scholarly journals Tb3+/Eu3+ Complex-Doped Rigid Nanoparticles in Transparent Nanofibrous Membranes Exhibit High Quantum Yield Fluorescence

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 694 ◽  
Author(s):  
Peng Lu ◽  
Yanxin Wang ◽  
Linjun Huang ◽  
Sixian Lian ◽  
Yao Wang ◽  
...  
Keyword(s):  
Emission Spectra ◽  
Electrospinning Process ◽  
Fluorescence Properties ◽  
Quantum Yields ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Β Phase ◽  
Atomic Force ◽  
Potential Applications ◽  
Fibrous Membranes

In this study, transparent membranes containing luminescent Tb3+ and Eu3+ complex-doped silica nanoparticles were prepared via electrospinning. We prepared the electrospun fibrous membranes containing Tb(acac)3phen- (acac = acetylacetone, phen = 1,10-phenanthroline) and/or Eu(tta)3phen- (tta = 2-thenoyltrifluoroacetone) doped silica (M-Si-Tb3+ and M-Si-Eu3+) and studied their photoluminescence properties. The fibrous membranes containing the rare earth complexes were prepared by electrospinning. The surface morphology and thermal properties of the fibrous membrane were studied by atomic force microscopy (AFM), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), respectively. Fluorescence spectroscopy was used to characterize the fluorescence properties of the membranes. During the electrospinning process, the PVDF transitions from the α phase to the β phase, which exhibits a more rigid structure. The introduction of rigid materials, like PVDF and silica, can improve the fluorescence properties of the hybrid materials by reducing the rate of nonradiative decay. So the emission spectra at 548 nm (Tb) and 612 nm (Eu) were enhanced, as compared to the emission from the pure complex. Furthermore, the fluorescence lifetimes ranged from 0.6 to 1.5 ms and the quantum yields ranged from 32% to 61%. The luminescent fibrous membranes have potential applications in the fields of display panels, innovative electronic and optoelectronic devices.

scholarly journals Preparation and Evaluation of Nanofibrous Hydroxypropyl Cellulose and β-Cyclodextrin Polyurethane Composite Mats

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 754
Author(s):  
Luiza Madalina Gradinaru ◽  
Mihaela Barbalata-Mandru ◽  
Mioara Drobota ◽  
Magdalena Aflori ◽  
Maria Spiridon ◽  
...  
Keyword(s):  
Morphological Structure ◽  
Tensile Tests ◽  
Hydroxypropyl Cellulose ◽  
Scanning Calorimetry ◽  
Electrospinning Technique ◽  
Force Microscopy ◽  
Polyurethane Composite ◽  
Atomic Force ◽  
Potential Applications ◽  
Preparation And Evaluation

A series of nanofibrous composite mats based on polyurethane urea siloxane (PUUS), hydroxypropyl cellulose (HPC) and β-cyclodextrin (β-CD) was prepared using electrospinning technique. PUUS was synthesized by two steps solution polymerization procedure from polytetramethylene ether glycol (PTMEG), dimethylol propionic acid (DMPA), 4,4′-diphenylmethane diisocyanate (MDI) and 1,3-bis-(3-aminopropyl) tetramethyldisiloxane (BATD) as chain extender. Then, the composites were prepared by blending PUUS with HPC or βCD in a ratio of 9:1 (w/w), in 15% dimethylformamide (DMF). The PUUS and PUUS based composite solutions were used for preparation of nanofibrous mats. In order to identify the potential applications, different techniques were used to evaluate the chemical structure (Fourier transform infrared-attenuated total reflectance spectroscopy—FTIR-ATR), morphological structure (Scanning electron microscopy—SEM and Atomic force microscopy—AFM), surface properties (contact angle, dynamic vapors sorption—DVS), mechanical characteristics (tensile tests), thermal (differential scanning calorimetry—DSC) and some preliminary tests for biocompatibility and microbial adhesion.

scholarly journals The Infuence of Salicin on Rheological and Film-Forming Properties of Collagen

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1661
Author(s):  
Katarzyna Adamiak ◽  
Katarzyna Lewandowska ◽  
Alina Sionkowska
Keyword(s):  
Mechanical Properties ◽  
Atomic Force Microscopy ◽  
Infrared Spectroscopy ◽  
Rheological Properties ◽  
Silver Carp ◽  
Shear Tests ◽  
Force Microscopy ◽  
Atomic Force ◽  
Film Forming ◽  
Potential Applications

Collagen films are widely used as adhesives in medicine and cosmetology. However, its properties require modification. In this work, the influence of salicin on the properties of collagen solution and films was studied. Collagen was extracted from silver carp skin. The rheological properties of collagen solutions with and without salicin were characterized by steady shear tests. Thin collagen films were prepared by solvent evaporation. The structure of films was researched using infrared spectroscopy. The surface properties of films were investigated using Atomic Force Microscopy (AFM). Mechanical properties were measured as well. It was found that the addition of salicin modified the roughness of collagen films and their mechanical and rheological properties. The above-mentioned parameters are very important in potential applications of collagen films containing salicin.

scholarly journals Preparation, Thermal, and Thermo-Mechanical Characterization of Polymeric Blends Based on Di(meth)acrylate Monomers

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 878
Author(s):  
Krystyna Wnuczek ◽  
Andrzej Puszka ◽  
Łukasz Klapiszewski ◽  
Beata Podkościelna
Keyword(s):  
Mechanical Analysis ◽  
Attenuated Total Reflection ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Chemical Structures ◽  
Atomic Force ◽  
Polymeric Blends ◽  
Ft Ir ◽  
Acrylate Monomers ◽  
Synthesized Materials

This study presents the preparation and the thermo-mechanical characteristics of polymeric blends based on di(meth)acrylates monomers. Bisphenol A glycerolate diacrylate (BPA.GDA) or ethylene glycol dimethacrylate (EGDMA) were used as crosslinking monomers. Methyl methacrylate (MMA) was used as an active solvent in both copolymerization approaches. Commercial polycarbonate (PC) was used as a modifying soluble additive. The preparation of blends and method of polymerization by using UV initiator (Irqacure® 651) was proposed. Two parallel sets of MMA-based materials were obtained. The first included more harmless linear hydrocarbons (EGDMA + MMA), whereas the second included the usually used aromatic copolymers (BPA.GDA + MMA). The influence of different amounts of PC on the physicochemical properties was discussed in detail. Chemical structures of the copolymers were confirmed by attenuated total reflection–Fourier transform infrared (ATR/FT-IR) spectroscopy. Thermo-mechanical properties of the synthesized materials were investigated by means of differential scanning calorimetry (DSC), thermogravimetric (TG/DTG) analyses, and dynamic mechanical analysis (DMA). The hardness of the obtained materials was also tested. In order to evaluate the surface of the materials, their images were obtained with the use of atomic force microscopy (AFM).

Preparation and Characterization of Chitosan-Casein Phosphopeptides Biocomposite Coatings on the Medical Titanium Alloy

2011 ◽  
Vol 480-481 ◽  
pp. 1065-1069
Author(s):  
Bin Liu ◽  
Lin Wang ◽  
Yin Zhong Bu ◽  
Sheng Rong Yang ◽  
Jin Qing Wang
Keyword(s):  
Photoelectron Spectroscopy ◽  
Attenuated Total Reflectance ◽  
Ti Alloy ◽  
Force Microscopy ◽  
Implant Materials ◽  
Atomic Force ◽  
Casein Phosphopeptides ◽  
Potential Applications ◽  
First Time

Titanium (Ti) and its alloys have been applied in orthopedics as one of the most popular biomedical metallic implant materials. In this work, to enhance the bioactivity, the surface of Ti alloy pre-modified by silane coupling agent and glutaraldehyde was covalently grafted with chitosan (CS) via biochemical multistep self-assembled method. Then, for the first time, the achieved surface was further immobilized with casein phosphopeptides (CPP), which are one group of bioactive peptides released from caseins in the digestive tract and can facilitate the calcium adsorption and usage, to form CS-CPP biocomposite coatings. The structure and composition of the fabricated coatings were characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and atomic force microscopy (AFM). As the experimental results indicated, multi-step assembly was successfully performed, and the CS and CPP were assembled onto the Ti alloy surface orderly. It is anticipated that the Ti alloys modified by CS-CPP biocomposite coatings will find potential applications as implant materials in biomedical fields.

Determination of the Physical Properties of Oil Sands Components using Scanning Probe Microscopy

2015 ◽  
Vol 1754 ◽  
pp. 69-74
Author(s):  
Ravi Gaikwad ◽  
Tinu Abraham ◽  
Aharnish Hande ◽  
Fatemeh Bakhtiari ◽  
Siddhartha Das ◽  
...  
Keyword(s):  
Oil Sands ◽  
Structural Changes ◽  
Rational Approach ◽  
Kelvin Probe ◽  
Scanning Calorimetry ◽  
Probe Microscopy ◽  
Kelvin Probe Microscopy ◽  
Force Microscopy ◽  
Atomic Force

ABSTRACTAtomic force microscopy is employed to study the structural changes in the morphology and physical characteristics of asphaltene aggregates as a function of temperature. The exotic fractal structure obtained by evaporation-driven asphaltene aggregates shows an interesting dynamics for a large range of temperatures from 25°C to 80°C. The changes in the topography, surface potential and adhesion are unnoticeable until 70°C. However, a significant change in the dynamics and material properties is displayed in the range of 70°C - 80°C, during which the aspahltene aggregates acquire ‘liquid-like’ mobility and fuse together. This behaviour is attributed to the transition from the pure amorphous phase to a crystalline liquid phase which occurs at approximately 70°C as shown by using Differential Scanning Calorimetry (DSC). Additionally, the charged nature of asphaltenes and bitumen is also explored using kelvin probe microscopy. Such observations can lead to the development of a rational approach to the fundamental understanding of asphaltene aggregation dynamics and may help in devising novel techniques for the handling and separation of asphaltene aggregates using dielectrophoretic methods.

Microstructural Study of a Passivation Layer on GaAs: An Application of X-Ray Reflectivity Under Grazing Angles Using a Synchrotron Source

2003 ◽  
Vol 10 (02n03) ◽  
pp. 373-379 ◽  
Author(s):  
K. E. Crompton ◽  
T. R. Finlayson ◽  
C. Kirchner ◽  
M. Seitz ◽  
U. Klemradt
Keyword(s):  
External Surface ◽  
Synchrotron Source ◽  
Microstructural Study ◽  
X Ray ◽  
Force Microscopy ◽  
Microstructural Parameters ◽  
Atomic Force ◽  
Potential Applications ◽  
Grazing Angles ◽  
Mode Atomic Force Microscopy

X-ray specular reflectivities of GaAs samples passivated with a thin film of (3-mercaptopropyl)-trimethoxysilane (MPT) have been studied using bending-magnet synchrotron radiation. Various preparation procedures covering etching the GaAs, MPT deposition and its baking have been investigated. An oxide film is always observed between the GaAs and MPT films. The microstructural parameters, such as film thickness, density and interfacial roughness (including the external surface), have been determined from appropriate modeling of the reflectivity. The surface roughness has been compared with a direct measurement using tapping-mode atomic force microscopy. The results are discussed with reference to the potential applications of GaAs as a biosensor.

scholarly journals Applications of Atomic Force Microscopy in Textiles

2015 ◽  
Vol 10 (1) ◽  
pp. 155892501501000
Author(s):  
Serpil Koral Koc
Keyword(s):  
Atomic Force Microscopy ◽  
Cross Section ◽  
Cross Sections ◽  
Phase Imaging ◽  
Cotton Wool ◽  
Synthetic Fibers ◽  
Force Microscopy ◽  
Fiber Properties ◽  
Atomic Force ◽  
Potential Applications

Potential applications of atomic force microscopy (AFM) in textiles are explained. For this purpose samples were carefully selected from both natural and synthetic fibers. Cotton, wool, conventional polyethylene terepthalate (PET), antibacterial PET, and antistatic PET were investigated by means of 3D topography imaging, phase imaging, and calculation of their Rq values. The distribution of the additives in the cross sections of antibacterial PET and antistatic PET were analyzed. Moreover, differences between inner and outer cross section of trilobal PET was observed by force spectroscopy. The results are discussed considering the fiber properties. It is concluded that AFM is a powerful tool to investigate different properties of textile fibers, and it gives valuable information.

Stereocomplex electrospun fibers from high molecular weight of poly(L-lactic acid) and poly(D-lactic acid)

2020 ◽  
Vol 40 (2) ◽  
pp. 136-142 ◽  
Author(s):  
Homa Maleki ◽  
Hossein Barani
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Thermal Properties ◽  
High Molecular Weight ◽  
Chemical Properties ◽  
Electrospun Fibers ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Atomic Force ◽  
Electrospinning Method

AbstractThe stereocomplex formation is a promising method to improve the properties of poly(lactide) (PLA)-based products due to the strong interaction of the side-by-side arrangement of the molecular chains. Recently, electrospinning method has been applied to prepare PLA stereocomplex, which is more convenient. The objective of the current study is to make stereocomplexed PLA nanofibers using electrospinning method and compare their properties and structures with pure poly(l-lactide) (PLLA) fibers. The stereocomplexed fibers were electrospun from a blend solution of high molecular weight PLLA and poly(d-lactide) (1:1 ratio). The morphology of the obtained electrospun fibers was examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). Differential scanning calorimetry was applied to study their thermal properties and crystallinity. Fourier transform infrared spectroscopy (FTIR) test was conducted on the samples to characterize their chemical properties. The SEM and AFM images indicated that smooth uniform fibers with a cylindrical structure were produced. Besides, the FTIR results and thermal properties confirmed that only stereocomplex crystallites formed in the resulting fibers via the electrospinning method.

GROWTH AND STUDIES OF PROPERTIES OF COPPER SUCCINATE DIHYDRATE SINGLE CRYSTALS

2013 ◽  
Vol 27 (11) ◽  
pp. 1350073
Author(s):  
M. P. BINITHA ◽  
P. P. PRADYUMNAN
Keyword(s):  
Differential Scanning Calorimetry ◽  
Dielectric Constant ◽  
Single Crystals ◽  
Scanning Calorimetry ◽  
Force Microscopy ◽  
Atomic Force ◽  
Different Temperatures ◽  
Triclinic Structure ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Single crystals of copper succinate dihydrate (CSD) with triclinic structure were grown in silica gel medium. The functional groups in the crystal were analyzed by FT-IR Spectroscopy. Atomic Force Microscopy (AFM) revealed the striations on the surface of grown crystals, which were incorporated during its time of growth. Thermal degradation studies have been carried out by Differential Scanning Calorimetry (DSC). Dielectric constant and AC conductivity have been estimated as a function of frequency at different temperatures.

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