acids were converted into Cu(II) salt of dicarboxylic acid which were used as precursors. NPs were produced by reducing precursors with NaBH4. Characteristics of synthesized NPs were investigated by using important analytical techniques including Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM). Developed NPs were investigated for their antibacterial activity against a range of bacterial strains by employing agar well diffusion method. CuO-NPs exhibited good to moderate activity against E-Coli, B. Subtilis and poor activity against K. pneumonia and Methicillin-resistant Staphylococcus aureus (MRSA). It was found that amongst all experienced compounds sample 2 showed good activity with minimum inhibition concentration (MIC) 10 µg/mL (zone of inhibition: 22± 0.12 mm) while sample 3 showed poor activity with MIC 40 µg/mL (zone of inhibition: 8.0 ± 0.18 mm).                     KEY WORDS: CuO-NPs, Dicarboxylic acids, Sodium borohydride, Antibacterial study   Bull. Chem. Soc. Ethiop. 2020, 34(2), 323-334 DOI: https://dx.doi.org/10.4314/bcse.v34i2.10

scholarly journals Synthesis, Characterization, Biological Evaluation and Molecular Docking Studies of Some Oxazinyl-Thiazolidinone Derivatives

2020 ◽  
Vol 32 (9) ◽  
pp. 2125-2129
Author(s):  
RAMARAJAN RAJALAKSHMI ◽  
RAJAVEL SANTHI ◽  
THANGARAJ ELAKKIYA
Keyword(s):  
Antioxidant Activity ◽  
Molecular Docking ◽  
Biological Activities ◽  
Radical Scavenging ◽  
Docking Studies ◽  
Biological Evaluation ◽  
Molecular Docking Studies ◽  
Ir Studies ◽  
Wide Range

A series of new 4-thiazolidinone derivatives of 2-(4-chlorophenyl)-3-(6-(thiophen-2-yl)-4-p-tolyl-4H-1,3-oxazin-2-yl)- thiazolidin-4-one (7h-m) are synthesized because of its wide range of biological activities.1H & 13C NMR, IR studies were applied for the elucidation of all the synthesized compounds. All the synthesized compounds have been tested for antidiabetic and antioxidant activity in vitro method against standard. The analogs 7h-m was evaluated for α-amylase and α-glucosidase inhibitory potential. The structures of all the compounds have been screened for antioxidant activity using DPPH radical scavenging assay, NO scavenging method. Molecular docking studies were accomplished in addition to understand the binding affinity of those compounds with PDBID 2HR7 which showed that the synthesized derivatives bind in the lively binding site of the target protein

Hydroxyapatite Nanocomposites for Biological Application

2013 ◽  
Vol 760 ◽  
pp. 39-42
Author(s):  
J. Kumar
Keyword(s):  
Polymer Concentration ◽  
Thermo Gravimetric Analysis ◽  
Controlled Drug Release ◽  
Medical Application ◽  
Ceramic Particle ◽  
Bone Diseases ◽  
Gravimetric Analysis ◽  
Wide Range ◽  
Ft Ir ◽  
Ir Study

Hydroxyapatite is a bioceramic which has a wide range of medical application for bone diseases. To enhance its usage, we have prepared ciprofloxacin loaded nanohydroxyapatite (HA) composite with a natural polymer, alginate, using wet chemical method at low temperature. The prepared composites were analyzed by various physicochemical methods. The results show that the nanoHA crystallites are well intact with the alginate macromolecules. For the composite system FT-IR study is done. The drug is pre-adsorbed onto the ceramic particle before the formation of composite. The thermal behavior of composite has been studied using thermo gravimetric analysis (TGA). This paper communicated the Influence of Polymer concentration on the Controlled drug release from hydroxyapatite Nanocomposites

Hydrogen Absorption Kinetics of Ti-Nb-Cr Alloys

2006 ◽  
Vol 510-511 ◽  
pp. 534-537
Author(s):  
Kyung Shin ◽  
Song Seok ◽  
Soon Young Kweon ◽  
Il Ho Kim ◽  
Young Geun Lee ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Hydrogen Absorption ◽  
Thermo Gravimetric Analysis ◽  
Solid Solution Phase ◽  
Gravimetric Analysis ◽  
Absorption Kinetics ◽  
Scanning Calorimetry ◽  
High Hydrogen ◽  
Wide Range

The Ti-Cr systems are known to consist of BCC solid solution, C36, C14, C15 Laves phase at high temperature. Among others, BCC solid solution phase has been reported to have a high hydrogen storage capacity. However, activation, wide range of hysteresis at hydrogenation/dehydrogenation, and degradation of hydrogen capacity due to hydriding/dehydriding cycles have to be improved for its application. In this study, for improving such a problem, we added on Nb. To obtain a target materials, Ti-1Nb-10Cr, Ti-3Nb-10Cr and Ti-5Nb-10Cr specimens were prepared by planetary ball mill. The milling process was carried out under nitrogen atmosphere. Specimens synthesized were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermo gravimetric analysis/differential scanning calorimetry(TG/DSC). In order to examine hydrogen absorption kinetics, Sievert's type automatic pressure-composition- isotherm (PCI) was performed at 293, 323 , 373 and 423K under 1, 5MPa hydrogen atmosphere.

Synthesis of Smart Mesoporous Materials

2003 ◽  
Vol 775 ◽  
Author(s):  
G.V.Rama Rao ◽  
Qiang Fu ◽  
Linnea K. Ista ◽  
Huifang Xu ◽  
S. Balamurugan ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Mesoporous Materials ◽  
Fluorescent Dyes ◽  
Thermo Gravimetric Analysis ◽  
Molecular Transport ◽  
Solute Diffusion ◽  
Gravimetric Analysis ◽  
Stimuli Responsive ◽  
Porous Network ◽  
Hybrid Mesoporous Materials

AbstractThis study details development of hybrid mesoporous materials in which molecular transport through mesopores can be precisely controlled and reversibly modulated. Mesoporous silica materials formed by surfactant templating were modified by surface initiated atom transfer radical polymerization of poly(N-isopropyl acrylamide) (PNIPAAm) a stimuli responsive polymer (SRP) within the porous network. Thermo gravimetric analysis and FTIR spectroscopy were used to confirm the presence of PNIPAAm on the silica surface. Nitrogen porosimetry, transmission electron microscopy and X-ray diffraction analyses confirmed that polymerization occurred uniformly within the porous network. Uptake and release of fluorescent dyes from the particles was monitored by spectrofluorimetry and scanning laser confocal microscopy. Results suggest that the presence of PNIPAAm, a SRP, in the porous network can be used to modulate the transport of aqueous solutes. At low temperature, (e.g., room temperature) the PNIPAAm is hydrated and extended and inhibits transport of analytes; at higher temperatures (e.g., 50°C) it is hydrophobic and is collapsed within the pore network, thus allowing solute diffusion into or out of the mesoporous silica. The transition form hydrophilic to hydrophobic state on polymer grafted mesoporous membranes was determined by contact angle measurements. This work has implications for the development of materials for the selective control of transport of molecular solutes in a variety of applications.

Sign in / Sign up

Export Citation Format

Share Document