The Independence of Depth and Diameter in Equilibrated Free Films

1966 ◽  
pp. 144-148 ◽  
Author(s):  
D. Ekserova ◽  
Iv. Ivanov ◽  
A. Sheludko
Keyword(s):  
Free Films

scholarly journals Optical, Structural, and Dielectric Properties of Composites Based on Thermoplastic Polymers of the Polyolefin and Polyurethane Type and BaTiO3 Nanoparticles

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 753
Author(s):  
M. Baibarac ◽  
A. Nila ◽  
I. Smaranda ◽  
M. Stroe ◽  
L. Stingescu ◽  
...  
Keyword(s):  
Crystallization Process ◽  
Weight Ratio ◽  
Thermoplastic Elastomers ◽  
Visible Spectral Range ◽  
X Ray Diffraction ◽  
Thermoplastic Polymers ◽  
The Matrix ◽  
Free Films ◽  
Batio3 Nanoparticles ◽  
Properties Of Composites

In this work, new films containing composite materials based on blends of thermoplastic polymers of the polyurethane (TPU) and polyolefin (TPO) type, in the absence and presence of BaTiO3 nanoparticles (NPs) with the size smaller 100 nm, were prepared. The vibrational properties of the free films depending on the weight ratio of the two thermoplastic polymers were studied. Our results demonstrate that these films are optically active, with strong, broad, and adjustable photoluminescence by varying the amount of TPU. The crystalline structure of BaTiO3 and the influence of thermoplastic polymers on the crystallization process of these inorganic NPs were determined by X-ray diffraction (XRD) studies. The vibrational changes induced in the thermoplastic polymer’s matrix of the BaTiO3 NPs were showcased by Raman scattering and FTIR spectroscopy. The incorporation of BaTiO3 NPs in the matrix of thermoplastic elastomers revealed the shift dependence of the photoluminescence (PL) band depending on the BaTiO3 NP concentration, which was capable of covering a wide visible spectral range. The dependencies of the dielectric relaxation phenomena with the weight of BaTiO3 NPs in thermoplastic polymers blends were also demonstrated.

scholarly journals UV-A Treatment of ZrO2 Thin Films Fabricated by Environmental Friendlier Water-Based Solution Processing: Structural and Optical Studies

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 821
Author(s):  
Aneeqa Bashir ◽  
Mehwish Farooq ◽  
Abdul Malik ◽  
Shahzad Naseem ◽  
Arshad Saleem Bhatti
Keyword(s):  
Optical Properties ◽  
Low Cost ◽  
Annealed Film ◽  
Optical Transmittance ◽  
Amorphous Structure ◽  
Solution Processing ◽  
Vis Spectroscopy ◽  
Water Based ◽  
Free Films ◽  
Quartz Substrates

An environmentally friendlier solution processing has been introduced to fabricate zirconium oxide (ZrO2) films on quartz substrates, using spin coating of simple water-based solution. The films cured with UV-A = 330 nm for different times (40, 80, 120 min) were investigated for structural and optical properties and compared with thermally annealed film (at 350 °C). XRD and Raman spectroscopy showed amorphous structure in all the samples with no significant phase transformation with UV-A exposure. AFM microscopy showed smooth and crack free films with surface roughness ≤2 nm that reduced with UV-A exposure. Ultraviolet-visible (UV–Vis) spectroscopy demonstrated optical transmittance ≥88% and energy band gap variations as 4.52–4.70 eV. Optical constants were found from spectroscopic ellipsometry (SE). The refractive index (n) values, measured at 470 nm increased from 1.73 to 2.74 as the UV-A exposure prolonged indicating densification and decreasing porosity of the films. The extinction coefficient k decreased from 0.32 to 0.19 indicating reduced optical losses in the films under the UV-A exposure. The photoluminescence (PL) spectra exhibited more pronounced UV emissions which grew intense with UV-A exposure thereby improving the film quality. It is concluded that UV-A irradiation can significantly enhance the optical properties of ZrO2 films with minimal changes induced in the structure as compared to thermally treated film. Moreover, the present work indicates that water-based solution processing has the potential to produce high-quality ZrO2 films for low cost and environmental friendlier technologies. The work also highlights the use of UV-A radiations as an alternate to high temperature thermal annealing for improved quality.

Characterization of ethylcellulose free films by positron annihilation spectroscopy and mechanical testing

2014 ◽  
Vol 115 ◽  
pp. 47-50 ◽  
Author(s):  
Diána Hegyesi ◽  
Károly Süvegh ◽  
András Kelemen ◽  
Klára Pintye-Hódi ◽  
Géza Regdon
Keyword(s):  
Positron Annihilation ◽  
Mechanical Testing ◽  
Positron Annihilation Spectroscopy ◽  
Free Films

Preparation and characterization of free films of high amylose/pectin mixtures cross-linked with sodium trimetaphosphate

2012 ◽  
Vol 38 (11) ◽  
pp. 1354-1359 ◽  
Author(s):  
Fabíola Garavello Prezotti ◽  
Andréia Bagliotti Meneguin ◽  
Raul Cesar Evangelista ◽  
Beatriz Stringhetti Ferreira Cury
Keyword(s):  
Sodium Trimetaphosphate ◽  
Free Films ◽  
High Amylose

Preparation and characterization of acrylic polymer titania hybrid. A study of organicinorganic interactions in hybrid materials by micro-hardness Vickers

2002 ◽  
Vol 726 ◽  
Author(s):  
Van Nhan Nguyen ◽  
François Xavier Perrin ◽  
Jean-Louis Vernet
Keyword(s):  
Mechanical Properties ◽  
Large Scale ◽  
Sol Gel ◽  
Mechanical Analysis ◽  
Polymer Chains ◽  
Segmental Motion ◽  
Acrylic Polymer ◽  
Titania Content ◽  
Mineral Constituent ◽  
Free Films

AbstractMetal-oxide ceramer films have been developed using an acrylic polymer bearing a low amount of methacrylic acid units (ca. 4%mol) as the organic phase with titanium tetrabutoxide as the inorganic sol-gel precursor. The characterisation of free films was realized by various experimental methods. The formation of COOTi bonds prevents large scale phase separation between the organic component and the mineral network. Mechanical properties of the hybrid films have been investigated through dynamic mechanical analysis. The influence of the titania content on the damping peak amplitude suggests that titania is molecularly dispersed in the polymer matrix and that it significantly hinders the segmental motion of the polymer chains. However, the low content in potential carboxylic crosslinking sites explains why the glass transition temperature remains relatively unchanged when titania content increases. Vickers microhardness measurements used in this study allowed us to understand the contribution of the inorganic part (phase TiO2) to the mechanical properties of the polymer. The creep of hybrids has been studied carrying out hardness measurements under various indentation times. The mineral constituent leads to an important increase of the hardness and limits, in a significant way, the creep of polymer.

Rheo-Optics Studies in the Development of Hybrid Liquid Crystalline Based Mwir Polarizers

1999 ◽  
Vol 559 ◽  
Author(s):  
P.T. Mather ◽  
W. Barnes ◽  
P.J. Hood ◽  
T.J. Bunning
Keyword(s):  
Liquid Crystalline ◽  
Flow Behavior ◽  
Optical Microscope ◽  
Processing Technique ◽  
Strain Rates ◽  
Alignment Layer ◽  
Small Pitch ◽  
Wide Range ◽  
Measured Polarization ◽  
Free Films

ABSTRACTWe present here a rheo-optical study of the flow behavior of two cholesteric liquid crystals, one with a large pitch and one with a small pitch. The large pitch compound has been investigated as a possible fixed wavelength polarizer in the mid-wavelength infra-red region (3-5 micron). The investigation of these compounds is driven by their low melt viscosity and ability to vitrify order, and thus functionality, into films with a wide range of thickness. In our attempts to obtain consistent thin films with reproducible contrast ratios, we explored the defect textures of both compounds under a polarizing optical microscope. These materials were sheared at various strain rates and at various temperatures in an attempt to determine the best processing window for defect free films. The pitch lengths of the two materials investigated were 160 and 1330 nm. The flow behavior of the large pitch material resembles a pure nematic with defect refinement taking place under flow. The short pitch material exhibited the typical Grandjean oily streaks upon shearing followed by coarsening. Observations made during this rheological study were used to identify a processing technique for the large pitch materials. Upon application of a conventional buffed alignment layer, films with consistent quality were routinely made. The measured polarization contrast of >70:1 exceeds the values obtained from state-of-the art commercial polarizers in this wavelength regime.

scholarly journals Permeability studies of Damar Batu free films for transdermal application

2009 ◽  
Vol 15 (2) ◽  
pp. 83-88 ◽  
Author(s):  
Atish Mundada ◽  
Jasmine Avari
Keyword(s):  
Tensile Strength ◽  
Moisture Absorption ◽  
Chloroform Solution ◽  
Polyethylene Glycol 400 ◽  
Permeability Characteristics ◽  
Zero Order Kinetics ◽  
Transdermal Application ◽  
Model Drug ◽  
Free Films ◽  
Permeability Studies

Damar Batu (DB) looks like stone with black or dark brown color inside. Due to its film forming ability it is used in the manufacture of paper, wood, varnishes, lacquers, polishes and additives for beverages. In the present study the permeability of free films of DB casted from chloroform solution containing different plasticizers was studied with a view to developing a suitable rate controlling membrane for transdermal use. The free films of DB were prepared by a mercury substrate technique and dibutyl sebacate (DBS), dibutyl phthalate (DBP), polyethylene glycol 400 (PEG400) and propylene glycol (PG) were tried as plasticizers. DB films were then evaluated for uniformity of thickness, moisture absorption, water vapour transmission, tensile strength, percentage elongation and folding endurance. Permeability characteristics of free films of DB were studied using diltiazem hydrochloride (DH) as a model drug. Little variation in film thickness ensured the uniformity of the films. DBS produces tough DB films with more tensile strength. Drug diffusion through the free films followed zero order kinetics. The films plasticized with PEG400 showed higher permeability for DH compared with other films. The order of decrease of permeability of plasticized films with plasticizers was PEG400 > PG > DBP > DBS. Diffusion of drugs through the free films of DB was extended over a longer period of time at a controlled rate. DB seems to be a promising rate controlling membrane for the transdermal application.

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