Hybrid Multilayer Films Research Articles

Intrinsically stretchable phototransistors with polymer-QD-polymer multi-layered hybrid films for visible-NIR perspective electronic skin sensors

Stretchable phototransistors represent a crucial component in the development of skin-inspired optoelectronics. Although there have been significant advancements in the development of skin-like photosensitive semiconductors, technology for stretchable phototransistors that can detect a broad spectrum of wavelengths from near-infrared (NIR) to visible light is still in its early stages. This study introduces an intrinsically stretchable phototransistor employing hybrid semiconductor films consisting of polymer semiconductors (PSC) and quantum dots (QDs). The hybrid multi-layered semiconductor film (PSC/QDs/PSC) possesses wide-ranging color sensitivity from NIR to visible light, along with high photosensitivity and photoresponsivity. Furthermore, our phototransistor exhibits remarkable strain-insensitive, photo-response characteristics, maintaining performance even under 50% strain and enduring 10,000 strain cycles. Notably, the phototransistor array, featuring a distinctive dodecagon shape of source/drain electrodes, effectively responds to NIR and visible light stimuli, even when subjected to substantial areal strains of up to 38%.

An “organic-inorganic” hybrid multilayer film for comprehensive support in soft and hard tissue regeneration after osteosarcoma resection

Three major complications often occur after osteosarcoma resection: large bone defects, infectious wounds, and tumor recurrence. In addition to conventional internal fixation and auto- or allografts, multifunctional supportive treatments are needed for limb reconstruction after tumor removal. With inspiration from the "organic-inorganic" hybrid concept, we developed a freestanding polyelectrolyte membrane (PEM) using a layer-by-layer (LBL) deposition of quaternized chitosan (QCS) and hyaluronic acid (HA), and with copper-doped laponite (CuLAP) intercalation. The CuLAP demonstrated photothermal conversion capabilities under near-infrared (NIR) light irradiation, and displayed glutathione (GSH)-depleted Fenton-like catalytic activity. The further engineered PEM possesses a "brick and mortar" structure with enhanced surface roughness and stiffness. The fusion of CuLAP-mediated GSH-depleted chemodynamic treatment (CDT) and moderate photothermal therapy (PTT) facilitated tumor ablation and bactericidal effects. Moreover, the continuous release of copper ions and silicates aided angiogenesis and osteogenesis, supporting the regeneration of both soft (skin) and hard (bone) tissues. This all-in-one platform offers a promising clinical tool for assisting tissue reconstruction after osteosarcoma resection.

Heterogeneous Ti3C2Tx MXene-MWCNT@MoS2 Film for Enhanced Long-Term Electromagnetic Interference Shielding in the Moisture Environment.

MXene, as a novel two-dimensional (2D) material, has unique inherent features such as lightweight, flexibility, high electrical conductivity, customizable surface chemistry, and facile solution processability. However, utilizing MXene (Ti3C2Tx) films for long-term electromagnetic interference (EMI) shielding poses challenges, as they are susceptible to chemical deterioration through oxidation into TiO2. In this work, an ultrathin heterogeneous film of Ti3C2Tx MXene integrated with multiwalled carbon nanotubes supporting MoS2 clusters (MXene/MWCNT@MoS2) was developed. The heterogeneous film with 15 wt % of MWCNT@MoS2 clusters exhibited improved EMI shielding performance such as the highest EMI shielding effectiveness of 50 dB and the specific shielding effectiveness of 20,355 dB cm2 g -1, mainly attributed to the excellent electrical conductivity, distinctive porous structure, and multiple interfacial interactions. The heterogeneous films underwent extended exposure to a moisture environment (35 days), and their structural stability and EMI shielding performance were enhanced by the integration of MWCNT@MoS2 clusters. As a result, the engineered heterostructure of multilayered hybrid films holds promise as a viable option for improving the EMI shielding effectiveness and stability of Ti3C2Tx MXene.

Expression of concern: Bacterial self-defense antibiotics release from organic-inorganic hybrid multilayer films for long-term anti-adhesion and biofilm inhibition properties.

Expression of concern for 'Bacterial self-defense antibiotics release from organic-inorganic hybrid multilayer films for long-term anti-adhesion and biofilm inhibition properties' by Qingwen Xu, Nanoscale, 2017, 9, 19245-19254, https://doi.org/10.1039/C7NR07106J.

Influence of structurally and morphologically different nanofillers on the performance of polysulfone membranes modified by the assembled PDDA/PAMPS-based hybrid multilayer thin film

A highly efficient nanofiltration membrane should exhibit high separation performance in removing divalent salts and organic solutes, as well as high permeation to meet practical separation and purification applications in aqueous media. Here, we designed a series of hybrid multilayer thin film membranes filled with the structurally and morphologically different nanofillers such as hexagonal boron nitride (HBN) nanosheets and metal-organic framework (MOF) nanoparticles, consisting of 3 and 6 layer pairs of polyelectrolyte through the layer-by-layer self-assembly technique (LBL) and characterized them in terms of dye and salt separation, as well as permeation. The rejection performance and permeability of the designed membranes manifested that HBN nanosheets were more effective than MOF nanoparticles in achieving a high-performance membrane. As compared to the bare multilayer thin film membrane, the addition of HBN nanosheets within the negatively-charged layers of the multilayer thin film membrane consisting of 6 bilayers resulted in good retention of up to 93% and 92% for acid blue (ACB) and bromophenol blue (BPB) dye molecules, respectively. Besides, this membrane exhibited 60% and 45% improvement in the water flux for ACB and BPB solutions, respectively, while the rejection of the sulfate ions maintained an acceptable value around 78%. Furthermore, it was found that this HBN-embedded hybrid multilayer membrane had superior potential for the removal of coherent foulant compared to all samples.

Yarn-ball-shaped CNF/MWCNT microspheres intercalating Ti3C2Tx MXene for electromagnetic interference shielding films

Ti3C2Tx MXenes with excellent metallic conductivity have proved promising in its application of electromagnetic interference (EMI) shielding. A hierarchical hybrid film with ultrathin thickness composed of Ti3C2Tx MXene layers embedded with yarn-ball-shaped microspheres of cellulose nanofibrils (CNF) and multiwalled carbon nanotube (MWCNT) was designed to improve the absorption of electromagnetic waves (EMWs). The addition of yarn-ball-shaped microspheres is to shield more EMWs via multiple reflections in the inner space and reduce the undesirable emissions into the air. After thermal annealing treatment, the ultrathin film with intercalation of the carbonized yarn-ball-shaped CNF/MWCNT microspheres exhibited enhanced EMWs absorption as an important part of shielding effectiveness (45.1±0.9 dB) as well as excellent mechanical stability (≈0.9 million bending times). Thus, the well-designed structure of multilayered hybrid films with intercalated conductive microspheres can be a good candidate for higher absorption in EMI shielding effectiveness and outstanding mechanical properties.

Two-dimensional superlattice-like sheets of superparamagnetic graphene oxide/magnetic nanoparticle hybrids

Using a simple and facile method, we precisely controlled the two-dimensional layered array structure of graphene oxide (GO)–iron oxide (Fe3O4) nanoparticle hybrid multilayer films and investigated the correlation between the assembled structure of the hybrid films and their magnetic properties. GO–Fe3O4 nanoparticle hybrids were obtained via the ligand exchange of oleic acid-functionalized Fe3O4 nanoparticles with GO at the gas–liquid interface. Hybrids of oriented Fe3O4 nanoparticles and GO monolayers spontaneously formed at the gas–liquid interface, which were subsequently deposited on solid substrates using the Langmuir–Schaefer (LS) technique. Two-dimensional superlattices of GO–Fe3O4 nanoparticle hybrids were fabricated through repeated LS deposition of the nanoparticle monolayer with a hexagonal array structure sandwiched between GO monolayers. The magnetic properties of the GO–Fe3O4 multilayer were measured using SQUID magnetometry. From the field cooling/zero field cooling results, we found that the 2D superlattice-like layered structure of the GO–Fe3O4 multilayer facilitates the layer-dependent properties in the out-of-plane field case due to the dipolar interactions between the top and bottom layers.

Highly sensitive flexible pressure sensors based on graphene/graphene scrolls multilayer hybrid films

In recent years, flexible pressure sensors have attracted much attention owing to their potential applications in motion detection and wearable electronics. As a result, important innovations have been reported in both conductive materials and the underlying substrates, which are the two crucial components of a pressure sensor. 1D materials like nanowires are being widely used as the conductive materials in flexible pressure sensors, but such sensors usually exhibit low performances mainly due to the lack of strong interfacial interactions between the substrates and 1D materials. In this paper, we report the use of graphene/graphene scrolls hybrid multilayers films as the conductive material and a micro-structured polydimethylsiloxane substrate using Epipremnum aureum leaf as the template to fabricate highly sensitive pressure sensors. The 2D structure of graphene allows to strongly anchor the scrolls to ensure the improved adhesion between the highly conductive hybrid films and the patterned substrate. We attribute the increased sensitivity (3.5 kPa \begin{document}$ ^{-1} $\end{document} ), fast response time ( \begin{document}$ 50 ms), and the good reproducibility during 1000 loading-unloading cycles of the pressure sensor to the synergistic effect between the 1D scrolls and 2D graphene films. Test results demonstrate that these sensors are promising for electronic skins and motion detection applications.

Oriented layered assemblies of graphene nanosheets/Fe3O4 nanoparticles as a superior anode material for lithium ion batteries

The development of more effective electrodes for lithium ion batteries requires increasing the specific surface area and improving the reversible capacity of the materials. We prepared a hybrid multilayer film consisting of graphene oxide (GO) nanosheets and iron oxide (Fe3O4) nanoparticles assembled using the Langmuir-Schaefer (LS) technique. The GO-Fe3O4 hybrid monolayer is formed by ligand exchange between GO suspended in the subphase and oleic acid-coated Fe3O4 nanoparticles dispersed at the liquid-gas interface. Transmission electron microscopy (TEM) and grazing incidence small angle X-ray scattering (GISAXS) results indicate that the GO-Fe3O4 composite monolayer at the interface possesses closely packed hexagonal structure of the Fe3O4 nanoparticles with high coverage upon monolayer compression. The multilayer GO-Fe3O4 hybrid materials were prepared by repeated LS deposition, exhibiting high reversible capacity (~600 mAh g−1) and superior cycle stability over 1000 cycles.

Hybrid Color-Tunable Polymer Light-Emitting Diodes Using Electrospraying.

This paper proposes a new paradigm in polymer light-emitting diode (PLED) fabrication by using a uniform electrosprayed microparticle film as the active layer. Among the seven electrospraying parameters analyzed, three crucial parameters are statistically identified and optimized to obtain thin electrosprayed microparticle layers. Using optimized electrospraying conditions, single-color red-emitting PLED (MEH-PPV) with a peak current density of 16.1 mA/mm2 under a 13.5 V bias and a peak external quantum efficiency of 3.2% are successfully fabricated. Finally, a combinatorial approach is implemented using both MEH-PPV (red-emitting) and F8BT (green-emitting) polymer microparticles at different mixing ratios to tune the emission spectrum of the devices. As such, it has been demonstrated that hybrid multilayer films using different organic materials with nonorthogonal solvents can be produced using this new approach. The parameter analysis and color-tunable properties pave the way towards white light PLED fabrication.

Hybrid multilayered films comprising organic monolayers and inorganic nanolayers for excellent flexible encapsulation films

In the present study, we develop novel hybrid multilayered films films composed of organic monolayers of 4-mercaptophenol (4MP) and inorganic Al2O3 nanolayers for thin film encapsulation. The 4MP/Al2O3 multilayered films films achieved an excellent transmittance (>90%) and an ultralow water vapor transmission rate (2.32 × 10−7 g m−2 days−1), even retained the excellent barrier properties in 1000 times bending process. Inhibition of pinhole propagation and resistance to mechanical strain from organic monolayers with the help of inorganic nanolayers brought to such superior barrier performance in flexible devices, which can enhance the lifespan of the organic electronic devices.

Transparent and Hybrid Multilayer Films with Improved Thermoelectric Performance by Chalcogenide-Interlayer-Induced Transport Enhancement.

Transparent thermoelectric thin films for efficient heat energy conversion can be extensively applied in healthcare and small electronics. We report a strategy for the fabrication of organic/inorganic hybrid multilayer films with improved thermoelectric performances. As an organic layer, a highly conductive poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) is deposited after a solvent treatment. An inorganic interlayer consisting of PEDOT-coated SnSeTe nanosheets (PEDOT-SnSeTe nanosheets) is introduced between the PEDOT:PSS layers to fabricate an alternately deposited PEDOT:PSS/PEDOT-SnSeTe nanosheets/PEDOT:PSS (PSP) multilayer film. To demonstrate the interlayer-induced thermoelectric behaviors, the thermoelectric properties and corresponding carrier transport properties of single-layer, bilayer, and multilayer films are investigated. The inorganic layer influences the intrinsic conduction toward a favorable value for an improved thermoelectric transport. A considerably increased thermoelectric power factor of 110 μW·m-1·K-2 is achieved for a PSP multilayer film fabricated at 4000 rpm, greatly higher than that of the PEDOT:PSS and solution-mixed SnSeTe/PEDOT:PSS composite film. The multilayer strategy proposed in this study is promising for the fabrication of transparent and hybrid thin-film thermoelectrics with high thermoelectric performances.

Hybrid Gibbsite Nanoplatelet/Cellulose Nanocrystal Multilayered Coatings for Oxygen Barrier Improvement.

We have investigated the ability of multilayered hybrid thin films of cellulose nanocrystals (CNCs) and gibbsite nanoplatelets (GNPs) to be built by the layer-by-layer (LbL) technique onto substrates selected for packaging applications, and to improve the oxygen barrier properties. Using complementary structural characterization techniques, namely atomic force microscopy, ellipsometry, and spectral reflectance, we show that when deposited onto model silicon substrates these hybrid films were homogenous and of reduced porosity, and were comprised of alternately deposited monolayers of GNPs and CNCs. The successful deposition of such homogeneous and dense hybrid thin films onto various types of flexible substrates showing different chemical compositions, hydrophilicity, and surface morphology, ranging from cardboard to smart paper, polyethylene (PE) films, and PE-coated cardboard was also confirmed by scanning electron microscopy observations. In view of the diversity of these substrates we could confirm the remarkable robustness of such a deposition process, likely due to (i) the adaptability of the LbL assembling technique and (ii) the strong electrostatic and hydrogen bonding interactions between GNPs and CNCs. The measurement of the oxygen transmission rate (OTR) at 23°C and 50% RH showed that the oxygen barrier properties of the bare substrates could be significantly improved (e.g., 75% decrease of the OTR) after the deposition of such thin (<100 nm) multilayered hybrid films. This lowered permeability was tentatively attributed to the highly tortuous morphology of the coating, acting to impede the gas diffusion. These partially biosourced very thin films stand as good candidates for using as coatings showing high oxygen barrier performance.

Transition in layer structure of atomic/molecular layer deposited ZnO-zincone multilayers

In this work, atomic-resolution transmission electron microscopy studies show that in atomic/molecular layer deposited ZnO-zincone [(ZnO)a(Zn-O-C6H4-O)b] multilayer thin films, ZnO crystals grow vertically and continuously through lateral zincone monolayers. When the thickness of zincone is increased from one to few monolayers, the growth of the ZnO crystals becomes confined, leading to the formation of discrete ZnO/zincone interfaces accompanied by a decrease in roughness. Apart from providing understanding on the formation of interfaces and on the structure of hybrid multilayers, these findings are relevant, e.g., for understanding thermoelectric interface phenomena at inorganic-organic interfaces and x-ray reflectometry of hybrid multilayer thin films.

On the role of micro-porosity in affecting the environmental stability of atomic/molecular layer deposited (ZnO)a(Zn-O-C6H4-O)b films.

Atomic/molecular layer deposited (ALD/MLD) inorganic-organic thin films form a novel class of materials with tunable properties. In selected cases, hybrid materials are reported to show environmental instability, specifically towards moisture. In this article, we focus on zinc oxide/zincone multi-layers with the theoretical formula of (ZnO)a(Zn-O-C6H4-O)b. We show by means of ellipsometric porosimetry that micro-porosity in the range of 0.42 and 2 nm in the pristine zincone layer is responsible for its environmental degradation. During degradation, it is found that a relative micro-porosity content of 1.2 ± 0.1 vol% in the pristine zincone films evolves into micro-mesoporosity with a relative content of 39 ± 1 vol%. We also show that the micro-porosity in the zincone layer can be gradually suppressed when few cycles (a = 1-10) of ZnO are introduced. The resulting (ZnO)a(Zn-O-C6H4-O)b = 1 periodic multilayer is an environmentally stable film with a = 10. It is found that the suppressed micro-porosity is due to the development of continuous ZnO layers with a≥ 10.

Tunable magnetic properties of the nanoporous hybrid multilayer arrays

Hybrid multilayer films system permits a lot of realization methods of tailoring of the magnetic properties. In this work, nanoporous hybrid multilayer system Ag was fabricated from anodic aluminum oxide (AAO) by a magnetron sputtering methods of room temperature. It is demonstrated that the magnetic properties can be flexibly manipulated by the substrate, noble metal (i.e. silver), the thickness of the ferromagnetic magnetic material (CoFeB) and the indium tin oxide (ITO).

Synthesis of chitosan-based micelles for pH responsive drug release and antibacterial application

The over- and inefficient release of antibiotics from common delivery systems causes the development of drug-resistant bacteria. In the present work, methoxy poly(ethylene glycol)-poly(ε-caprolactone)-chitosan/montmorillonite (MPC/MMT) hybrid multilayer films were constructed for bacterial infections and pH-dependent release of the hydrophobic drug triclosan (TCA). The thickness of the (MPC-T/MMT)10 multilayer films was 384.4 ± 26.5 nm, and the TCA loading dosage was 2.4 μg/cm2. Staphylococcus aureus, Escherichia coli and Staphylococcus epidermidis were used in the antibacterial tests. pH responsive TCA release from the prepared multilayer films was examined by measuring the bactericidal activity of the films after immersion in PBS (pH 7.4) or MES (pH 5.5) and zone of inhibition on nutrient agar. In vitro bacterial shake-flask, zone of inhibition and live/dead staining results demonstrated the high sterilization efficiency of the films. Furthermore, cell biocompatibility measurements toward L929 fibroblasts and human lens epithelial cells showed no adverse effects of the multilayer film.

Construction of High Drug Loading and Enzymatic Degradable Multilayer Films for Self-Defense Drug Release and Long-Term Biofilm Inhibition.

Bacterial infections and biofilm formation on the surface of implants are important issues that greatly affect biomedical applications and even cause device failure. Construction of high drug loading systems on the surface and control of drug release on-demand is an efficient way to lower the development of resistant bacteria and biofilm formation. In the present study, (montmorillonite/hyaluronic acid-gentamicin)10 ((MMT/HA-GS)10) organic/inorganic hybrid multilayer films were alternately self-assembled on substrates. The loading dosage of GS was as high as 0.85 mg/cm2, which could be due the high specific surface area of MMT. The obtained multilayer film with high roughness gradually degraded in hyaluronidase (HAS) solutions or a bacterial infection microenvironment, which caused the responsive release of GS. The release of GS showed dual enzyme and bacterial infection responsiveness, which also indicated good drug retention and on-demand self-defense release properties of the multilayer films. Moreover, the GS release responsiveness to E. coli showed higher sensitivity than that to S. aureus. There was only ∼5 wt % GS release from the film in PBS after 48 h of immersion, and the amount quickly increased to 30 wt % in 105 CFU/mL of E. coli. Importantly, the high drug dosage, smart drug release, and film peeling from the surface contributed to the efficient antibacterial properties and long-term biofilm inhibition functions. Both in vitro and in vivo antibacterial tests indicated efficient sterilization function and good mammalian cell and tissue compatibility.

Facile and Controlled Fabrication of Cu–Al Layered Double Hydroxide Nanosheets/Laccase Hybrid Films: A Route to Efficient Biocatalytic Removal of Congo Red from Aqueous Solutions

The development of biobased hybrid materials that can efficiently remove environmentally contaminants has broad practical applications for areas. In this work, a novel biomaterial–inorganic hybrid film was fabricated with Cu–Al layered double hydroxide (LDH) nanosheets as host and laccase as guest by using exfoliation/self-assembly monolayer technology. It included two processes: first, a nitric acid intercalation Cu–Al–NO3– LDHs was prepared with Cu–Al–CO32– LDHs through the ion-exchange method, and then Cu–Al–NO3– LDHs was exfoliated into a single-layer nanodispersion system with abundant Cu2+ ions on the surface of the positively charged layered double hydroxides to assemble the (LDHs/laccase)n hybrid multilayer film. The resulting (LDHs/laccase)n hybrid film was characterized by X-ray diffraction, scanning electron microscope, high-resolution transmission electron microscopy, scanning probe microscope, and UV–visible absorption spectroscopy, which all supported the formation of the layer-by-layer sand...

Tunable Magneto-Optical Kerr Effects of Nanoporous Thin Films

Magnetoplasmonics, combining magnetic and plasmonic functions, has attracted increasing attention owing to its unique magnetic and optical properties in various nano-architectures. In this work, Ag, CoFeB and ITO layers are fabricated on anodic aluminum oxide (AAO) porous films to form hybrid multi-layered nanoporous thin films by magnetron sputtering deposition process. The designed nanostructure supports localized surface plasmon resonance (LSPR) and tunable magneto-optical (MO) activity, namely, the sign inversion, which can be controlled by AAO porous film geometry (pore diameter and inter-pore spacing) flexibly. The physical mechanism of this special MO phenomena is further analyzed and discussed by the correlation of Kerr rotation and electronic oscillations controlled by the surface plasmon resonance that is related to the nanoporous structure.