scholarly journals Stability of Film-Forming Dispersions: Affects the Morphology and Optical Properties of Polymeric Films

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1464
Author(s):  
Maria Gabriela De Paola ◽  
Rosy Paletta ◽  
Catia Giovanna Lopresto ◽  
Giuseppe Emanuele Lio ◽  
Antonio De Luca ◽  
...  
Keyword(s):  
Optical Properties ◽  
Phase Separation ◽  
Food Packaging ◽  
Uv Light ◽  
Ultra Violet ◽  
Dispersed Phase ◽  
Significant Information ◽  
Film Forming ◽  
Light Protection

Starch-based films are promising alternatives to synthetic films in food packaging. They were widely studied in terms of mechanical and optical properties. In food packaging, optical properties are of great interest because ultra violet (UV-light) protection is strictly required. Nevertheless, the characterization of film-forming dispersions was poorly addressed, especially regarding its correlation with the film produced. In this work, we characterized film-forming dispersions at different compositions of starch and carboxymethyl cellulose (CMC) by Turbiscan. This instrument is based on multiple light scattering and gives significant information about the miscibility of polymers in the dispersed phase. Indeed, it identifies the phenomena of destabilization and phase separation before their visibility to the unaided eye. This work aimed to study whether the homogeneous/inhomogeneous morphology of films could be forecast by the analysis of profiles obtained in the dispersed phase. The films produced were investigated by optical microscopy and absorbance analysis. As the CMC fraction increased, Turbiscan showed reduced phase separation. This implies better miscibility of mixture components and higher gelification degree. The related film was more homogeneous and presented higher UV absorbance. Consequently, film-forming dispersions and optical properties of films are strictly correlated and Turbiscan-based analysis is very useful to investigate the dispersion stability and predict the film quality.

Bioactive chitosan/ellagic acid films with UV-light protection for active food packaging

2017 ◽  
Vol 73 ◽  
pp. 120-128 ◽  
Author(s):  
Carla Vilela ◽  
Ricardo J.B. Pinto ◽  
Joel Coelho ◽  
Maria R.M. Domingues ◽  
Sara Daina ◽  
...  
Keyword(s):  
Ellagic Acid ◽  
Food Packaging ◽  
Uv Light ◽  
Active Food Packaging ◽  
Light Protection

Characterization of Phase Separation in Film Forming Biopolymer Mixtures

2005 ◽  
Vol 6 (2) ◽  
pp. 932-941 ◽  
Author(s):  
Maria Petersson ◽  
Niklas Lorén ◽  
Mats Stading
Keyword(s):  
Phase Separation ◽  
Film Forming

Characterization of UV-Peroxide Killing of Bacterial Spores

2003 ◽  
Vol 66 (7) ◽  
pp. 1233-1240 ◽  
Author(s):  
JEFFREY S. REIDMILLER ◽  
JEREMIAH D. BALDECK ◽  
GLEN C. RUTHERFORD ◽  
ROBERT E. MARQUIS
Keyword(s):  
Uv Irradiation ◽  
Food Packaging ◽  
Uv Light ◽  
Bacterial Spores ◽  
Experimental Conditions ◽  
Hydrogen Peroxide Treatment ◽  
Spore Killing ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Copper Cations

Advantage is taken in many sterilization processes, especially for food packaging materials, of the synergy between H2O2 and UV irradiation for spore killing. The nature of the synergy is currently not well defined in terms of targets and mechanisms. We found that under some experimental conditions, the synergistic killing of spores of Bacillus megaterium ATCC 19213 appeared to be mainly UV-enhanced peroxide killing, while under other conditions, it appeared to be mainly peroxide-enhanced UV killing. Lethal combinations of H2O2 and UV irradiation for spores resulted in only modest increases in auxotrophic mutations among survivors, indicative of little DNA damage, in contrast to higher mutation levels after dry-heat damage at 115°C. However, the combination of UV light and peroxide did lead to major inactivation of glucose 6-phosphate dehydrogenase, an enzyme that was used to monitor the damage to bacterial protein. Synergistic UV-H2O2 killing was reduced by agents such as pyruvate, thiosulfate, and iron or copper cations, which appeared to act at least in part by reacting chemically with H2O2, and was only slightly affected by the use of UV light at a wavelength of 222 nm rather than 254 nm. Hydrogen peroxide treatment can precede UV irradiation for synergistic killing by some hours with an interim of drying for spores of Bacillus subtilis A, a spore type used commonly for the validation of aseptic processes. Synergistic killing of dried spores or those in suspensions was accelerated at higher temperatures (50°C) rather than at lower temperatures (25°C).

scholarly journals Preparation and Characterization of κ-Carrageenan Modified with Maleic Anhydride and Its Application in Films

Marine Drugs ◽  
2021 ◽  
Vol 19 (9) ◽  
pp. 486
Author(s):  
Yuan Zhou ◽  
Fu-Quan Chen ◽  
Si Chen ◽  
Qiong Xiao ◽  
Hui-Fen Weng ◽  
...  
Keyword(s):  
Maleic Anhydride ◽  
Uv Light ◽  
Barrier Properties ◽  
Water Contact ◽  
Elongation At Break ◽  
Gelling Temperature ◽  
Film Forming ◽  
The Fourier Transform ◽  
Property Changes

In this work, the physicochemical properties of maleic anhydride (MAH)-modified κ-carrageenan (κCar) (MC) were characterized and compared with those of native κ-carrageenan (NC). The Fourier transform infrared spectrum of MC exhibited that κCar was successfully modified. Thermogravimetric analysis indicated that the thermal stability of MC was decreased. When the degree of substitution was 0.032, MC exhibited a low gel strength (759 g/cm2), gelling temperature (33.3 °C), and dehydration rate (60.3%). Given the excellent film-forming ability of κCar, MC films were then prepared and were found to have better mechanical and barrier properties (UV and water) than NC films. With regard to optical properties, MC films could completely absorb UV light in the range of 200–236 nm. The water contact angle of MC films was higher than that of NC films. Moreover, the elongation at break increased from 26.9% to 163%. These physicochemical property changes imply that MC can be employed in polysaccharide-based films.

Fabrication and characterization of polycarbonate-silica filaments for 3D printing applications

2021 ◽  
pp. 002199832110447
Author(s):  
Deepa Kodali ◽  
Chibu O Umerah ◽  
Mohanad O Idrees ◽  
S Jeelani ◽  
Vijaya K Rangari
Keyword(s):  
Optical Properties ◽  
3D Printing ◽  
Uv Light ◽  
Tensile Tests ◽  
Filler Loading ◽  
Ease Of Use ◽  
Potential Candidate ◽  
Low Concentrations ◽  
3D Printed

Owing to its robustness, ability to achieve complex geometries, and ease of use, 3D printing has become one of the noteworthy applications in the field of engineering. Polycarbonate has become a thermoplastic of interest due to its excellent mechanical and optical properties. Especially when infused with nanosilica, polycarbonate becomes a potential candidate for 3D printing with enhanced properties. Polycarbonate nanocomposite filaments infused with AEROSIL (nanosilica) have been melt extruded with various filler loadings of 0.5, 1, and 3 wt% and are then 3D printed. The thermal analysis of the filaments has shown that thermal stability of the filaments increases with increase in filler loading. Tensile tests have shown that addition of nanosilica have enhanced the mechanical properties of the filaments as well as 3D printed films. The addition of silica in low concentrations exhibit higher transmittance of UV light, as silica restricts the mobility of polycarbonate. Despite 3D printing causing voids in bulk materials, silica at low concentration (0.5 and 1 wt%) can improve the mechanical and optical properties. These improvements are promising for applications in thin film interfaces and the automotive industry.

Physico-chemical Characterization of Edible Packaging Film Supplemented with Ocimum (Tulsi) Essential oil

2021 ◽  
Vol 37 (2) ◽  
pp. 362-367
Author(s):  
Simranpreet Kaur ◽  
Chayanika Putatunda
Keyword(s):  
Essential Oil ◽  
Food Packaging ◽  
Uv Light ◽  
Chemical Characterization ◽  
Zone Of Inhibition ◽  
Adverse Health Effects ◽  
Physico Chemical ◽  
Edible Packaging ◽  
Total Moisture Content

The concern about the possible adverse health effects of plastic based food packaging as well as the environmental pollution caused by plastics has lead to efforts in looking for alternative, eco-friendly and biocompatible food packaging materials. In the present investigation, a composite edible film was prepared from whey, pectin and gelatin, which was supplemented withOcimum essential oil. These films were characterized for thickness, transparency towards visible and UV light, and total moisture content. Antimicrobial activity of these films were examined against Escherichia coli MTCC 118, Pseudomonas aeruginosa MTCC 741, Staphylococcus aureus MTCC 96, Bacillus cereus MTCC 1272and Pseudomonas fluorescens MTCC 103. The film activity was found to bemaximumagainst B. cereus with 8 mm zone of inhibition on addition of 6% of Ocimum essential oil. The films were also active against all other pathogens except P. aeruginosa.

Preparation and Characterization of Transparent, Photoluminescent MgAl2O4:Eu2+ Ceramics

2014 ◽  
Vol 69 (2) ◽  
pp. 159-164 ◽  
Author(s):  
Katja Waetzig ◽  
Isabel Kinski
Keyword(s):  
Optical Properties ◽  
Uv Light ◽  
Hot Isostatic Pressing ◽  
Argon Atmosphere ◽  
Nitrate Salt ◽  
Sintering Process ◽  
Conventional Sintering ◽  
Sintering Conditions ◽  
Spinel Powder

The influence of 0.1 mol-% Eu2+ doping in a transparent MgAl2O4 ceramic on the optical properties has been investigated. The goal was to prepare first an Eu3+-doped spinel by a conventional sintering process for a transparent ceramic followed by a reductive densification step yielding an Eu2+-doped product. Commercially available spinel powder was doped with 0.1 mol-% europium using a nitrate salt and afterwards compacted into green bodies. In the following process the specimens were pre-sintered and post-densified using hot isostatic pressing (HIP) in an argon atmosphere. The transparency of the disks was measured optically using UV/Vis and fluorescence spectroscopy. After optimization of the sintering conditions the resulting Eu2+-doped spinel showed a transparency of 77:4% and a conversion of the UV light with a wavelength of 260 nm into blue light with a wavelength of 450 nm.

Optical properties of a thin layer of the Vanadium dioxide at the metal state

2015 ◽  
Vol 9 (1) ◽  
pp. 2303-2310
Author(s):  
Abderrahim Benchaib ◽  
Abdesselam Mdaa ◽  
Izeddine Zorkani ◽  
Anouar Jorio
Keyword(s):  
Optical Properties ◽  
Thin Layer ◽  
Vanadium Dioxide ◽  
Ultra Violet ◽  
Index Of Refraction ◽  
Cost Of Energy ◽  
Infra Red ◽  
Metal State ◽  
The Cost ◽  
Reversible Phase

The vanadium dioxide VO₂ currently became very motivating for the nanotechnologies’ researchers. It makes party of the intelligent materials because these optical properties abruptly change semiconductor state with metal at a critical  temperature θ = 68°C. This transition from reversible phase is carried out from a monoclinical structure characterizing its semiconductor state at low temperature towards the metal state of this material which becomes tétragonal rutile for  θ ˃ 68°C ; it is done during a few nanoseconds. Several studies were made on this material in a massive state and a thin layer. We will simulate by Maple the constant optics of a thin layer of VO₂ thickness z = 82 nm for the metal state according to the energy ω of the incidental photons in the energy interval: 0.001242 ≤ ω(ev) ≤ 6, from the infra-red (I.R) to the ultra-violet (U.V) so as to be able to control the various technological nano applications, like the detectors I.R or the U.V,  the intelligent windows to  increase  the energy efficiency in the buildings in order to save the cost of energy consumption by electric air-conditioning and the paintings containing nano crystals of this material. The constant optics, which we will simulate, is: the index of refraction, the reflectivity, the transmittivity, the coefficient of extinction, the dielectric functions ԑ₁ real part and  ԑ₂  imaginary part of the permittivity complexes ԑ of this material and the coefficient absorption. 

Optical properties of the Vanadium dioxide

2015 ◽  
Vol 8 (2) ◽  
pp. 2148-2155 ◽  
Author(s):  
Abderrahim Benchaib ◽  
Abdesselam Mdaa ◽  
Izeddine Zorkani ◽  
Anouar Jorio
Keyword(s):  
Energy Efficiency ◽  
Optical Properties ◽  
Critical Temperature ◽  
Thin Layer ◽  
Dielectric Function ◽  
Vanadium Dioxide ◽  
Ultra Violet ◽  
Index Of Refraction ◽  
Practical Utility ◽  
Infra Red

The vanadium dioxide is a material thermo chromium which sees its optical properties changing at the time of the transition from the phase of semiconductor state ↔ metal, at a critical temperature of 68°C. The study of the optical properties of a thin layer of VO₂ thickness 82 nm, such as the dielectric function, the index of refraction, the coefficient ofextinction, the absorption’s coefficient, the reflectivity, the transmittivity, in the photonic spectrum of energy ω located inthe interval: 0.001242 ≤ ω (ev) ≤ 6, enables us to control well its practical utility in various applications, like the intelligentpanes, the photovoltaic, paintings for increasing energy efficiency in buildings, detectors of infra-red (I.R) or ultra-violet(U.V). We will make simulations with Maple and compare our results with those of the literature

Sign in / Sign up

Export Citation Format

Share Document