Significantly Improved High-Temperature Energy Storage Performance of BOPP Films by Coating Nanoscale Inorganic Layer

Biaxially oriented polypropylene(BOPP)is one of the most commonly used commercial capacitor films,but its upper operating temperature is below 105℃due to the sharply increased electrical conduction loss at high temperature.In this study,growing an inorganic nanoscale coating layer onto the BOPP film's surface is proposed to suppress electrical conduction loss at high temperature,as well as increase its upper operating temperature.Four kinds of inorganic coating layers that have different energy band structure and dielectric property are grown onto the both surface of BOPP films,respectively.The effect of inorganic coating layer on the high-temperature energy storage performance has been systematically investigated.The favorable coating layer materials and appropriate thickness enable the BOPP films to have a significant improvement in high-temperature energy storage performance.Specifically,when the aluminum nitride(AIN)acts as a coating layer,the AIN-BOPP-AIN sandwich-structured films possess a discharged energy density of 1.5 J cm^(-3)with an efficiency of 90%at 125℃,accompanying an outstandingly cyclic property.Both the discharged energy density and operation temperature are significantly enhanced,indicating that this efficient and facile method provides an important reference to improve the high-temperature energy storage performance of polymer-based dielectric films.

Edible Coatings Based on Apple Pectin,Cellulose Nanocrystals,and Essential Oil of Lemongrass:Improving the Quality and Shelf Life of Strawberries(Fragaria Ananassa)

In this work,nine different types of edible coating based on pectin,cellulose nanocrystals,glycerol,and essential oil of lemongrass were prepared and used to coat strawberries with a film formed directly on the surface of the coated fruit.The effects of the different edible coatings on refrigerated fruits in terms of weight loss,titratable acidity,total soluble solids,pH,and anthocyanin content was evaluated after 2 days,4 days,6 days,and 8 days of storage.Application of the edible coatings reduced the weight loss of the coated strawberries and the anthocyanin content.The total soluble solids content of or uncoated fruit increase more markedly than that of coated fruit.In contrast,pH was maintained for both coated and uncoated strawberries.The edible coatings were effective in minimizing of the weight loss,without worsening the physical chemistry attributes.The treatments T5 and T9 presented the best results.

Preparation and Characterization of Alumina Membranes on Capillary Supports： Effect of Film-coating on Crack-free Membrane Preparation

Ceramic capillary membrane has received much attention due to its relatively high pack density and favorable mechanical strength.However,it is difficult to prepare capillary membrane on its thin support by a dip-coating method.In this study,alumina microfiltration membranes were prepared on the inner surface of alumina capillary support(outer diameter 4 mm,inner diameter 2.5 mm)by a dip-coating method.Scanning electron microscopy(SEM)observation,gas bubble pressure(GBP)method and membrane permeation test were carried out to evaluate membrane performance.Two major effects in preparation of crack-free membrane,capillary filtration and film-coating,upon the thin support were studied.The as-prepared crack-free membrane presents a narrow pore size distribution,a mean pore size of about 0.6μm and a high pure water flux of 86000 L·m -2 ·h -1 ·MPa.It is proved that the membrane thickness should be sufficiently large to overcome the defects of support surface,but it is only one of the prerequisites for the formation of crack-free membrane.Furthermore,it is demonstrated that the capillary filtration effect is greatly restricted for thin capillary support with the dip-coating method and the film-coating effect plays a crucial role in the formation of crack-free membrane.

Interfacial Interaction Between Polyurethane/Poly(Methacrylateco-Styrene) Coating and the Regenerated Cellulose Film

Water-resistant films were prepared by coating the surface of regenerated cellulose films with castor oil-based polyurethane (PU)/ poly-(methacrylate-co-styrene) [P (MA-St)]. The effects of the ratio of PU to P (MA-St) copolymer on tensile strength (dry and wet states), vapor permeability, size stability, and water resistivity of the coated films were studied. The interfacial interaction between cellulose and the PU/P (MA-St) coating was analyzed using infrared (IR), ultraviolet (UV), scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential thermal analysis (DTA), and electron probe microanalysis (EPMA). The results indicated that the mechanical properties and water resistivity of the coated films significantly enhanced, and the biodegradability was displayed, when the ratio of PU to P (MA-St) was 8∶2 by weight. The chemical bonds and hydrogen bonds between the cellulose, PU, and the copolymer exist in the coated films. It is regarded that PU/P (MA-St) semi-interpenetrating polymer networks (IPNs) were formed, and a shared network of PU with both the cellulose and the coating in the coated film occurred simultaneously resulting in a strong bonding between the coating layer and the film.

Biopolymer Films and Coatings in Packaging Applications--A Review of Recent Developments

This review covers the recent developments in the field of biobased packaging materials. Special emphasis is placed on the barrier properties, which are crucial in terms of food packaging. The state-of-the-art of several biopolymers including pectin, starch, chitosan, xylan, galactoglucomannan, lignin and cellulose nanofibrils is discussed. As in most cases the packaging related properties of single layer biopolymer films are inadequate, the thin film coatings, such as sol-gel and ALD (atomic layer deposition), as well as the multilayer coatings are also briefly touched.

THE CURING THEORY OF SILlCONE PAINT AND THE STRUCTURE OF COATING FILM

This paper puts forward the two methods of weightlessness and alkoxyl group content determination to calculate the amount of cross-linking agent after elaborating the curing essence of silicone paint under the action of catalysis , and provides the theoretical basis of fixing the amoount of cross-linking agent accurately and quantitatively. At the same time, the structure of coating film is studied by the use of photoelectronic spectromenter and some other modern technology, and verified in theory. At last, this paper analyses the layer structure and the relationship between it and the coating properties.

Preparation of CuInSe_2 thin films by paste coating

Precursor pastes were obtained by milling Cu-In alloys and Se powders. CulnSe2 thin films were successfully prepared by precursor layers, which were coated using these pastes, and were annealed in a H2 atmosphere. The pastes were tested by laser particle diameter analyzer, simultaneous thermogravimetric and differential thermal analysis instruments （TG-DTA）, and X-ray diffractometry （XRD）. Selenized films were characterized by XRD, scanning electron microscopy （SEM）, and energy dispersive spectroscopy （EDS）. The results indicate that chalcopyrite CuInSe2 is formed at 180℃ and the crystallinity of this phase is improved as the temperature rises. All the CuInSe2 thin films, which were annealed at various temperatures, exhibit the preferred orientation along the （112） plane. The compression of precursor layers before selenization step is one of the most essential factors for the preparation of perfect CuInSe2 thin films.

Carbon Film Coating Used in CdZnTe Crystal Growth

A simple method of carbon film coating used in CdZnTe crystal growth was developed. The optimum parameters were selected. Breakdown of carbon film was commonly seen if Cd reservoir was not used in the crystal growth. The carbon film was in good condition when the vapor pressure of Cd was kept around 0.1 MPa during crystal growth.

Thin film dynamics in coating problems using Onsager principle

A new variational method is proposed to investigate the dynamics of the thin film in a coating flow where a liquid is delivered through a fixed slot gap onto a moving substrate. A simplified ODE system has also been derived for the evolution of the thin film whose thickness hf is asymptotically constant behind the coating front. We calculate the phase diagram as well as the film profiles and approximate the film thickness theoretically, and agreement with the well-known scaling law as Ca2/3 is found.

Effect of substrate curvature on thickness distribution of polydimethylsiloxane thin film in spin coating process

The polymer spin coating is critical in flexible electronic manufaction and micro-electro-mechanical system（MEMS）devices due to its simple operation, and uniformly coated layers. Some researchers focus on the effects of spin coating parameters such as wafer rotating speed, the viscosity of the coating liquid and solvent evaporation on final film thickness.In this work, the influence of substrate curvature on film thickness distribution is considered. A new parameter which represents the edge bead effect ratio（re） is proposed to investigate the influence factor of edge bead effect. Several operation parameters including the curvature of the substrate and the wafer-spin speed are taken into account to study the effects on the film thickness uniformity and edge-bead ratio. The morphologies and film thickness values of the spin-coated PDMS films under various substrate curvatures and coating speeds are measured with laser confocal microscopy. According to the results, both the convex and concave substrate will help to reduce the edge-bead effect significantly and thin film with better surface morphology can be obtained at high spin speed. Additionally, the relationship between the edge-bead ratio and the thin film thickness is like parabolic curve instead of linear dependence. This work may contribute to the mass production of flexible electronic devices.

Preparation and optical properties of Nb-NbN multilayer films as solar selective absorptive coatings

Based on the cermet double layer structure, Nb-NbN multi-layer films for solar selective coatings were deposited by direct current reactive magnetron sputtering. The Nb/Nb-NbN/Al2O3 trilayered structure was deposited on a stainless steel (SS) substrate by using a single niobium target. The expected components were adjusted by changing the gas flowing ratios of Ar: N2. The Al2O3 antireflective layer on the top of the film was produced by r. f. magnetron sputtering using Al2O3 ceramic target. A solar absorptivity of 0.94 and a normal emissivity of 0.16 at room temperature have been achieved for the coating. Thermal vacuum aging to the samples was carried out at 350 and 500 ℃ for 1 h. The results show a good thermal stability. Microstructure and its dependence on temperature of the Nb, NbN and Nb-NbN single layers were investigated, respectively.

Antioxidant Capacity and Bioaccessibility of Synergic Mango (cv. Ataulfo) Peel Phenolic Compounds in Edible Coatings Applied to Fresh-Cut Papaya

Edible coatings (EC) applied to fresh-cut fruits are used to increase their shelf-life and to deliver antioxidant bioactives such as phenolic compounds (PC) that reduce their oxidative damage while enhance their functional value. However, the combination of different PC may have synergetic, additive or antagonic effects on the final antioxidant capacity (AOXC). The aim of this study was to examine the AOXC of binary combinations of selected PC from mango peel and their bioaccessibility from 6% alginate-based EC applied to fresh-cut papaya, under simulated gastrointestinal conditions. Among equimolar (0.1 mM) combinations, gallic + protocatechuic acids (AB) were synergic in radical scavenging activity (RSA) as assayed by DPPH (90% RSA) and FRAP (0.39 mg TE/mL) methods;when assayed in 6% alginate-based EC, their RSA increased (117.85% RSA, 0.88 mg TE/mL). The application of EC + AB to papaya cubes and further in vitro digestion decreased their AOXC probably due to interactions between EC and papaya’s matrix. Therefore, further studies are needed in order to evaluate the effect of combination of phenolic and EC applied in other fruits matrix on antioxidants bioaccessibility.

Bicomponent Solutions of Food Polysaccharide and Edible Films on Their Basis

The study of the rheological properties of aqueous solutions of corn starch (CS) blends with sodium alginate (SA) and agar-agar (AA) as well as the physical and mechanical properties of bicomponent films on their basis has been carried out. The data show that adding of both polymers to starch solution causes an increase in viscosity which is higher in the case of SA. Activation energy for viscosity flow of solutions of CS blended with SA has minimum value at CS:SA ratio = 98:2. The above mentioned dependence is not typical for AA, as flow activation energy in this case raises steadily with the growth of AA content in the solution, like viscosity of the CS:AA. The extreme behavior of polymer blends with low content of one of the polymers is described in terms of mutual solubility or thermodynamic compatibility. There is a tendency that mechanical properties and water solubility increase with the increasing of SA and AA polymers in corn starch matrix. Obtained data evidence the benefits of bicomponent films production instead of starch-based films.

Effect of Antimicrobial Edible Films on the Sensory and Physical Properties of Organic Spinach in Salad Bags

The effects of antimicrobial edible films containing carvacrol and cinnamaldehyde on organic baby spinach were determined via sensory analysis and changes in physical properties. Edible films made from pulp of hibiscus, apple, or carrot containing carvacrol or cinnamaldehyde at 0.5%, 1.5%, or 3% concentrations were added to organic baby spinach in plastic bags. These bags were stored at 4°C for 20-24h before performing sensory evaluation and measuring changes in physical properties. A randomized block design with an affective test was used. Preference liking was evaluated based on a 9-point hedonic scale for aroma, color, freshness, mouthfeel, flavor, and overall acceptability. Additionally, panelists quantified each sample using a 5-point hedonic scale for pungency, browning, bitterness, off-odor, and sourness. The color and texture of spinach samples were measured. Edible films containing cinnamaldehyde had the highest preference liking based on aroma, color, freshness, mouthfeel, flavor, and overall acceptability than those containing carvacrol and were the most likely to be purchased by panelists;therefore, cinnamaldehyde can potentially be used as an alternative sanitization option. There were no significant (p ≤ 0.05) changes in firmness or color values between spinach treated with antimicrobial films and controls. The results provide the produce industry with options for incorporating antimicrobial films into salad bags without influencing the physical or sensory properties of baby spinach.

Development of hyaluronic acid-based edible film for alleviating dry mouth

For alleviating dry mouth symptoms,edible films based on hyaluronic acid(HA)with 3 different m(800,1200 and 2300 kDa)were prepared(800 F,1200 F and 2300 F,respectively),and the properties as well as effectiveness were compared.The concentration of each HA dispersion for film forming was set as 3.0%,1.5%or 1.0%,for the m800,1200 and 2300 kDa,respectively,based on the solubility.The 800 F showed the highest thickness,tensile strength,and water vapor transparency,whereas obtained the lowest transparency and elongation at break among samples.All of the HA films showed safety against microorganism during 28 storage day at 40℃with 60%humidity.The optimum site for film attachment in mouth was the palate,and800 F was the most effective for stimulating saliva secretion,eliciting a 38%increase compared to control(without film),tested by the elderly over 65 years old.By the sensory test,800 F was also the most acceptable.Based on above results,the edible films effectively stimulating saliva secretion could be produced with HA,and the physical,sensory characteristics as well as disintegration times of the film could be controlled by mand the dissolution concentration of HA.

Influence of hydroxypropyl methylcellulose edible coating on fresh-keeping and storability of tomato

The effect of application of cellulose-based edible coating, hydroxypropyl methylcellulose (HPMC) to mature-green tomatoes on the firmness and color was investigated. Tomatoes were stored at 20℃ for up to 18 days. Firmness decreased as storage time increased in all treatments. However, application of HPMC edible coating delayed softening of tomatoes during 18 days of storage at 20℃ . At days 7, 13 and 18,the firmness of tomatoes coated with HPMC was significantly ( P ≤ 0.05) greater than the firmness of uncoated tomatoes. The study also confirmed that HPMC coatings could significantly (P≤0.05) delay the changes in color of tomatoes stored at 20℃ . The ripening of tomatoes from the pink stage to the red stage was successfully retarded. HPMC coating could extend the shelf life of fresh tomatoes. The retardation of the rate of loss of firmness could reduce the economic loss that would result from spoilage by mechanical injury during transportation of tomatoes.

Numerical Simulation of the Thin Film Coating Flow in Two-Dimension

Thin film coating is a process of making liquid film cover and deposit base body surface by the way of dipping, spraying, sliding or spin coating, which is a kind of modern surface engineering. It plays an important role in the actual processing, such as improving the surface properties, fine processing, and new surface properties. Analysis of the influence of substrating morphology and fluid flow properties itself on coating fluid motion has an important significance to optimize the thin film coating and improve the quality of the final film. The influence from uneven substrate surface’s geometry configuration on internal motion of the flow field in slip-coating is analyzed by using the FLUENT software as a calculation platform. A two-dimension model of slip coating under isosceles triangle and isosceles trapezoid substrate was established, and thin film coating fluid motions under different configuration parameters were simulated. It is pointed out that the key factor determining the turbulence generation and evolution is the parameter of substrating surface nature. The effects of the change of Reynolds number on turbulent appearance and action area are studied. The velocity contours of fluid field on different substrate surfaces are shown, and the impact of substrate geometry on the backwater region is analyzed.

Nucleation and growth behavior of coating film on Mg–Al–Zn alloy with different surface topographies via plasma electrolytic oxidation

This work was made to investigate how nucleation and growth behavior of the coating film were affected by surface topographies of Mg–Al–Zn alloy substrate during the initial stage of plasma electrolytic oxidation(PEO).To satisfy this end,a single substrate was prepared by mechanical treatment exhibiting rough and smooth regions with an equal area on the surface.The rough region with prominent hills and grooves induced the breakdown of passive film,which was indicated by an early appearance of plasma discharge on the rough region since nucleation of coating film occurred preferentially around the hills.However,the coating film grown on the grooves was somewhat thicker and more porous than the film grown on the hills and smooth regions.This was due to the fact that the growth of the coating film was found to be localized in the presence of rough region,which was in line with the discharge activities.Herein,the nucleation and growth behavior during the initial stage of PEO will be discussed schematically on the basis of microstructural interpretation.

Rheological Properties of Casting Solutions for Starch Edible Films Production

Rheological properties of corn starch and sodium alginate blend solutions have been measured at different polymer ratios in the temperature range from 303 to 343 K bya R/S Brook field rheometer with аcoaxial cylinder measuring unit. Dynamic viscosity of blends has been shown to decrease with shear rate increase and to increase with sodium alginate content increase. The influence of shear rate on activation energy of viscous flow depends on sodium alginate content and is different for below and over 5% (mass) content. Applicability of Ostwald-de-Waele, Herschel-Bulkley, Bingham and Casson models for the description of CS:SA blend solutions flow has been analyzed. Rheological properties of CS:SA blend solutions allow one to look at them as an alternative to starch solutions for edible films casting and production by dry method.