Water Vapor Transmission Rate Properties Research Articles

KARAKTERISTIK EDIBLE FILM YANG DIHASILKAN DENGAN BAHAN DASAR PEKTIN KULIT BUAH KOPI ROBUSTA DAN GLUKOMANAN

Coffee peel is a by-product of coffee processing, which is about 50-60%. The coffee peel has pectin content ranging from 27.20 to 57.24%. One of the utilization of this pectin wa s used as a raw material for an edible film. Pectin-based edible films ha d advantages, including good tensile strength and water vapor transmission rate properties . On the other hand, edible film pectin ha d weaknesses: hard, brittle, and low in elongation, so it wa s necessary to add other ingredients, such as glucomannan and sorbitol, to correct these weaknesses. This study aim ed to determine the best characteristics of the edible film of Robusta coffee skin pectin with glucomannan and the addition of sorbitol. This research wa s an experimental method using a completely randomized design method with two factors: the ratio of pectin: glucomannan 1:4, 2:3, and 3:2; addition of sorbitol 1.5 ml, 3 ml, and 4.5 ml. The observed variables included the thickness, solubility, and water vapor transmission rates. D ata of thickness, solubility, and water vapor transmission rate were analyzed using analysis of variance and further tested by the Duncan Multiple Range Test at a 5% level. The selected treatment for producing the edible film from pectin of coffee peel and glucomannan was R3K1 . T he characteristics of the edible film produced were a thickness value of 0.11 mm, solubility of 72.3%, water vapor transmission rate of 5,77 gram/m2, the tensile strength of 2.05 Mpa, and elongation of 13.71%.

Water vapor transmission rate property of SiNx thin films prepared by low temperature (

We used an inline system equipped with a linear plasma enhanced chemical vapor deposition (L-PECVD) source available at low temperatures for the thin film encapsulation of flexible organic light emitting diode displays. This inline system can be used for coating on a moving substrate, which can increase productivity than a cluster system with the typical PECVD source. In this paper, we report the excellent water vapor barrier properties of SiNx films deposited on PEN film substrates at low temperatures process using the L-PECVD source. The SiNx thin film was deposited using silane (SiH4), ammonia (NH3) and helium (He) gases. The SiNx thin film deposited by L-PECVD showed good results for pinhole, grain boundary, stress, wet etch which are defects that can affect the lifetime of the OLED. The moisture permeation characteristics of the optimized SiNx thin films were finally measured using a MOCON's WVTR measuring instrument and WVTR values lower than the detection limit of the measuring device (less than 5.0 × 10−5 g/m2·day) were obtained. Based on these results, SiNx deposited using the L-PECVD is considered a good candidate for TFE (Thin Film Encapsulation) application of flexible OLEDs.

Evaluation extracellular matrix-chitosan composite films for wound healing application.

The present study describes the preparation of extracellular matrix (ECM; from porcine omentum) based chitosan composite films for wound dressing applications. The films were prepared by varying the ECM content, whereas, the amount of chitosan was kept constant. The interactions amongst the components of the films were analyzed by FTIR and XRD studies. The films were thoroughly characterized for surface hydrophilicity, moisture retention capability, water vapor permeability, mechanical and biocompatibility. FTIR study indicated that both chitosan and ECM were present in their native form and did not lose their activity. XRD analysis suggested composition dependent change in the crystallinity of the films. The mechanical properties suggested that the composite films had sufficient properties to be used for wound dressing applications. An increase in the ECM content resulted in better hydrophilicity of the films and hence better the moisture retention capacity and retardant water vapor transmission rate property of the composite films. The films were found to be biocompatible to both blood and adipose tissue derived stem cells. In gist, the prepared films may be explored as wound dressing materials.

Combination of high-pressure treatment, mild heating and holding time effects as a means of improving the barrier properties of gelatin-based packaging films using response surface modeling

Abstract The optimum combination of high-pressure (HP), mild temperature application and holding time on pigskin-derived, gelatin-based, film-forming solutions to improve the barrier properties of packaging films was determined using response surface methodology. Results showed that the variable response oxygen transmission rate (OTR) decreased significantly using a combination of temperature, time, and the interaction between pressure and time. The determined optimum conditions to minimize the OTR were high pressure treatment (600 MPa) and holding time (30 min), while maintaining the temperature at 20.5 °C. In parallel, films obtained at the optimum conditions (OPT) were characterized for structural, thermal, mechanical, water vapor transmission rate (WVTR) and color properties. OPT films were significantly affected by mechanical (TS), thermal (Tm), WVTR properties and redness a* values compared to untreated control samples. Overall, a combination of HP, mild temperature and holding time on film-forming solutions showed interesting potential in altering film characteristics, especially in the enhancement of barrier properties. Industrial relevance Results obtained in this study are of considerable importance for the film development and the shelf-life of food products packaged in films treated with the methodology used in the current work. The oxygen permeation through the film packaging can lead to a degradation of the quality attributes of the food products influencing microbial development as well chemical and enzymatic degradation pathways. Oxygen is responsible for oxidative rancidity of unsaturated fats with the development of undesirable flavors and aromas and a loss in vitamin C. The package oxygen permeability plays a key role in affecting the internal partial pressure of a packaging system and for this reason the oxygen permeability is probably the property mostly tested for the different packaging materials. Within this contest, the industrial relevance of this study is significant, since the results showed a potential application of a combination of high-pressure, mild treatment and holding time to increase barrier properties in bio-sourced packaging films thus extending the shelf-life of foodstuffs.

Preparation and characterization of thermally stable polyimide membranes by electrospinning for protective clothing applications

The aim of the present study was to obtain high-performance materials for heat and flame protective clothing. Therefore, hybrid membranes were prepared using Kevlar as support and aromatic polyimide nanofibers as a protective coating. The exceptional performances of the prepared membranes were highlighted by selected indicators: high thermal stability, fire resistance and improvement in air permeability without modifying drastically the water vapor transmission rate properties. Attenuated total reflectance Fourier transform infrared and 1H nuclear magnetic resonance spectroscopy were employed to confirm polyimide formation. The ability of polyimide to form fibers was investigated by rheological measurements and scanning electron microscopy, respectively. Thermal degradation was studied using thermogravimetric analysis and a microscale combustion calorimeter. The transport properties of the materials were examined by air permeability, water vapor transmission rate and water resistance. It was shown that transport properties of the modified Kevlar membranes could be controlled by varying the spinning time of polyimide solution. Moreover, by annealing the modified Kevlar weavings at 260℃, the structural integrity and transport properties were not affected, whereas a higher resistance to water was found.

Gas diffusion barrier characteristics of Al2O3/alucone films formed using trimethylaluminum, water and ethylene glycol for organic light emitting diode encapsulation

Al2O3/alucone barrier films were deposited by using atomic layer deposition and molecular layer deposition at 85 °C. Fourier transform infrared spectroscopy spectra reveal that the chemical bonding states, such as those of O–H, C–H, and C–O groups, changed rapidly in alucone films because the water vapor may absorb and/or react with the alucone film. The water vapor transmission rate (WVTR) measured by the calcium test of alucone film was similar to that of polyethylene naphthalate. However, the hybrid Al2O3/alucone films (2.08×10−2g/m2day) show better WVTR properties than that of Al2O3 single layer (3.73×10−2g/m2day) or that of alucone (1.14g/m2day). Hybrid layers can drastically improve the water vapor diffusion barrier property because the alucone layer may increase the water vapor diffusion path in the film and decrease the diffusion speed by trapping water vapor chemically. These promising hybrid layers can create a synergy effect to improve not only the WVTR property but also the flexible property.

Improving the gas barrier properties of a-SiOxCyNz film at low temperature using high energy and suitable nitrogen flow rate

Amorphous silicon oxycarbonitride thin films were synthesized on polyethylene terephthalate (PET) substrates at low temperatures (∼80 °C) by plasma-enhanced chemical vapor deposition (PECVD). A high ion flux and suitable nitrogen flow rate improved the gas barrier properties and deposition rate of the resulting a-SiOxCyNz film. The a-SiOxCyNz films were deposited at a high deposition rate and low water WVTR properties as a result of the high ion flux and nitrogen chemistry. The high ion flux modified the chemical structure and nitrogen atomic composition of the resulting a-SiOxCyNz film coatings. The substrate temperature was characterized using a thermometer. In addition, the coating properties were characterized by Fourier transform infrared (FT-IR), X-ray photoelectron spectroscopy (XPS) and the water vapor transmission rate (WVTR).

Si–O barrier technology for bacterial cellulose nanocomposite flexible displays

Si–O thin film was successfully deposited on bacterial cellulose nanocomposite via plasma enhanced chemical vapor deposition (PECVD) as transparent barrier against water vapor. X-ray photoelectron spectroscopy (XPS) confirmed consistent Si and O atomic concentrations through the entire depth of the Si–O layer. The Si–O layer had uniform and highly smooth surface – more than 80% of the surface features the surface roughness of 15nm. The water vapor transmission rate (WVTR) of the bacterial cellulose nanocomposite was evaluated as 9×10−2g/m2/day, but after the deposition of the Si–O barrier layer, the WVTR in the range of 10−4g/m2/day was achieved. The WVTR property of the nanocomposite can be further adjusted through the operating parameters of PECVD. These properties indicated the quality of the Si–O film as an effective water vapor barrier. Bacterial cellulose nanocomposite deposited with Si–O barrier film can be useful as substrate for flexible organic light emitting diode (OLED) displays.

Si3N4박막의 유기발광소자 수분침투 방지막으로의 응용

In this paper, we studied WVTR(water vapor transmission rate) properties of thin film that was deposited using TCP-CVD (transformer coupled plasma chemical vapor deposition) method for the possibility of OLED(organic light emitting diode) encapsulation. Considering the conventional OLED processing temperature limit of below , the thin films were deposited at room temperature. The thin films were prepared with the process conditions: and , as reactive gases; working pressure below 15 mTorr; RF power for TCP below 500 W. Through MOCON test for WVTR, we analyzed water vapor permeation per day. We obtained that WVTR property below 6~0.05 gm//day at process conditions. The best preparation condition for thin film to get the best WVTR property of 0.05 gm//day were gas flow rate of 10:200 sccm, working pressure of 10 mTorr, working distance of 70 mm, TCP power of 500 W and film thickness of 200 nm. respectively. The proposed results indicates that the thin film could replace metal or glass as encapsulation for flexible OLED.