scholarly journals Preparation of Hydrogel/Silver Nanohybrids Mediated by Tunable-Size Silver Nanoparticles for Potential Antibacterial Applications

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 716 ◽  
Author(s):  
Yeray Rodríguez Nuñez ◽  
Ricardo Castro ◽  
Felipe Arenas ◽  
Zoraya López-Cabaña ◽  
Gustavo Carreño ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Polymer Network ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Crosslinking Degree ◽  
Transmission Electron ◽  
Hydrogel Network ◽  
Hydrogel Matrix ◽  
Ft Ir ◽  
Scanning Electron

In this study, a versatile synthesis of silver nanoparticles of well-defined size by using hydrogels as a template and stabilizer of nanoparticle size is reported. The prepared hydrogels are based on polyvinyl alcohol and maleic acid as crosslinker agents. Three hydrogels with the same nature were synthesized, however, the crosslinking degree was varied. The silver nanoparticles were synthesized into each prepared hydrogel matrix achieving three significant, different-sized nanoparticles that were spherical in shape with a narrow size distribution. It is likely that the polymer network stabilized the nanoparticles. It was determined that the hydrogel network structure can control the size and shape of the nanoparticles. The hydrogel/silver nanohybrids were characterized by swelling degree, Thermal Gravimetric Analysis (TGA), Fourier Transform Infrared (FT-IR), Scanning Electron Microscopy (SEM) and Transmission Electron Microscope (TEM). Antibacterial activity against Staphylococcus aureus was evaluated, confirming antimicrobial action of the encapsulated silver nanoparticles into the hydrogels.

scholarly journals Structural, Thermal, Morphological, Adsorption and Catalytic Properties of Poly(BPDAH-co-ODA/PPDA)-Ag/V2O5 Nanocomposites

2019 ◽  
Vol 15 (1) ◽  
pp. 155-174
Author(s):  
Govindharajan Sribala ◽  
Balakrishnan Meenarathi ◽  
Ramasamy Anbarasan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
1H Nmr ◽  
Catalytic Reduction ◽  
Aromatic Proton ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Ft Ir ◽  
Scanning Electron

Thermally stable polyimides (PIs) were prepared by condensation technique at 160 ºC for 5 hours in N-methylpyrrolidone (NMP) medium under N2 atmosphere both in the presence and absence of metal (Ag) and metaloxide (MO) (V2O5) nanoparticles (NPs). The synthesized polymers are characterized by Fourier Transform Infra Red (FT-IR) spectroscopy, 1H Nuclear Magnetic Resonance (1H NMR) spectroscopy, Differential Scanning Calorimetry (DSC), Thermal Gravimetric Analysis (TGA), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy with Energy Dispersive X-Ray (FE-SEM and EDX). The FT-IR spectrum showed a peak at 1786 cm-1 corresponding to the C=O stretching of dianhydride. The aromatic proton signals appeared between 6.7 and 7.5 ppm in the 1H-NMR spectrum of the resultant PIs. The oxydianiline (ODA) based PI with Ag NP loaded system exhibited the highest Tg value. The apparent rate constant values for the adsorption and catalytic reduction of p-nitrophenol (PNP), Cr6+ and rhodamine 6G (R6G) dye were determined with the help of UV-visible spectrophotometer. Among the catalysts, the system loaded with V2O5 NP has higher kapp values. The experimental results are critically analyzed and compared with the previously available literature values. Copyright © 2020 BCREC Group. All rights reserved 

The Ultimate Biodegradation of the Starch Based Biodegradable Plastics

2012 ◽  
Vol 506 ◽  
pp. 327-330 ◽  
Author(s):  
Parichai Intaraksa ◽  
Yositar Rudeekit ◽  
Pongsaks Siriyota ◽  
P. Chaiwutthinan ◽  
M. Tajan ◽  
...  
Keyword(s):  
Aerobic Biodegradation ◽  
Poly Lactic Acid ◽  
Lag Phase ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Biodegradation Rate ◽  
Testing Period ◽  
Good Accordance ◽  
Ft Ir ◽  
Scanning Electron

The objective of this work was to investigate the ultimate aerobic biodegradation of poly (lactic acid) (PLA) and poly (butylene adipate-co-terephthalate) (PBAT), with and without the starch according to ISO14855-1: 2004. The degree of biodegradation for 120 days of PLA, PLA/starch (50:50), PBAT and PBAT/starch (50:50) were 85.75%, 93.60%, 23.71% and 73.32%, respectively. The degree of biodegradation of cellulose was 70.20% under the same conditions. For PLA, a lag phase was observed during the first twenty days of the testing. This result indicated that there was no ultimate biodegradation occurred at the beginning of testing period of PLA. However, no lag phase was observed in the biodegrability testing of the PLA/starch (50:50), PBAT and PBAT/starch (50:50). Moreover, the addition of starch into the polymers leads to higher biodegradation rate of the materials. Finally, the biodegradation results were confirmed by thermal gravimetric analysis (TGA), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM). It was found that the results of TGA, FT-IR and SEM were in good accordance with the biodegradation results.

Facile Biomimetic Fabrication of Hollow Hydroxyapatite with Hierarchically Porous Microstructure Using Hyperbranched Gemini Surfactant as Template

2014 ◽  
Vol 1015 ◽  
pp. 355-358 ◽  
Author(s):  
Shan Li ◽  
Hua Hong Wu ◽  
Guo Jie Xu ◽  
Xiu Feng Xiao
Keyword(s):  
Electron Microscopy ◽  
Mass Fraction ◽  
Surfactant Concentration ◽  
Gemini Surfactant ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
X Ray ◽  
Porous Microstructure ◽  
Ft Ir ◽  
Scanning Electron

We successfully developed a facile synthetic way to 3D hollow HAp microspheres. We used Ca (NO3)2and (NH4)3PO4as materials, hyperbranched Gemini surfactant (PCD) as template.We used some techniques to characterize the products,such as X-ray powder diffraction (XRD), Fourier transform infrared spectroscope (FT-IR), Scanning electron microscopy (SEM) and Thermal gravimetric analysis (TG).The effects of the Gemini surfactant concentration on the morphology and crystal degree of the samples were analyzed.We proposed a possible growth of mechanism.The product morphology could vary from rod to hollow sphere by adjusting the template concentration.When the template concentration was low,ball-like hydroxyapatite preliminary formed.With increasing the template concentration,the crystal degree of products declined. While the spherical cluster composed of numbers of flake or needle architectures were appeared. The results show that when the mass fraction of template is 0.01%,we can product uniform well-defined hollow spherical hydroxyapatite with semidiameter about 1.5μm.

Preparation and Characteristics of Electrospun Silver-Containing PHBV Ultrafine Fiber

2014 ◽  
Vol 548-549 ◽  
pp. 34-37 ◽  
Author(s):  
Ming Hua Min ◽  
Yu Yuan Shi ◽  
Xiao Xue Chen ◽  
Jian Gao Shi ◽  
Hai You Ma ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Average Diameter ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Ultrafine Fibers ◽  
Ultrafine Fiber ◽  
Thermal Stability Of ◽  
Scanning Electron

The effects of synthesized silver nanoparticles on electrospun PHBV ultrafine fibers were studied by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA). Addition of silver nanoparticles increased from 0.1% to 2.0%, the sooth ultrafine fiber with an average diameter of about 2 μm formed a non-woven mat was obtained. DSC showed the efficient heterogeneous nucleation by the silver nanoparticles for facilitating PHBV crystallization.The thermal stability of the PHBV/Ag ultrafine fibers improved with the increase in the content of the silver nanoparticles.

Effect of Synthesis Temperature on Particles Size and Morphology of Zirconium Oxide Nanoparticle

2017 ◽  
Vol 50 ◽  
pp. 18-31 ◽  
Author(s):  
Rudzani Sigwadi ◽  
Simon Dhlamini ◽  
Touhami Mokrani ◽  
Patrick Nonjola
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Zirconium Oxide ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Crystallite Sizes ◽  
Ft Ir

The paper presents the synthesis and investigation of zirconium oxide (ZrO2) nanoparticles that were synthesised by precipitation method with the effects of the temperatures of reaction on the particles size, morphology, crystallite sizes and stability at high temperature. The reaction temperature effect on the particle size, morphology, crystallite sizes and stabilized a higher temperature (tetragonal and cubic) phases was studied. Thermal decomposition, band structure and functional groups were analyzed by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Thermo-gravimetric analysis (TGA) and Fourier transform infrared (FT-IR). The crystal structure was determined using X-ray diffraction. The morphology and the particle size were studied using (SEM) and (TEM). The shaped particles were confirmed through the SEM analysis. The transmission electron microscopic analysis confirmed the formation of the nanoparticles with the particle size. The FT-IR spectra showed the strong presence of ZrO2 nanoparticles.

scholarly journals Single-Macromolecular Level Imaging of a Hydrogel Structure

2021 ◽  
Author(s):  
Ryuji Kiyama ◽  
Takayuki Nonoyama ◽  
Sedlacik Tomas ◽  
Hiroshi Jinnai ◽  
Jian Ping Gong
Keyword(s):  
Polymer Network ◽  
Mesh Size ◽  
Fixation Method ◽  
Gel Properties ◽  
Cell Scaffolds ◽  
Transmission Electron ◽  
Hydrogel Network ◽  
Network Observation ◽  
Surface Network ◽  
First Time

Hydrogels are promising materials for several applications, including cell scaffolds and artificial load-bearing substitutes (cartilages, ligaments, tendons, etc.). Direct observation of the nanoscale polymer network of hydrogels is essential in understanding its properties. However, imaging of individual network strands at the molecular level is not achieved yet due to the lack of suitable methods. Herein, for the first time, we developed a novel mineral-staining method and network fixation method for transmission electron microscopy observation to visualize the hydrogel network in its unperturbed conformation with nanometer resolution. Surface network observation indicates that the length of surface dangling chains, which play a major role in friction and wetting, can be estimated from the gel mesh size. Moreover, bulk observations reveals a hierarchical formation mechanism of gel heterogeneity. These observations have the great potential to advance gel science by providing comprehensive perspective that link bulk gel properties with nanoscale.

Synthesis of Uniform and High Density Silver Nanoparticles by using Peltophorum pterocarpum flower Extract

2014 ◽  
Vol 1584 ◽  
Author(s):  
Matheswaran BALAMURUGAN ◽  
Shanmugam SARAVANAN ◽  
Naoki OHTANI
Keyword(s):  
Silver Nanoparticles ◽  
Fourier Transform ◽  
Electron Microscope ◽  
Ultra Violet ◽  
Capping Agent ◽  
Nanosized Particles ◽  
Flower Extract ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Ft Ir

ABSTRACTSilver nanoparticle (AgNP) is one of the elegant material because its uses in various fields. In this study, AgNPs have been prepared by using Peltophorum pterocarpum (PP) flower extract as reducing and capping agent and aqueous silver nitrate (aq.AgNO3) as silver precursor. The synthesized nanoparticles were characterized using Ultra Violet - Visible (UV-Vis) spectroscopy, High Resolution Transmission Electron Microscope (HR-TEM) and Fourier Transform Infrared Spectroscopy (FT-IR), which reveals the formation of nanosized particles. The UV-Vis spectrum shows an absorption peak around 430nm. HR-TEM images of AgNPs with clear morphology and well dispersed prepared AgNPs.

Smart Hydrogels for Pharmaceutical Applications

2017 ◽  
pp. 1133-1164
Author(s):  
Snežana S. Ilić-Stojanović ◽  
Ljubiša B. Nikolić ◽  
Vesna D. Nikolić ◽  
Slobodan D. Petrović
Keyword(s):  
Electric Fields ◽  
Polymer Network ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Stimuli Responsive ◽  
Crosslinking Degree ◽  
Color Transparency ◽  
Hydrogel Network ◽  
Physical And Chemical ◽  
Responsive Hydrogels

The latest development in the field of smart hydrogels application as drugs carriers is shown in this chapter. Hydrogels are three-dimensional polymer network consisting of at least one hydrophilic monomer. They are insoluble in water, but in the excess presence of water or physiological fluids, swell to the equilibrium state. The amount of absorbed water depends on the chemical composition and the crosslinking degree of 3D hydrogel network and reaches over 1000% of the xerogel weight. Stimuli-responsive hydrogels exhibit significant change of their properties (swelling, color, transparency, conductivity, shape) due to small changes in the external environment conditions (pH, ionic strength, temperature, light wavelength, magnetic or electric fields, ultrasound, or a combination thereof). This smart hydrogels, with different physical and chemical properties, chemical structure and technology of obtaining, show great potential for application in the pharmaceutical industry. The application of smart hydrogels is very promising and at the beginning of the development and exploitation.

scholarly journals SILVER NANOPARTICLES FROM MEDICINALLY IMPORTANT EUPHORBIA CYATHOPHORA EXTRACT: BIOSYNTHESIS, CHARACTERIZATION, AND ANTICANCER ACTIVITY.

2018 ◽  
Vol 11 (2) ◽  
pp. 154
Author(s):  
Robert Lotha ◽  
Aravind Sivasubramanian ◽  
Meenakshi Sundaram Muthuraman
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Cell Line ◽  
Aqueous Extract ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Transmission Electron ◽  
The Stability ◽  
Ht 29 ◽  
Scanning Electron

Objective: The present study was aimed at the biosynthesis of silver nanoparticles (AgNPs) using aqueous extract of Euphorbia cyathophora leavesand testing their anticancer potential using HT-29 cell line model.Methods: Green synthesis of silver nanoparticles was obtained with the aqueous extract of E. cyathophora. The synthesized nanoparticles wereconfirmed initially by ultraviolet-visible spectroscopy. Further, scanning electron microscopy, transmission electron microscopy, and X-Ray diffractionstudies also ensured the presence of silver nanoparticles. Zeta potential studies revealed the stability of the silver nanoparticles.Results: Antioxidant and anticancer studies of the nanoparticles against HT-29 cell line exhibited remarkable results.Conclusion: This ensures that the synthesized nanoparticles play an important role in medicinal biology.

The Use of a Small, Low-Cost FT-IR Spectrometer as a Mobile Analyzer for Fluid Streams

1985 ◽  
Vol 39 (6) ◽  
pp. 909-915 ◽  
Author(s):  
D. A. C. Compton ◽  
M. Markelov ◽  
M. L. Mittleman ◽  
J. G. Grasselli
Keyword(s):  
Mobile Applications ◽  
Low Cost ◽  
Gel Permeation Chromatography ◽  
Infrared Analysis ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Evolved Gases ◽  
Gel Permeation ◽  
Ft Ir ◽  
Being Moved

Infrared analysis is well established as a prime method for identification of unknown samples. However, the instruments needed for recording a complete infrared spectrum have not lent themselves to mobile applications because of their inherent mechanical fragility. The design of a commercial low-cost FT-IR instrument described herein makes it particularly useful as a mobile analyzer since it is optically rugged and has sufficient on-board computer power to record high-quality spectra after being moved between locations. At the same time, it is physically small enough to be mounted on a standard lab cart along with the necessary accessories. We illustrate the use of this mobile, low-cost FT-IR for analyzing the evolved gases from Thermal Gravimetric Analysis, small pilot reactors, and the liquid eluant from Gel Permeation Chromatography.

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