WVTR Value Research Articles

PENGARUH PENAMBAHAN LILIN LEBAH DAN NANOPARTIKEL SENG OKSIDA TERHADAP SIFAT FISIK DAN MEKANIS FILM BERBASIS KITOSAN

Chitosan-based films showed good gel formation capability and gas permeability (CO2 and O2). However, the high permeability of water vapor limits the application of chitosan as a single coating material. Additionally, single chitosan film was also brittle, so the addition of lipid and metal nanoparticles were chosen to solve this problem. This research aimed to determine the effect of the addition of beeswax emulsion and zinc oxide nanoparticles (ZnO-NPs) on the physical and mechanical properties of chitosan based films. The film was prepared by dissolving ZnO-NPs (0, 1 and 2% by weight of chitosan) into 100 mL of distilled water followed by the addition 1 g of chitosan and or, addition of beeswax emulsion (0 and 5% by the volume of solution). The result showed that the addition of beeswax emulsion ZnO-NPs into chitosan based film significantly decreased WVTR value from 24.03 to 10.38 g/m2 hours and the tensile strength value from 8.30 to 6.92 Mpa. The addition of beeswax emulsion and ZnO-NPs also changed the physical properties of chitosan-based film significantly; in terms appearance, color and thickness. Mean-while, the film elongation percentage changed significantly in the range of 30.36 to 50.09 % when ZnO-NPs was added into chitosan-based film solution. Overall, the addition of beeswax and ZnO-NPs showed improvement of the physical and mechanical properties of chitosan-based films so that better packaging of fresh food products can be developed.

P‐2: Effect of Buffer Layer on Performance and Reliability of Flexible a‐IGZO TFTs Fabricated on Colorless Polyimide of G4.5

A series of gas barrier films on colorless polyimide substrates are studied at G4.5 backplane. The performances of barrier layer and TFT are identified by the film‐forming temperature, film structure, reliabilities, NBTIS and WVTR. The use of a SiNx‐SiOx (100nm–500nm) at PECVD temperature 285/295 °C resulted in the best light transmittance and reliabilities, and the electrical properties of a‐IGZO TFTs on glass is better than on cPI. The WVTR value of the SiNx‐SiOx (100nm–500nm) barrier layer on cPI are calculated to be 8.5×10−5 g/(m2‐day) at 37.8°C/100% RH, the NBTIS are improved after LLO and are deterioration after WVTR test. It is believed that the moisture and hydrogen diffusion from the underlying layers including cPI and environment atmosphere can be effectively suppressed by SiNx‐SiOx (100nm–500nm) barrier, and a flexible array backplane is demonstrated by means of these methods.

The Effect of Temperature Variation on the Yield Edible Film of Canna Starch (Canna edulis Kerr) Modified by Aloe Vera (Aloe vera L) with Addition of Purple Cabbage (Brassica oleracea) Anthocyanin Pigment as Bioindicator

Edible films are made from canna tuber starch, glycerol, aloe vera gel, and addition of purple cabbage extract (Brassica oleracea) aimed to determine the effect of temperature variation on the results of edible film synthesis and anthocyanin effectivenes s of purple cabbage as a pH indicator. The stages in this study include isolation of canna tuber starch, extraction of purple cabbage, making aloe vera gel, determination of anthocyanin extract proportions, synthesis of edible films with varied temperatures, and characterization of edible film results. Optimal composition of cabbage extract as a pH bio-indicator is used for synthesis of edible film with temperature variations between 75-90oC and elongation of 26.6% and WVTR value of 4.750 g/m2h at 85oC.

Effect of different type of clay on water barrier properties of Starch Composite

In the present report, effect of different type of clay on water barrier properties of starch composite has been investigated. The starch was from cassava, and the clays of 23 % (w/w) were cloisite Na, cloisite 15A, nanofil 116 and PGV. Clay and starch composites were prepared by using solution casting by mixture at 80 °C, stirred for 60 minutes, then put in the oven for 12 hours at 40 °C. The films were characterized by payne cup analysisis (water vapour transmission rate - WVTR), X-ray diffraction (XRD) and Fourier Transform Infra Red (FTIR). The WVTR values showed that the best water barrier properties improvement of the composites when Cloisite-Na was added to starch. The XRD showed that intercalated nanocomposites were formed in the Cloisite-Na/starch, while microcomposites were formed when Cloisite 15A, PGV, and Nanofill clay were added to starch. Strong interaction between starch and Cloisite was also shown by FTIR.

Characterization of Edible Film from Starch of Taro (Colocasia esculenta (L.) Schott) with Addition of Chitosan on Dodol Substituted Seaweed (Eucheuma cottonii L.)

Abstract.Edible film is a thin layer to protect food which it can be consumed. One of the main components to make edible film is starch, which could be derived from taro tubers. Taro tubers contain high starch content about 70-80% which consists of 5.55% of amylose and 74.45% of amylopectin with yield reach to 28.7%. However, the weakness of starch-based edible film are low resistance to water and low barrier properties to water vapor. One of the recommended hydrophobic biopolymers to improve the film characteristics of starch as well having antimicrobial activity is chitosan. The objectives of this research are to know the interaction and influence of starch concentration from taro tuber and concentration of chitosan on physical and mechanical character of edible film, including thickness, density, transparency, tensile, elongation and water vapor transmission eate (WVTR). The best treatment from first objective will apply on dodol (food made by glutinous rice) substituted by seaweed to know the effect of its application on dodol shelf life (texture analysis, weight loss and microbiology). Therefore this research was conducted in 2 stages and 2 experimental design methods. The first stage was the process of making edible film using Randomized Block Design method and the second stage was the application of edible film using Random Design Complete method. The results of physical and mechanical analysis of edible film based on its effect on the storage of dodol showed that the best treatment was obtained of P3K3 treatment (6% of Taro starch: 3% of Chitosan), P3K1 (6% of Taro starch: 1% of Chitosan) and P3K2 (6% Taro starch: 2% of Chitosan). The application of 3 types of edible films based on the best treatment of dodol substitute of seaweed has significant effects on the value of weight loss, texture and total plate count during the storage period. Effectiveness of edible film in inhibiting damage to dodol was obtained of P3K3 treatment (6% of Taro starch: 3% of Chitosan) with WVTR value equal to 0.189 g / cm2 hour, 0.170 N / mm2 of tensile strength, 0.088% of elongation, 0.160 mm of thickness, 0.151 of density and 0.000 mm-1of transparency.

Design of Highly Water Resistant, Impermeable, and Flexible Thin-Film Encapsulation Based on Inorganic/Organic Hybrid Layers

The lack of a transparent, flexible, and reliable encapsulation layer for organic-based devices makes it difficult to commercialize wearable, transparent, flexible displays. The reliability of organic-based devices sensitive to water vapor and oxygen must be guaranteed through an additional encapsulation layer for the luminance efficiency and lifetime. Especially, one of the major difficulties in current and future OLED applications has been the absence of thin-film encapsulation with superior barrier performance, mechanical flexibility, and water-resistant properties. In this work, we fabricated highly water-resistant, impermeable, and flexible inorganic/organic multilayers with optimized Al2O3 and functional organic layers. The key properties of the fabricated multilayers were compared according to the thickness and functionality of the inorganic and organic layers. Improvement of the barrier performance is mainly attributed to the optimized thickness of the Al2O3 films, and is additionally due to the increased lag time and effective surface planarization effects caused by the use of micrometer-thick organic layers. As a result, the 3-dyad multilayer structure composed of 60 nm-thick Al2O3 layers deposited at 70 °C and 2-μm-thick silane-based inorganic/organic hybrid polymer (silamer) layers with layered silica exhibited the lowest WVTR value of 1.11 × 10-6 g/m2/day in storage conditions of 30 °C/90% relative humidity. In addition, the multibarrier exhibited good mechanical stability through the use of alternating stacks of brittle inorganic and soft organic layers, without showing a large increase in the WVTR after bending tests. In addition, silamer layers improved the environmental stability of the Al2O3 ALD film. The silamer layer coated on the Al2O3 film effectively worked as a protective layer against harsh environments. The effective contact at the interface of Al2O3/silamer makes the barrier structure more impermeable and corrosion-resistant. In this study, we not only demonstrated an optimized multilayer based on functional organic layers but also provided a methodology for designing a wearable encapsulation applicable to wearable organic electronics.

Efficient multi-barrier thin film encapsulation of OLED using alternating Al2O3 and polymer layers.

Organic optoelectronic devices, especially for OLEDs, are extremely susceptibility to water vapor and oxygen which limit their widespread commercialization. In order to extend the shelf-lifetime of devices, thin film encapsulation is the most promising and challenging encapsulation process. In this study, dyad-style multilayer encapsulation structures based on alternating Al2O3 layer and parylene C have been discussed as gas diffusion barriers, in which dense and pinhole-free Al2O3 films were grown by atomic layer deposition (ALD) and flexible parylene C layers were deposited by chemical vapor deposition (CVD). We found the particle in ALD deposited Al2O3 films process is the key killer to barrier property. The thickness of Al2O3 films is the key factor which limit the amount of strain placed on barrier films. With three dyads of the optimal thickness of 30 nm Al2O3 film and 500 nm parylene C, WVTR value is lower than 10−5 g m−2 per day. In addition, the lifetime of OLEDs with and without encapsulation was 190 h and 10 h, respectively. All the results show that this TFE structure has the effective encapsulated property and does not cause degradation of the OLED devices.

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.

Improving the gas barrier property of SiOx:C thin films deposited by RF magnetron sputtering

This study focuses on the SiOx:C thin films on polyethyleneterephtalate (PET) produced by radio-frequency (RF) magnetron sputtering with hexamethyldisiloxane (HMDSO). Silicon atoms are inserted into SiOx:C thin films using a silicon target to improve the gas barrier property. Since inserting Si atoms into SiOx:C thin films can reduce the number of pores and increase the density of the film. This process has two benefits. First, it can be easily combined with sputtering processes to produce a multilayer film; and second, it can be performed at low pressures (~10−1Pa) to improve the quality of the plasma polymer film. A more linear-like structure and a less cage-like structure is associated with higher density of SiOx:C thin films. The average transmittance of the films thus obtained exceeds 91% in the wavelengths of visible region, and the lowest water vapor transmission rate achieves 0.076g/m2/day. It is about one fourth of the optimum WVTR value (0.3g/m2/day) of a single layer of SiOx:C thin film fabricated with HMDSO at present.

Ellipsometric Porosimetry and Electrochemical Impedance Spectroscopy Characterization for Moisture Permeation Barrier Layers

In this work the combination of ellipsometric porosimetry (EP) and electrochemical impedance spectroscopy (EIS) is extensively addressed in order to characterize the nano‐porosity and further elucidate its influence on the water permeation properties of plasma enhanced‐CVD SiO2 layers. Pores with diameter in the range of 0.27–0.6 nm are studied by adopting a multi‐solvent/multi‐ion approach, with EP and EIS, respectively. This combined study has brought to conclude that open pores larger than 0.42 nm are responsible for WVTR values in the range of 10−3‐10−5 gm−2 day−1, while pores with diameter between 0.42–0.27 nm were found to drive the transition to excellent moisture barrier layers (10−6 gm−2 day−1). Moreover, it is shown that EIS is capable of detecting macro‐scale defects, next to nano‐porosity, being thus a powerful tool for the analysis of moisture barrier layers.

10.1: Invited Paper: Flexible OLED using Plastic Barrier Film and its Roll‐to‐Roll Manufacturing

AbstractFor the expansion of OLED lighting business, it is very important for OLED to differentiate itself from conventional lighting source. One of the merits of OLED device is the capability to be formed on flexible substrates, such as plastic, metal foil and thin glass. Especially, plastic barrier film can bring high level of flexibility, which could not be achieved by any conventional lighting method.In this paper, barrier film with various WVTR value, including 10−6 ‐order, was applied and the conditions to have very little or almost no dark spot growth under 85°C85% high temperature / humidity test are shown. Flexible OLED panels are manufactured with world's first roll‐to‐roll equipment using plastic barrier film.

Physical Characterisation of an Alginate/Lysozyme Nano-Laminate Coating and Its Evaluation on ‘Coalho’ Cheese Shelf Life

This work aimed at the characterisation of a nano-laminate coating produced by the layer-by-layer methodology and its evaluation on the preservation of ‘Coalho’ cheese. Initially, five alternate layers of alginate and lysozyme were assembled in an aminolysed/charged polyethylene terephthalate (A/C PET) and physically characterised by UV/VIS spectroscopy, contact angle, water vapour (WVTR) and oxygen (OTR) transmission rates and scanning electron microscopy. Afterwards, the same methodology was used to apply the nano-laminate coating in ‘Coalho’ cheese and its shelf life was evaluated during 20 days in terms of mass loss, pH, lipid peroxidation, titratable acidity and microbial count. UV/VIS spectroscopy and contact angle analyses confirmed the layers’ deposition and the successful assembly of nano-laminate coating on A/C PET surface. The coating presented WVTR and OTR values of 1.03 × 10−3 and 1.28 × 10−4 g m−2 s−1, respectively. After 20 days, coated cheese showed lower values of mass loss, pH, lipidic peroxidation, microorganisms’ proliferation and higher titratable acidity in comparison with uncoated cheese. These results suggest that gas barrier and antibacterial properties of alginate/lysozyme nanocoating can be used to extend the shelf life of ‘Coalho’ cheese.

Hydrophobic modification of cellulose fibres by cationic-modified polyacrylate latex with core-shell structure

In cellulose fibre-based green packaging, the poor resistance or barrier against water or water vapour has remained as one of the key challenges. In this work, cationic polymer latex, butyl acrylate-co-styrene/2-ethylhexylacrylate-co-methyl methacrylate (BA-co-St/EHA-co-MMA), with core-shell structure was especially synthesized and used as a wet-end additive to render the fibre or paper hydrophobic. TEM observation confirmed that the latex particles obtained indeed possessed desired characteristic of core-shell structure. The experimental results showed that the cationic polymer was especially suitable for use in papermaking processes due to its high retention with cellulose fibres. The surface modification of the natural fibre by the adsorption of cationic latex on the fibre surfaces potentially created the thin films of polymers on fibre surfaces. The resulting paper is highly hydrophobic with improved barrier property, as demonstrated by the high contact angles and relatively low WVTR value. Moreover, the mechanical properties of paper were maintained or even improved in the presence of an appropriate level of the latex.