Electrospinning and Characterization of Novel Opuntia ficus-indica Mucilage Biomembrane

2012 ◽  
Vol 1480 ◽  
Author(s):  
Sylvia W. Thomas ◽  
Norma A. Alcantar ◽  
Yanay Pais
Keyword(s):  
Acetic Acid ◽  
Acid Solution ◽  
Acetic Acid Solution ◽  
Volume Ratio ◽  
Average Diameter ◽  
Low Molecular Weight ◽  
Opuntia Ficus Indica ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTOpuntia ficus-indica (Ofi) cactus non-gelling (NE) mucilage nanofibers were electrospun with acetic acid solution and polyvinyl alcohol (PVA) as a polymer. The best fiber coverage was achieved with an aqueous 50% acetic acid solution and 9% low molecular weight PVA at a 70:30 PVA:Mucilage volume ratio. Other volume ratios (30:70 and 50:50) produced beads and other deformities. Fibers were formed with an average diameter of 180nm as measured by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Favorable electrospinning conditions were used to fabricate a 1 cm x 1 cm Ofi nanofiber biomembrane. Heat flow (W/g) versus temperature peaks ranged from 214 – 222°C, which is comparable to endothermic peak ranges observed for crystalline PVA. This could possibly further indicate some form of crystallinity within the Ofi nanofiber membrane. The electrospun process used precursors that were biodegradable, non-toxic, and sustainable to optimize the mucilage nanofiber formation, which will help enhance the potential performance of the Ofi nanofiber biomembrane in filtration and sensory systems.

scholarly journals Inkjet Printing of Controlled ZnO Nanoparticles Layering

2019 ◽  
Vol 8 (1) ◽  
pp. 34-40
Author(s):  
N. Spinella ◽  
C. Galati ◽  
L. Renna
Keyword(s):  
Zno Nanoparticles ◽  
Gas Sensing ◽  
High Surface ◽  
Volume Ratio ◽  
Specific Chemical ◽  
Force Microscopy ◽  
Electron Microscopies ◽  
Atomic Force ◽  
Preliminary Study

 Controlled layering of functional material can produced a versatile film with specific chemical and physical proprieties for desirable applications. This article presented inkjet multilayer structures of ZnO nanoparticles of specific layer morphology and thickness for the development of devices where a high surface-to-volume ratio is required (e.g. micro gas sensors). Stacked multilayers were stratified through a multi-run printing process suitable to produce large-square pattern on flat silicon support. The formation of a multilayer structure was demonstrate through an extended structural characterization of the resulting film. Printed layer morphology was investigated with optical and scanning electron microscopies; atomic force microscopy profiling characterizations were conducted over the entire printed area to evaluate the pattern reproducibility. Finally, a preliminary study as gas sensing film was performed, using the alcohol/ZnO interaction experiments.

Development and Characterization of β- Tricalcium Phosphate Cements Containing Chitosan

2006 ◽  
Vol 309-311 ◽  
pp. 845-848 ◽  
Author(s):  
Marina S. Tonoli ◽  
Claudinete V. Leal ◽  
Cecília A.C. Zavaglia ◽  
Marisa Masumi Beppu
Keyword(s):  
Acetic Acid ◽  
Calcium Phosphate ◽  
Phosphoric Acid ◽  
Acid Solution ◽  
Acetic Acid Solution ◽  
Chitosan Solution ◽  
Phosphoric Acid Solution ◽  
Mechanical Resistance ◽  
Total Acid

Cements were prepared by mixing the calcium phosphate (β-TCP) with phosphoric acid solution (2.6M) and chitosan solution (2.5% in acetic acid solution) that was added in different proportions, ranging from 1 to 50% of total acid solution amount. Observations using SEM showed that the used of chitosan increased the interconnectivity of grains in the final cement, although the mechanical resistance to compression decreased from approximately 3 to 1 MPa. Probably the chitosan macromolecule is able to form a more interconnected net.

scholarly journals Multicomponent Network Formation in Selective Layer of Composite Membrane for CO2 Separation

Membranes ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 174
Author(s):  
Jelena Lillepärg ◽  
Evgeni Sperling ◽  
Marit Blanke ◽  
Martin Held ◽  
Sergey Shishatskiy
Keyword(s):  
Network Formation ◽  
Composite Membranes ◽  
Low Molecular Weight ◽  
Scanning Calorimetry ◽  
Selective Layer ◽  
Characterization Methods ◽  
Force Microscopy ◽  
Thin Film Composite ◽  
Atomic Force

As a promising material for CO2/N2 separation, PolyActiveTM can be used as a separation layer in thin-film composite membranes (TFCM). Prior studies focused on the modification of PolyActiveTM using low-molecular-weight additives. In this study, the effect of chemical crosslinking of reactive end-groups containing additives, forming networks within selective layers of the TFCM, has been studied. In order to understand the influence of a network embedded into a polymer matrix on the properties of the resulting materials, various characterization methods, including Fourier transform infrared spectroscopy (FTIR), gas transport measurements, differential scanning calorimetry (DSC) and atomic force microscopy (AFM), were used. The characterization of the resulting membrane regarding individual gas permeances by an in-house built “pressure increase” facility revealed a twofold increase in CO2 permeance, with insignificant losses in CO2/N2 selectivity.

Characterization of InP/GaInAs Nanometer Sized Columns Produced by Aerosol Deposition and Plasma Etching

1994 ◽  
Vol 332 ◽  
Author(s):  
I. Maximov ◽  
K. Deppert ◽  
L. Montelius ◽  
L. Samuelson ◽  
S. Gray ◽  
...  
Keyword(s):  
Plasma Etching ◽  
Electron Cyclotron Resonance ◽  
Average Diameter ◽  
Aerosol Deposition ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Ag Particles

ABSTRACTWe present a technique for the fabrication of InP nano-columns and GaInAs/InP quantum-dots based on the use of sintered aerosol Ag particles as a mask in an electron cyclotron resonance etching process. The sintered particles have much more regular shapes than the unsintered ones used in previous studies and are more resistant to the etching environment, which results in the formation of more regular and reproducible structures. For example, we have been able to produce columns 100 nm in height which have an average diameter of 24 nm and a density of 109 cm−2.We have investigated the shape of the etched columns as a function of the Ag particles’ size, and characterized their electrical and optical properties using a combination of scanning electron microscopy, scanning tunneling microscopy, atomic force microscopy, and photoluminescence.

Preparation of Chitosan Nanospheres by Miniemulsion Crosslinking Method

2015 ◽  
Vol 1094 ◽  
pp. 68-71
Author(s):  
Qing Shan Liu ◽  
Qing Fang Yan ◽  
Xiao Ying Yin
Keyword(s):  
Particle Size ◽  
Acetic Acid ◽  
Acid Solution ◽  
Size Distribution ◽  
Aqueous Phase ◽  
Acetic Acid Solution ◽  
Volume Ratio ◽  
Preparation Condition ◽  
Paraffin Liquid

Objective To obtain immobilized nanomaterials with good performance, the preparation condition of chitosan nanospheres by miniemulsion crosslinking method was optimized. Methods The chitosan nanospheres were synthesized by miniemulsion crosslinking method with Span80 and Tween80 as the emulsifier, glutaraldehyde as the crosslinker, n-hexane and paraffin liquid as oil phase,chitosan acetic acid solution as aqueous phase. The particle size was measured by Zetasizer nanoanalyzer. Results The results of the univariate tests show that the optimal preparation condition of chitosan nanospheres can be obtained when water/oil volume ratio is 3:2. The size distribution of chitosan nanospheres is 18.17nm to 190.1nm. Conclusion The chitosan nanospheres by miniemulsion crosslinking method are suitable materials as enzymes and proteins immobilized carrier.

Some Approaches to Viscometric Study of Chitosan in Acetic Acid Solution

2016 ◽  
Vol 10 (2) ◽  
pp. 135-139 ◽  
Author(s):  
Valentina Chernova ◽  
◽  
Angela Shurshina ◽  
Elena Kulish ◽  
Gennady Zaikov ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Acid Solution ◽  
Intrinsic Viscosity ◽  
Acetic Acid Solution ◽  
Conformational State ◽  
Macromolecular Coil ◽  
Degree Of Swelling ◽  
Current Value ◽  
Viscometric Study

Some ways of estimating the values of the intrinsic viscosity of chitosan were analyzed. It was shown that the method of Irzhak and Baranov for estimating the current value of the intrinsic viscosity allows to adequately estimates the conformational state of the macromolecular coil and its degree of swelling.

Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid-beta M1-42

2019 ◽  
Author(s):  
Priya Prakash ◽  
Travis Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra
Keyword(s):  
Amyloid Beta ◽  
Western Blots ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
Set Up ◽  
Short Time

Amyloid plaques found in the brains of Alzheimer’s disease (AD) patients primarily consists of amyloid beta 1-42 (Ab42). Commercially, Ab42 is synthetized using peptide synthesizers. We describe a robust methodology for expression of recombinant human Ab(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli with refined and rapid analytical purification techniques. The peptide is isolated and purified from the transformed cells using an optimized set-up for reverse-phase HPLC protocol, using commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) in a short time. The recombinant Ab(M1-42) forms characteristic aggregates similar to synthetic Ab42 aggregates as verified by western blots and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique to purify human Ab(M1-42) can be used to synthesize chemical probes for several downstream in vitro and in vivo assays to facilitate AD research.

Low Molecular Weight Microfibers with Light Sensing Properties

2017 ◽  
Vol 54 (4) ◽  
pp. 655-658
Author(s):  
Andrei Bejan ◽  
Dragos Peptanariu ◽  
Bogdan Chiricuta ◽  
Elena Bicu ◽  
Dalila Belei
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight ◽  
X Ray Diffraction ◽  
Aromatic Rings ◽  
X Ray ◽  
Force Microscopy ◽  
Light Sensing ◽  
Sensing Applications ◽  
Atomic Force ◽  
Low Molecular Weight Compounds

Microfibers were obtained from organic low molecular weight compounds based on heteroaromatic and aromatic rings connected by aliphatic spacers. The obtaining of microfibers was proved by scanning electron microscopy. The deciphering of the mechanism of microfiber formation has been elucidated by X-ray diffraction, infrared spectroscopy, and atomic force microscopy measurements. By exciting with light of different wavelength, florescence microscopy revealed a specific optical response, recommending these materials for light sensing applications.

Biopolymers with Medical Applications Optimized method for obtaining chitosan-based delivery systems

2018 ◽  
Vol 69 (7) ◽  
pp. 1756-1759 ◽  
Author(s):  
Luminita Confederat ◽  
Iuliana Motrescu ◽  
Sandra Constantin ◽  
Florentina Lupascu ◽  
Lenuta Profire
Keyword(s):  
Drug Delivery ◽  
Drug Delivery Systems ◽  
Average Diameter ◽  
Delivery Systems ◽  
Cross Linking ◽  
Low Molecular Weight ◽  
Polymeric Systems ◽  
Chitosan Microparticles ◽  
Degree Of Swelling

The aim of this study was to optimize the method used for obtaining microparticles based on chitosan � a biocompatible, biodegradable, and nontoxic polymer, and to characterize the developed systems. Chitosan microparticles, as drug delivery systems were obtained by inotropic gelation method using pentasodiumtripolyphosphate (TPP) as cross-linking agent. Chitosan with low molecular weight (CSLMW) in concentration which ranged between 0.5 and 5 %, was used while the concentration of cross-linking agent ranged between 1 and 5%. The characterization of the microparticles in terms of shape, uniformity and adhesion was performed in solution and dried state. The size of the microparticles and the degree of swelling were also determined. The structure and the morphology of the developed polymeric systems were analyzed by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM).The average diameter of the chitosan microparticles was around 522 �m. The most stable microparticles were obtained using CSLMW 1% and TPP 2% or CSLMW 0.75%and TPP 1%. The micropaticles were spherical, uniform and without flattening. Using CSLMW in concentration of 0.5 % poorly cross-linked and crushed microparticles have been obtained at all TPP concentrations. By optimization of the method, stable chitosan-based micropaticles were obtained which will be used to develop controlled release systems for drug delivery.

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