Hybrid Films Research Articles

Biocompatible Hybrid Graphenic Thin Coatings on Flexible Substrates through Matrix-Assisted Pulsed Laser Evaporation (MAPLE).

This work reports the production of biocompatible thin layers for biomedical applications based on a graphene-like material (GL), a graphene-related material (GRM) obtained from carbon black. GL was combined in a hybrid fashion with polydopamine (pDA), a mussel-inspired water-resistant wet adhesive bonding obtained by the oxidative polymerization of dopamine (DA), and polyvinyl pyrrolidinone (PVP), a nontoxic synthetic polymer with intrinsic adhesion properties, to obtain a tighter adhesion of the thin layer to the substrate (silicone slices). Matrix-assisted pulsed laser evaporation (MAPLE) was used to coat PDMS slices with thin films of GL-pDA and GL-PVP directly from their frozen suspensions in water. The results indicate that the relevant chemical-physical characteristics of both thin films (evidenced by FTIR and AFM) were maintained after MAPLE deposition and that the films exhibit uniformity also at the nanometric level. After deposition, the GL-pDA and GL-PVP films underwent a biological survey toward murine fibroblasts (NIH3T3), human keratinocytes (HaCAT), and human cervical adenocarcinoma epithelial-like (HeLa) cells to assess the feasibility of this approach. Results indicate that both the GL-pDA and GL-PVP films did not perturb the biological parameters evaluated, including cytoskeleton alterations. Both hybrid films enhanced the effects of GL on cellular vitality across all cell lines. Specifically, the GL-pDA film exhibited a more stable effect over time (up to 72 h), whereas the GL-PVP film behaved similarly to the GL film in NIH3T3 and HeLa cell lines after long-term exposure. These promising results make the GL-pDA and GL-PVP films potential candidates for the manufacture of coated flexible devices for biomedical applications.

Synthesis and Characterization of ZnO and TiO2 Hybrid Coatings for Textile UV Anti-Aging Protection.

The aim of this study was to prepare and characterize thin hybrid films on polyurethane-coated knitted fabrics and to achieve satisfactory color fastness to artificial light. Sol-gel-derived hybrid thin films were deposited via the dip-coating of 3-glycidoxypropiltrimethoxysilane. Titanium dioxide (TiO2) and zinc oxide (ZnO) nanopowders were added to compensate for the insufficient aging resistance, which manifests itself in low color fastness and is one of the most frequent complaints from manufacturers of coated marine fabrics (yachts, boats, etc.). The optimum processing conditions were determined by varying the concentration of precursors and auxiliaries, the mass concentration of TiO2 and ZnO nanopowders, the drawing speed, and the methods and process of fabric treatment. The hybrid films were also characterized using scanning electron microscopy and Fourier transform infrared spectroscopy with attenuated total internal reflection, while Spectraflash SF 300 investigated color fastness. After 300 h of exposure in a xenon chamber, the thin hybrid films showed good color fastness and good resistance to washing cycles. The sol-gel treatment proved to be a successful answer to the manufacturers' need for the post-treatment of polyurethane-coated knitted fabrics against UV radiation for use in the marine sector (yachts, speedboats, etc.).

Highly Thermally Conductive Flexible Environmentally Friendly Hybrid Film Based on Natural Sericin-Boron Nitride

Highly Thermally Conductive Flexible Environmentally Friendly Hybrid Film Based on Natural Sericin-Boron Nitride

Effect of Embedded g-C3N4 Nanosheets on the Hydration and Thermal Response Behavior of Cross-Linked Thermoresponsive Copolymer Films.

The effect of embedded graphitic carbon nitride (g-C3N4) nanosheets on hydration and thermal response behavior of cross-linked thermoresponsive poly(di(ethylene glycol) methyl ether methacrylate-co-oligo(ethylene glycol) methyl ether methacrylate), abbreviated as P(MA-co-MA300), thin films is probed by white light interferometry. Compared with that of the cross-linked pure P(MA-co-MA300) films, the surface roughness of the cross-linked hybrid films is slightly increased, which is caused by the minor aggregation of g-C3N4 nanosheets during the spin-coating process. After exposure to a water vapor atmosphere, both cross-linked pure and hybrid films can absorb water and swell. However, the introduction of g-C3N4 not only induces a larger hydration extent but also triggers a nonlinear transition behavior upon heating. This prominent difference might be related to the residual hydrophilic groups (-NH2 and N-H) on the surface of g-C3N4 nanosheets, which enhance the interaction and absorption capability for water molecules in the hybrid films. Upon further increasing the amount of embedded g-C3N4 nanosheets in films, more hydrogen bonds are formed and a larger hydration extent of films is observed. To break all of the hydrogen bonds in films, a higher transition temperature (TT) is required. The observed hydration and transition behaviors of hybrid films can be used to design hydrogel-based films for hydrogen evolution or wastewater treatment.

Preparation and Printing Performance of Visible Light Photochromic Paper Based on PMoA-PWA/ZnO/PVP Composite

The recyclable paper based on photochromic materials not only reduces the pollution in the paper manufacture process, but also reduces the pollution caused by the use of ink, which receives wide attention. In this paper, a series of phosphomolybdic acid–phosphotungstic acid/ZnO/polyvinylpyrrolidone (PMoA-PWA/ZnO/PVP) hybrid films, which had different ratio of PMoA/PWA, was prepared by the ultrasonic composite method. The results indicated that the hybrid film prepared when the ratio of PMoA to PWA was 3 had the best photochromic performance. In this system, ZnO was the photosensitizer, while PMoA/PWA was the chromophore. The photochromic mechanism of the PMoA-PWA/ZnO/PVP hybrid film was based on the photogenerated electron transfer mechanism. ZnO generated photoelectron under the excitation of visible light, then PMoA and PWA obtained the photoelectron and produced photoreduction reaction to generate heteropolyblue. The visible light photochromic paper was prepared by loaded PMoA-PWA/ZnO/PVP hybrid film (A3) on A4 paper. Application tests showed that the prepared paper had extremely stable, excellent and reversible visible light photochromic properties, whether it was printing patterns or words, and could replace ordinary paper to realize the reuse of paper.

Impacts of graphene quantum dots on the optical, electrical and thermal properties of the archetypal conducting polymer PEDOT:PSS

We investigated the optical properties and thermal conductivity of blade-coated graphene quantum dots (GQDs)/PEDOT:PSS hybrid thin films by varying the content of GQDs. The optical properties were determined by spectroscopic ellipsometry in the range of 1.2–5.5 eV. Two dispersion models were used to analyze the optical properties of the films: the Bruggeman effective medium approximation (BEMA) for the hybrid films, and the Drude model combined with a Lorentzian oscillator for both the pure and the hybrid films, which provides insight into their electrical properties. As a novel finding, we observed that the optical anisotropy of PEDOT:PSS (Aldrich 483095) films is reduced after incorporating GQDs. Moreover, dedoping of the PEDOT chains is demonstrated upon increasing the content of GQDs within the hybrid films. Furthermore, the thermal conductivity shows a two-fold decrease as the GQDs fraction increases from 0 to 10 wt%. This result is understood considering that the GQDs act as local scattering centers, resulting in a decrease of the thermal conductivity.

Hybrid film cooling geometry analysis with OpenFOAM

Hybrid film cooling geometry analysis with OpenFOAM

An insect lac blanket-mimetic and degradable shellac hydrogel/chitosan packaging film with controllable gas permeation for fresh-cut vegetables preservation

Fresh-cut products are extremely perishable due to the processing operations, and the atmosphere environment, especially CO2, O2 and H2O, could profoundly affect their shelf life. Herein, an insect “lac blanket”-mimetic and facile strategy was proposed for fresh-cut vegetables preservation, employing porous shellac hydrogel microparticles as gas “switches” in chitosan film to regulate CO2, O2 and H2O vapor permeability. Thus, the shellac hydrogel/chitosan hybrid film presented the controllable and wide range of gas permeability, compared with the chitosan film. The shellac-COOH nanoscale vesicles aggregated to form shellac hydrogel network via hydrophobic binding. The shellac hydrogel microparticles played a certain lubricating effect on the hybrid film casting solution. The hydrogen bond network between shellac hydrogel and chitosan contributed to the excellent mechanical properties of the hybrid film. The hybrid film also exhibited remarkable water-resistant, antifogging properties, optical transparency and degradability. The hybrid packaging films prepared through this strategy could adjust the internal gas (CO2, O2, H2O and ethylene) contents within the packages, and further exhibited admirable preservation performance on three fresh-cut vegetables with different respiratory metabolisms. This gas permeation-controlled strategy has great potential in fresh food preservation and various other applications that need a modified atmosphere.

Preparation of Hybrid Films Containing Chitosan, Starch, Ascorbic Acid, and Different Metal Ions for Release of Doxorubicin

Preparation of Hybrid Films Containing Chitosan, Starch, Ascorbic Acid, and Different Metal Ions for Release of Doxorubicin

Eco-Friendly packaging film with integrated functions of High-Efficiency radiation cooling and Sustained-Release antimicrobial activity

The storage temperature and microbial contamination typically have significant impact on the deterioration rate and postharvest lifespan of fresh food. To meet the critical requirements of fresh food packaging, a hybrid functional packaging coating is developed by combing tannic acid (TA) as a binder, chitin nanofibers (CNF) as a crosslinker, and acidified halloysite nanotubes containing Apigenin (CA@e-HNTs) as an antimicrobial/cooling agent. The functional coating was sprayed on a poly(butylene adipate-co-terephthalate) (PBAT) substrate, integrating both radiative cooling capabilities and sustained antimicrobial properties. The hybrid film achieved subambient cooling through a high solar reflectance (90.5 %) and high mid-infrared emittance (94.0 %), resulting in a temperature of 6.2 ℃ below ambient under intense sunlight. When used for fresh food packaging, the hybrid functional film outperformed other commercially available food packaging materials in maintaining the quality of Agaricus bisporus and extending the storage time of fresh strawberries to 9 days. Moreover, the film exhibited excellent antibacterial and antioxidant properties. This zero-energy cooling technology with sustained antimicrobial characteristics has enormous potential for application in the preservation of fresh food, offering a more sustainable way to extend the shelf life of fresh produce and reduce food waste.

Transparent insulating photochromic PU/PTA films for Wide-Spectrum modulated smart windows

Photochromic materials have recently attracted widespread attention in the research of smart windows because they can function without additional devices. In this study, an innovative photochromic thermal insulating hybrid film based on a polyurethane matrix was prepared via a one-pot method, incorporating phosphotungstic acid. The film demonstrates excellent transparency, good mechanical strength, and a significant modulation of the solar spectrum, transitioning from colorless to dark blue under sunlight without the need for additional electron donors. This photochromic behavior is reversible and reproducible without degradation, resulting in a transmittance variation of up to 71 % at 550 nm, which is the most sensitive to the human eye, and more than 50 % modulating performance in 1800 ∼ 2500 nm. In addition, thermal insulation experiments proved that the smart window device prepared by the film could achieve a reduction of 9.3 °C under daylight. Overall, the photochromic films prepared using the one-pot method show good performance involving mechanical strength, efficient photochromic response, broad spectral range modulation, high coloring efficiency and cycling stability, and have promising applications in energy-saving buildings, anti-counterfeiting and smart displays.

Electrochemical Behaviour of (n‐Bu4N)4[AsVMo11O40] and (n‐Bu4N)4[AsV2Mo10O40] Doped PEDOT Film and Its Quartz Crystal Microbalance Studies

AbstractKeggin‐type polyoxometalates (POMs), (n‐Bu4N)4[AsVMo11O40] (AsVMo11) and (n‐Bu4N)4H[AsV2Mo10O40] (AsV2Mo10), have been immobilised with the conducting polymer poly (3,4‐ethylenedioxythiophene) (PEDOT) on the surface of the glassy carbon electrode via chronocoulometry technique. The voltammetric behaviour of these modified electrodes was investigated with cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). The resulting films showed the surface adsorbed behaviour and dependence on the pH of the electrolyte solution. By using AC impedance, it was found that the resulting POM‐doped PEDOT films were highly conductive. The redox switching stability of the polymer films was investigated, and it was found that the AsVMo11/PEDOT hybrid film is significantly more stable for continuous potential sweep than the AsV2Mo10/PEDOT hybrid film. Additionally, the EQCM measurements confirm that during the redox potential cycling, the anions in the supporting electrolyte replace the POMs anion doped onto the film.

Strategic design of degradable polyurethanes: Site-specific depolymerization, film-forming behavior, and reprocessability

This paper reports on the rational design of linear sustainable polyurethanes with on-demand depolymerization capabilities and film-forming properties. In this molecular approach, self-immolative urethane motifs are engineered to not only induce rapid degradation in response to an external stimulus via sequential elimination but also provide sufficient inter-chain interactions to yield nanofibers or free-standing films. Amalgamation with various isocyanate or polyol components results in a range of degradable polyurethanes, while doping with europium complexes or carbon black leads to the formation of free-standing hybrid films with photoluminescent or conductive properties, respectively. These films can be reversibly cast using a facile dissolution process, and the predetermined depolymerization products can then be used to generate upcycled materials such as polyurea or polyacrylate films. We believe that our conceptual design for sustainable polyurethanes can be advanced further when combined with conventional engineering techniques to meet industrial and environmental requirements and create desirable materials for contemporary applications.

Doped carbon dots reinforced flexible nanocomposite active polymer film for antibacterial and antioxidant activities

Utilizing nanoparticles in packaging materials has proven to be an effective method for enhancing the longevity and security of food products. Carbon dots (CDs) have a wide variety of potential applications in food packaging. A flexible film made of thermoplastic chitosan (TPC) and heteroatom-doped CDs has been created using a wet chemical blending technique. These CDs reinforced TPC based hybrid films exhibit flexibility, antioxidant properties, biodegradability, and resistance to UV radiation. The mechanical strength of the films was assessed through uniaxial tensile testing, while their low-temperature flexibility was evaluated by measuring the sub-ambient (∼-30°C) glass transition temperature (Tg). Additionally, the presence of CDs directly influences the permeability of oxygen and moisture, resulting in a reduction in comparison to neat chitosan films, a vital characteristic for packaging materials. Over a span of three weeks, the TPC-based hybrid films demonstrated a progressive weight loss (∼75 %), indicating their biodegradability. Furthermore, these films have shown promise as antibacterial and antioxidant materials. The durability of the films and the absence of chemical release from the embedded CDs within the TPC matrices were also verified, underscoring their considerable potential as antibacterial, biodegradable, and antioxidant packaging materials within the food industry.

Performance Improvement and Application of Degradable Poly-l-lactide and Yttrium-Doped Zinc Oxide Hybrid Films for Energy Harvesting.

Piezoelectric nanogenerators (PENGs) are booming for energy collection and wearable energy supply as one of the next generations of green energy-harvesting devices. Balancing the output, safety, degradation, and cost is the key to solving the bottleneck of PENG application. In this regard, yttrium (Y)-doped zinc oxide (ZnO) (Y-ZnO) was synthesized and embedded into polylactide (PLLA) for developing degradable piezoelectric composite films with an enhanced energy-harvesting performance. The synthesized Y-ZnO exhibits high piezoelectric properties benefiting from the stronger polarity of the Y-O bond and regulation of oxygen vacancy concentration, which improve the output performance of the composite film with Y-ZnO and PLLA (Y-Z-PLLA). The obtained open-circuit voltage (Voc), short-circuit current (Isc), and instantaneous power density of the optimized Y-Z-PLLA PENG reach 17.52 V, 2.45 μA, and 1.76 μW/cm2, respectively. The proposed PENG also shows good degradability. In addition, practical applications of the proposed PENG were demonstrated by converting biomechanical energy, such as walking, running, and jumping, into electricity.

Facile dip-coating of silk fibroin/tannic acid@CaCO3 hybrid film with superhydrophilicity on the surface of polypropylene nonwovens for oil–water separation

Superhydrophilic membrane materials are widely used for oil/water separation due to their excellent resistance to anti-fouling underwater. The key factors for realizing superhydrophilicity of membranes are the introduction of hydrophilic groups and the construction of surface micro/nano roughness structures. Herein, we propose a simple, mild, and green dip-coating method to prepare silk fibroin (SF)-tannic acid (TA)@CaCO3 hybrid film to achieve superhydrophilicity of polypropylene nonwovens (PP). Specifically, the hydrophobic interactions between SF and hydrophobic materials were used to create the pre-coatings. TA molecules were deposited onto the surface of SF via hydrogen bonding to provide phenolic hydroxyl groups for achieving the hydrophilicity of PP membranes. Then, the CaCO3 was synthesized in situ by introducing Ca2+ into the pre-coating while depositing TA to construct micro/nano-roughness structures on the PP membrane surface for obtaining superhydrophilicity. PP-SF-TA@CaCO3 membranes exhibit outstanding superhydrophilicity and underwater superoleophobicity, with separation efficiencies exceeding 99 % for a variety of oil–water mixtures and oil-in-water emulsions, and water fluxes ranging from 4000 L m-2h−1 to 5500 L m-2h−1. The separation efficiencies remained above 99 % throughout 50 separation cycles, indicating the excellent separation stability of the modified membranes. Moreover, no significant loss of separation efficiency was observed when separating oil mixtures from harsh water sources, including acidic, alkaline, cold, and hot water. Therefore, the membranes modified by the above process have a promising application in the practical separation of oily wastewater.

Hybrid films loaded with 5-fluorouracil and Reglan for synergistic treatment of colon cancer via asynchronous dual-drug delivery

Combination therapy with oral administration of several active ingredients is a popular clinical treatment for cancer. However, the traditional method has poor convenience, less safety, and low efficiency for patients. The combination of traditional pharmaceutical techniques and advanced material conversion methods can provide new solutions to this issue. In this research, a new kind of hybrid film was created via coaxial electrospraying, followed by a casting process. The films were composed of Reglan and 5-fluorouracil (5-FU)-loaded cellulose acetate (CA) core-shell particles in a polyvinylpyrrolidone (PVP) film matrix. Microscopic observations of these films demonstrated a solid cross section loaded with core-shell particles. X-ray diffraction and Fourier-transform infrared tests verified that the Reglan and 5-FU loaded in the films showed amorphous states and fine compatibilities with the polymeric matrices, i.e., PVP and CA, respectively. In vitro dissolution tests indicated that the films were able to provide the desired asynchronous dual-drug delivery, fast release of Reglan, and sustained release of 5-FU. The controlled release mechanisms were shown to be an erosion mechanism for Reglan and a typical Fickian diffusion mechanism for 5-FU. The protocols reported herein pioneer a new approach for fabricating biomaterials loaded with multiple drugs, each with its own controlled release behavior, for synergistic cancer treatment.

Physical properties of rutile-TiO2 Nanoparticles and effect on PVA/SiO2 hybrid films synthesized by sol-gel method

We use an ab-initio approach to analyze the structural, electronic band structure, and thermoelectric properties of titanium dioxide (TiO2 in rutile phase), and we then use rutile-TiO2 nanoparticles to determine its effects on sol-gel-produced polyvinyl alcohol/silicon dioxide (PVA/SiO2) hybrid films. The synthesis of hybrid films involved the incorporation of 1 % rutile-TiO2 nanoparticles in the PVA/SiO2 matrix. The thermoelectric properties of the resulting hybrid films were characterized by Seebeck coefficient measurements, as well as electrical and thermal conductivities. The synthesis of PVA/SiO2/Nano-TiO2 films was accomplished with success. The chemical bonds have amply demonstrated that the PVA backbone is connected to the (SiO2-TiO2) network. TGA testing indicates that hybrid films are more resistant to higher temperatures than pure PVA films. SiO2 nanoparticles reveal more effective loading to improve dielectric characteristics compared to TiO2. The best results are obtained in cases of mechanical, thermal and electrical insulation when both nanofillers are integrated into the polymer matrix. The findings show that the thermoelectric performance of PVA/SiO2 hybrid films is improved by the addition of (1 %) rutile-TiO2 nanoparticles in the rutile phase. This study provides insights into the potential applications of rutile-TiO2 nanoparticles in enhancing the thermoelectric properties of hybrid materials and opens up avenues for further research in this area, and contributes to the growing body of knowledge on enhancing the thermoelectric properties of materials by incorporating rutile-TiO2 nanoparticles into hybrid films synthesized by the sol-gel method.

Biofilms from poly-vinyl alcohol/palmyra root sprout with Boswellia serrata, carbon dots and anthocyanin for sensing the freshness of sardine fish

One of the main issues that customers worldwide have is food adulteration. In commercial packages, freshness cannot always be determined visually. Here, we propose sensitive films for use in food packaging that could alter colour to indicate a change in freshness. Hybrid, multifunctional, and eco-friendly films were prepared from polyvinyl alcohol/palmyra root sprout (PVA/PRS), fused with soy protein isolate carbon dot (CD), Boswellia serrata (BS), and Clitoriaternatea anthocyanin (CTE). The films showed pH sensitivity, antioxidant, and UV barrier properties. By creating hydrogen bonds between PRS and the other fillers, adding these substances makes PVA less crystallized. These interactions were verified by infrared Fourier-transform analysis. When compared to PVA, PRS films had significantly lower moisture content and swelling ratios. The UV-blocking capabilities of the films were greatly improved by the addition of CD, BS, and CTE without compromising their mechanical, thermal, or water vapor barrier properties. The composite film PVA/PRS/CD/BS/CTE exhibited a maximum tensile strength value of 69.47 ± 1.49 MPa. The CT extract provides the film with superior antioxidant properties. The colorimetric films PVA/PRS/CTE and PVA/PRS/CD/BS/CTE showed distinct pH-responsive colour-change properties as well as good colour stability. The colorimetric films were used to test the freshness of sardine fish, and they revealed unique colour changes that indicated whether the fish sample was spoiled or not.

Photoluminescent Nanocellulosic Film for Selective Hg2+ Ion Detection.

We developed a highly sensitive solid-state sensor for mercury detection by stabilizing red-sub-nanometric fluorescent gold nanoclusters (AuNC, 0.9 ± 0.1 nm diameter) with bovine serum albumin in a matrix composed of cellulose nanofibrils (CNF) (BSA-AuNC/CNF). The main morphological and optical features of the system were investigated via atomic force/transmission electron microscopy and UV-Vis/fluorescence spectroscopy. The hybrid film (off-white and highly transparent) showed strong photoluminescene under UV irradiation. The latter is assigned to the AuNC, which also increase the ductility of the emitting film, which was demonstrated for high sensitivity Hg2+ detection. When used as a sensor system, following AuNC printing on CNF hybrid films, a limit of detection <10 nM was confirmed. What is more, nanocellulose films have a high pore structure and selective separation properties, showcasing a wide range of potential applications in many fields such as water treatment and oil-water separation.