Development of new ceramic doped ionoconducting membranes for biomedical applications.

2002 ◽  
Vol 756 ◽  
Author(s):  
Paola Romagnoli ◽  
Maria Luisa Di Vona ◽  
Enrico Traversa ◽  
Livio Narici ◽  
Walter G. Sannita ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Titanium Oxide ◽  
Polymethyl Methacrylate ◽  
Biomedical Applications ◽  
Composite Membranes ◽  
Spectroscopic Studies ◽  
Mas Nmr ◽  
Lithium Salts ◽  
Polymeric Electrolytes ◽  
Electroencephalogram Eeg

ABSTRACTNew ionoconducting composite membranes to be used as an interface between the skin and the actual electrical instrumentation used to produce an electroencephalogram (EEG) have been developed. The gels are based on lithium salts and PMMA (polymethyl methacrylate) and have been doped with nanometric titanium oxide. The samples have been electrochemically characterized by means of impedance spectroscopy and their structure studied by ATR-FTIR and MAS NMR. Spectroscopic studies indicate interactions between the polymer and oxide dopant. The polymeric electrolytes allowed the registration of good electrophysiological cortical signals either spontaneous or stimulus-related.

Characterization of novel activated composite membranes by impedance spectroscopy

1998 ◽  
Vol 451 (1-2) ◽  
pp. 173-180 ◽  
Author(s):  
Juana Benavente ◽  
Maria Oleinikova ◽  
Maria Muñoz ◽  
Manuel Valiente
Keyword(s):  
Impedance Spectroscopy ◽  
Composite Membranes

scholarly journals Alumina-Hydroxyapatite-Silver Spheres With Antibacterial Activity

Dose-Response ◽  
2021 ◽  
Vol 19 (2) ◽  
pp. 155932582110113
Author(s):  
Pamela Nair Silva-Holguín ◽  
Simón Yobanny Reyes-López
Keyword(s):  
Drug Resistance ◽  
Silver Nanoparticles ◽  
Biomedical Applications ◽  
Antibacterial Properties ◽  
Spectroscopic Studies ◽  
Gram Positive ◽  
Bioactive Scaffolds ◽  
Functional Factors ◽  
Synthetic Routes ◽  
Silver Spheres

Researchers are currently looking for materials that are stable, functional, aesthetic, and biocompatible without infections. Therefore, there is a great interest in obtaining a material that has a balance between aesthetic, biological, mechanical, and functional factors, which can be used as an infection control material. The addition of hydroxyapatite to alumina make highly bioactive scaffolds with mechanical strength. Biomedical applications require antibacterial properties; therefore, this idea leads to great interest in the development of new synthetic routes of ceramic biomaterials that allow the release of nanoparticles or metal ions. This investigation presents the obtention of alumina-hydroxyapatite spheres doped with silver nanoparticles with antibacterial effect against various Gram-positive and negative bacteria related to drug-resistance infections. The microstructural and spectroscopic studies demonstrate that the spheres exhibit a homogeneous structure and crystal hydroxyapatite and silver nanoparticles are observed on the surface. The antimicrobial susceptibility was verified with the agar diffusion and turbidimetry methods in Gram-negative ( Escherichia coli and Pseudomonas aeruginosa) and Gram-positive ( Staphylococcus aureus and Bacillus subtilis) bacteria. All bacteria used were susceptible to the alumina-hydroxyapatite-silver spheres even at lower silver concentration. The composites have a higher possibility for medical applications focused on the control of drug-resistance microorganisms.

Mechanical Characterization of UV Photopolymerized PMMA with Different Photo-Initiator Concentration

2021 ◽  
Vol 903 ◽  
pp. 11-16
Author(s):  
M.A. Manjunath ◽  
K. Naveen ◽  
Prakash Vinod ◽  
N. Balashanmugam ◽  
M.R. Shankar
Keyword(s):  
Mechanical Properties ◽  
Light Source ◽  
Polymethyl Methacrylate ◽  
Biomedical Applications ◽  
Mechanical Characterization ◽  
Uv Light ◽  
Curing Time ◽  
Uv Led ◽  
Pmma Resin

Polymethyl methacrylate (PMMA) is one among few known photo-polymeric resin useful in lithography for fabricating structures having better mechanical properties to meet the requirement in electronics and biomedical applications. This study explores the effect of Photo Initiator (PI) concentration and also curing time on strength and hardness of Polymethyl methacrylate (PMMA) obtained by UV photopolymerization of Methyl methacrylate (MMA) monomer. The UV LED light source operating at the wavelength of 364 nm is used with Benzoin Ethyl Ether (BEE) as photo initiator. The curing of PMMA resin is supported with peltier cooling device placed at the bottom of the UV light source. The characterisation study of UV photo cured PMMA is analysed through nano indenter (Agilent Technologies-G200). The current work investigates the influence of PI concentration and curing time in achieving maximum mechanical properties for UV photopolymerized PMMA.

Study on lignin-free lignocellulosic biomass and PSF-PEG membrane compatibility

BioResources ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 1063-1075
Author(s):  
Abiodun A. Amusa ◽  
Abdul L. Ahmad ◽  
Jimoh K. Adewole
Keyword(s):  
Contact Angle ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Lignocellulosic Biomass ◽  
Biomedical Applications ◽  
Composite Membranes ◽  
Hydroxyl Groups ◽  
Chemical Pretreatment ◽  
Physical And Chemical ◽  
Porosity Measurements

Lignocellulosic biomass was delignified by combining physical and chemical pretreatment techniques. Then, a polysulfone-polyethylene glycol blend, which was compatible with the lignin-free biomass (0 wt% to 3.0 wt%), was used to fabricate composite membranes. The presence of hydroxyl groups after the pretreatment was evaluated via Fourier transform infrared spectroscopy. The rheology of the polymer solutions was assessed via the viscometric method. Also, the hydrophobicity of the fabricated membranes was determined using contact angle and porosity measurements. The fabricated membranes with near superhydrophobic properties (a contact angle of approximately 140°) based on this study revealed that contactor systems and biomedical applications would benefit from this modification.

H3PO4 / oxide nanoparticles / polymer composites as proton conducting membranes

2001 ◽  
Vol 703 ◽  
Author(s):  
D. Carrière ◽  
P. Barboux ◽  
M. Moreau ◽  
J.-P. Boilot
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Infrared Spectroscopy ◽  
Light Scattering ◽  
Magnetic Resonance ◽  
Impedance Spectroscopy ◽  
Composite Membranes ◽  
Oxide Nanoparticles ◽  
Zirconium Acetate ◽  
Conductive Particles ◽  
Conducting Membranes

ABSTRACTStable sols of 60 nm colloidal zirconia have been prepared by thermolysis of zirconium acetate. The surface complexing acetate groups have been replaced by phosphoric acid groups. Phosphate grafting has been characterized by dynamic light scattering, infrared spectroscopy, 31P nuclear magnetic resonance and impedance spectroscopy measurements. These systems give acid and proton conductive particles (4.10-5 S.cm-1 at 70 % relative humidity).H3PO4/ZrO2/PVDF-co-HFP composite membranes have been synthesized. Impedance spectroscopy measurements allow discrimination between proton conduction at the surface of the phosphated particles and within free H3PO4 in the polymer. For the highest H3PO4/ZrO2 ratios, the latter phenomenon prevails, giving a proton conductivity of 6.10-4 S.cm-1 at 70 % R.H.

scholarly journals Surface properties and bioactivity of TiO 2 nanotube array prepared by two-step anodic oxidation for biomedical applications

2019 ◽  
Vol 6 (4) ◽  
pp. 181948 ◽  
Author(s):  
Zhaoxiang Peng ◽  
Jiahua Ni
Keyword(s):  
Cell Adhesion ◽  
Electron Microscope ◽  
Impedance Spectroscopy ◽  
Surface Energy ◽  
Anodic Oxidation ◽  
Biomedical Applications ◽  
Nanotube Array ◽  
Measuring Device ◽  
X Ray ◽  
Cell Adhesion And Proliferation

A highly ordered TiO 2 nanotube array has been prepared on a commercial pure titanium substrate in a hydrofluoric (HF) electrolyte using a DC power source through two-step anodic oxidation. The morphology, composition, wettability and surface energy of the nanotube array have been characterized by using a field-emission scanning electron microscope (FE-SEM), a transmission electron microscope (JEM-2010) with energy-dispersive X-ray spectrometer EDX (INCA OXFORD), X-ray diffraction method, an atomic force microscope (AFM), an optical contact angle measuring device and the Owens method with two liquids. The electrochemical behaviours of anodic oxidation films with different structures have been investigated in Sodium Lactate Ringer's Injection at 37±1°C by potentiodynamic polarization curve and electrochemical impedance spectroscopy. The formation mechanism of the nanotube array and the advantages of two-step oxidation have been discussed according to the experimental observation and the characterized results. Meanwhile, the structural changes of nanotubes are analysed according to the results of impedance spectroscopy. Cytotoxicity testing and cell adhesion and proliferation have been studied in order to evaluate the bioactivity of the nanotube array film. The diameters of nanotubes are in the range of 120–140 nm. The nanotube surface shows better wettability and higher surface energy compared to the bare substrate. The nanotube surface exhibits a wide passivation range and good corrosion resistance. The growth of the nanotube array is the result of the combined action of the anodization and field-assisted dissolution. The nanotube array by two-step oxidation becomes more regular and orderly. Moreover, the nanotube array surface is non-toxic and favourable to cell adhesion and proliferation. Such nanotube array films are expected to have significant biomedical applications.

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