Multifunctional Nanostructured Materials Research Articles

Molecular conformation of polyelectrolytes inside Layer-by-Layer assembled films

Among all methods available for the preparation of multifunctional nanostructured composite materials with remarkable functional properties, Layer-by-Layer (LbL) assembly is currently one of the most widely used techniques due to its environmental friendliness, its ease of use and its versatility in combining a plethora of available colloids and macromolecules into finely tuned multicomponent architectures with nanometer scale control. Despite the importance of these systems in emerging technologies, their nanoscopic 3D structure, and thus the ability to predict and understand the device performance, is still largely unknown. In this article, we use neutron scattering to determine the average conformation of individual deuterated polyelectrolyte chains inside LbL assembled films. In particular, we determine that in LbL-films composed of poly(sodium 4-styrenesulfonate) (PSS) and poly(allylamine hydrochloride) (PAH) multilayers prepared from 2 M sodium chloride solutions the PSS chains exhibit a flattened coil conformation with an asymmetry factor of around seven. Albeit this highly non-equilibrium state of the polymer chain, its density profiles follow Gaussian distributions occupying roughly the same volume as in the bulk complex.

Self-Cleaning Bending Sensors Based on Semitransparent ZnO Nanostructured Films.

The design of multifunctional nanostructured materials is the key to the development of smart wearable devices. For instance, nanostructures endowed with both piezoelectric and photocatalytic activities could well be the workhorse for solar-light-driven self-cleaning wearable sensors. In this work, a simple strategy for the assembly of a flexible, semitransparent piezophotocatalytic system is demonstrated by leveraging rational wet chemistry synthesis of ZnO-based nanosheets/nanoflowers (NSs/NFs) under basic pH conditions onto flexible ITO/PET supports. A KMnO4 pretreatment before the ZnO synthesis (seeded ZnO) allows for the control of the density, size, and orientation of the NSs/NFs systems compared to the systems produced in the absence of seeding (seedless ZnO). The electrical response of the sensors is extracted at a 1 V bias as a function of bending in the interval between 0 and 90°, being the responsivity toward bending significantly enhanced by the KMnO4 treatment effect. The photocatalytic activity of the sensors is analyzed in aqueous solution (methylene blue, 25 μM) by a solar simulator, resulting in similar values between seedless and seeded ZnO. Upon bending the sensor, the photocatalytic activity of seedless ZnO is almost unaffected, whereas that of seeded ZnO is improved by about 25%. The sensor's reusability and repeatability are tested in up to three different cycles. These results open up the way toward the seamless integration of bending sensitivity and photocatalysis into a single device.

One-step architecture of bifunctional petal-like oxygen-deficient NiAl-LDHs nanosheets for high-performance hybrid supercapacitors and urea oxidation

Nickel-based layered double hydroxides (LDHs) are promising electrode materials in the fields of energy storage (supercapacitors) and conversion (urea oxidation). The rational construction of atomic and electronic structure is crucial for nickel-based LDHs to realize their satisfactory electrochemical performance. Herein, we report a facile, ecofriendly, one-step synthesis process to construct petal-like oxygen-deficient NiAl-LDH nanosheets for hybrid super-capacitors (HSCs) and urea oxidation reaction (UOR). The asprepared NiAl−LDH nanosheets with rich oxygen vacancies possess a large specific surface area of 216.6 m2 g−1 and a desirable electronic conductivity of 3.45 × 10−4 S cm−1 to deliver an ultra-high specific capacitance of 2801 F g−1 (700 C g−1) at 1 A g−1. Furthermore, high specific energy of 50.0 W h kg−1 at 400 W kg−1 and excellent cycle stability with 91% capacitance retention after 10,000 cycles are achieved by the NiAl-LDHs/CFP (carbon fiber paper) (+)//YP-80F (a commercial activated carbon) (−) HSC. Besides, NiAl−LDH nanosheets also work as an efficient electrocatalyst for UOR, which only requires 1.42 V vs. reversible hydrogen electrode to drive 10 mA cm−2 in 1 mol L−1 KOH with 0.33 mol L−1 urea. This remarkable performance is superior to most reported values of previous candidates owing to the thin structure of NiAl−LDH nanosheets for exposing more active sites and abundant oxygen vacancies. In addition, various reaction parameters are investigated to optimize the electrochemical performance. In general, this work paves a new way for the architecture of multifunctional nanostructured energy materials.

Advanced Development of Sustainable PECVD Semitransparent Photovoltaics: A Review

Energy is the driving force behind the upcoming industrial revolution, characterized by connected devices and objects that will be perpetually supplied with energy. Moreover, the global massive energy consumption increase requires appropriate measures, such as the development of novel and improved renewable energy technologies for connecting remote areas to the grid. Considering the current prominent market share of unsustainable energy generation sources, inexhaustible and clean solar energy resources offer tremendous opportunities that, if optimally exploited, might considerably help to lessen the ever-growing pressure experienced on the grid nowadays. The R&D drive to develop and produce socio-economically viable solar cell technologies is currently realigning itself to manufacture advanced thin films deposition techniques for Photovoltaic solar cells. Typically, the quest for the wide space needed to deploy PV systems has driven scientists to design multifunctional nanostructured materials for semitransparent solar cells (STSCs) technologies that can fit in available household environmental and architectural spaces. Specifically, Plasma Enhanced Chemical Vapor Deposition (PECVD) technique demonstrated the ability to produce highly transparent coatings with the desired charge carrier mobility. The aim of the present article is to review the latest semi-transparent PV technologies that were impactful during the past decade with special emphasis on PECVD-related technologies. We finally draw some key recommendations for further technological improvements and sustainability.

Nanodiagnosis and nanotreatment of colorectal cancer: an overview

The most suitable strategy to improving the long-term viability of cancer patients and overcoming the high morbidity and severity of cancer is the precise identification of particular tumor markers related to cancer using non-invasive techniques. A suitable and immediate therapeutic action may result in the measurement of biomarkers at various phases of cancer. In this scope, the detection of biomarkers by various nanosensors is at the forefront of innovation into cancer diagnosis due to their specific features such as flexibility, rapid response, precise measurement, and multipathing and miniaturization processability. In this review, different nanobiosensors and several biomarkers were discussed for diagnosis of colorectal cancer. In the last few years, multifunctional nanostructured materials have shown a considerable potential to augment the efficacy, selectivity, specificity, and controlled release of various drugs for colorectal cancer treatment. Nanotechnology-based drug delivery systems hold enormous perspective to minimize systemic toxicity by the construction of modified nanomaterials for target-specific treatment. This review shed light on the current progress of various kinds of nanomaterials such as dendrimers, liposomes, micelles, lipid nanodiscs, nano-cubosomes, and nanoparticles for efficient drug delivery in the treatment of colorectal cancer.

Reaction induced multifunctional TiO2 rod/particle nanostructured materials for screen printed dye sensitized solar cells

This study investigates the potential of utilizing multifunctional nanostructured materials for the efficient light trapping and electron transport in solar cells by combining titanium dioxide (TiO2) rods and nanoparticles. A simple solvothermal method was adopted for the synthesis of coupled morphology adopting the desired precursor with the constant concentration and temperature. The reaction duration (12, 24, 36 and 48 h) was varied and the materials resultant physical, optical and structural characteristics were elucidated to determine the nature of the prepared material. The crystallographic phase of the synthesized samples was determined with XRD and Raman analysis. From the experimental data it is hypothesized that the surface plane of anatase (105) is involved in the deformation of the structure and the formation of the rutile phase. To further investigate on the formation of mixed phase in the prepared sample a computation study was performed using density functional theory coupled to the Hubbard U correction (DFT + U) as a function of volume in both the anatase and rutile phases. The relative stability of the O–Ti–O networks is explored starting from ultrathin materials for four different sizes, of anatase and rutile nanorods separately. Finally, the synthesized TiO2 materials were used to prepare screen printed dye sensitized solar cell (DSSC) devices and their respective properties were quantified.

Mechanical characterization of polyethylene-based thermoplastic composite materials for radiation shielding

Abstract Polyethylene is a hydrogen-rich polymer and has been used in making composite materials for radiation shielding. It has been shown that the radiation shielding properties of polyethylene are enhanced through the incorporation of multifunctional nanostructured materials into the matrix of the polymer. In this study, composites of boron nitride added to injection-molding grade high-density polyethylene (HDPE) were prepared and physically tested for their radiation shielding capabilities. Also, the mechanical properties of these composites were also investigated using the novel technique of AFM indentation. The goal is to create a composite material which exhibits advantageous properties in areas besides radiation shielding, i.e., structural or mechanical properties, which does not inhibit the shielding properties to provide multifunctionality which pure polyethylene materials lack.

An affordable photocatalyst for pharmaceuticals and superior electrocatalyst for methanol oxidation – A dual role by CuWO4 anchored bentonite clay

In this present study, we developed a novel bentonite loaded CuWO4 nanoparticles (BEN-CuWO4 NPs) through the simple hydrothermal method. The as-prepared BEN-CuWO4 NPs was systematically characterized by various spectroscopic techniques including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, Field emission scanning electron microscopy (FESEM), High resolution transmission electron microscopy (HR-TEM), DRS-UV visible spectroscopy, Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS) and Photoluminescence (PL) techniques. For the first time, the BEN-CuWO4 NPs were utilized as a bifunctional catalyst for the photodegradation of Diclofenac sodium (DFS) and electrooxidation of methanol. More distinctively, the BEN-CuWO4 NPs exhibited excellent photocatalytic activity could degrades above 94% DFS solution under visible light illumination with superior stability. Further, BEN-CuWO4 NPs portrayed superior electrocatalytic activity for the oxidation of methanol when compared to the pristine CuWO4. In addition, Impedance studies revealed that the BEN-CuWO4 NPs holds the tremendous dielectrical properties. This present investigation opens a new door way for the synthesis of multifunctional nanostructured materials for practical energy and environmental applications.

Crack Growth Monitoring of CFRP Composites Loaded in Different Environmental Conditions Using Acoustic Emission Method

New materials developed for aerospace structures continuously improve aircraft safety. New multifunctional nanostructured materials with exceptional properties must be tested and validated to exploit their full potential. Delamination is a typical damage mode for laminated composites. Therefore, reliable information regarding crack growth behaviour is needed for all operational environments of an aircraft operated at room temperature, as well as at cryogenic and elevated temperatures. In this paper, crack growth monitoring in a climatic chamber on double-cantilever beam (DCB) specimens using optical devices and acoustic emission (AE) techniques are described. A relationship between cumulative AE energy and crack growth in a plain-weave carbon fibre–reinforced epoxy is investigated under constant displacement rate loading at +80°C and -55°C. Test results are evaluated for specimens with nanofillers in the microstructure and for a reference material. The mechanical properties during delamination are represented by fracture toughness GIC, and they are also correlated with the AE data. The elevated test temperature caused a decreased rate of released AE energy. The results are affected by both temperature and material.

Silicate-based multifunctional nanostructured materials with magnetite and Prussian blue: application to cesium uptake

Multifunctional nanostructured materials with superparamagnetic and adsorbent properties towards cesium ions were developed by a simple procedure consisting of the one-pot synthesis of magnetite and Prussian blue nanoparticles (NPs) in the presence of a porous inorganic solid that acts as a support or nanoplatform simultaneously assembling both types of NPs. Sepiolite, a hydrated magnesium silicate with fibrous morphology, microporosity, large specific surface area and bearing hydroxyl groups in its external surface, was here chosen as the nanoplatform supporting the in situ synthesized NPs, although this methodology was also successfully proved using other inorganic solids like silica gel. The efficacy of the resulting materials in the adsorption of cesium ions from aqueous media, even in the presence of a high concentration of sodium chloride, would allow their application in the removal of radioactive cesium-137 with the advantage of an easy and quick recovery of the pollutant-loaded adsorbents by means of a magnet.

Multimodal microscopy using ‘half and half’ contact mode and ultrasonic force microscopy

Advances in the design and fabrication of multifunctional nanostructured materials require characterization techniques capable of simultaneously mapping multiple material properties with nanoscale resolution. We show that this can be achieved by combining nanomechanical information from ultrasonic force microscopy (UFM) with simultaneously acquired friction force and conductivity measurements from contact mode scanning. This utilizes a ‘half and half’ approach, where the AFM is operated alternatively in UFM and contact mode, with the switching rate sufficiently fast that simultaneous contact mode and UFM information is acquired at each pixel of an image. We demonstrate the potential of such a multimodal approach through its application to composite systems consisting of graphene islands on a copper surface, single-walled carbon nanotubes (SWNTs) on a silicon oxide substrate, and a graphene epoxy composite. The half and half approach enables the friction force to be measured without topographical cross-talk. Application to the SWNT sample reveals a further advantage; due to the superlubricity of UFM it enables standard contact mode imaging techniques to be applied to delicate samples.

Multifunctional nanostructured materials for multimodal cancer imaging and therapy.

This paper reviews the recent research and development of multifunctional nanostructured materials for multimodal imaging and therapy. The biomedical applications for multifunctional imaging, diagnosis and therapy are discussed for several nanostructured materials such as polymeric nanoparticles, magnetic nanoparticles, gold nanomaterials, carbon materials, quantum dots and silica nanoparticles. Due to the unique features of nanostructured materials including the large surface area, structural diversity, multifunctionality, and long circulation time in blood, these materials have emerged as attractive preferences for optimized therapy. Multimodal imaging can be introduced to nanostructured materials for precise and fast diagnosis of cancer, which overcomes the shortcoming of single-imaging modality. Meanwhile, nanostructured materials can be also used to deliver therapeutic agents to the disease site in order to accomplish multimodal imaging and simultaneous diagnosis and therapy.

Visible light-triggered nitric oxide release from near-infrared fluorescent nanospheric vehicles.

Bifunctional Ag2S QDs@CS-RBS nanospheres with ultralow toxicity for biomedical use were fabricated. These are capable of releasing NO under irradiation of visible light and emitting in near-infrared (NIR) region fluorescence excited by NIR laser under physiological environment. Glutathiose (GSH)-capped Ag2S QDs were synthesized and encapsulated by chitosan (CS) to form NIR fluorescent Ag2S QDs@CS nanospheres. A type of iron/sulfur/-nitrosyl cluster, Roussin's black salt anion Fe4S3(NO)7(-) (RBS) was conjugated with the Ag2S QDs@CS to obtain Ag2S QDs@CS-RBS nanospheres. A variety of characterization methods were employed to analyze the nanospheres. In vitro cell imaging and in vivo mice imaging experiments demonstrated that the Ag2S QDs@CS-RBS nanospheres could emit readily observable NIR fluorescence and deliver NO in living cells and small animals. The NIR imaging of the Ag2S QDs@CS nanospheres would not interfere with the light-triggered NO release from them, as the excitation lasers needed for these two functions are in different wavelength regions. This work provides new perspectives for the application of multifunctional nano-structured materials in diagnostics and bioimaging.

Ag2S Quantum Dots Conjugated Chitosan Nanospheres toward Light-Triggered Nitric Oxide Release and Near-Infrared Fluorescence Imaging

Nanoscaled light-triggered nitric oxide (NO) delivery vehicles with the ability of near-infrared (NIR) fluorescence imaging was presented, which consisted of chitosan (CS)-based S-nitrosothiols (SNO) and encapsulated silver sulfide quantum dots (Ag2S QDs). CS-SNO compounds that bore NO-storing functional groups were prepared via amino modification of chitosan. Water-soluble Ag2S QDs were synthesized and conjugated with the CS-SNO compounds with the aid of ethylenediaminetetraacetic acid (EDTA). The biocompatible Ag2S-CS-SNO nanospheres, with dimension of ∼117 nm, exhibited bright NIR fluorescence and satisfactory photostability under NIR irradiation. The Ag2S-CS-SNO nanospheres could release NO under irradiation of UV or visible light at physiological pH and temperature yet would hardly release NO if NIR irradiation was applied. Cell imaging was successfully performed, demonstrating that the Ag2S-CS-SNO nanospheres could emit readily observable NIR fluorescence and release NO in living cells. The NIR fluorescence imaging of the Ag2S-CS-SNO nanospheres did not interfere with the light-triggered NO release from them, which would provide new perspectives for the application of multifunctional nanostructured materials in diagnostics and imaging.

Conjugating S-Nitrosothiols with Glutathiose Stabilized Silver Sulfide Quantum Dots for Controlled Nitric Oxide Release and Near-Infrared Fluorescence Imaging

Light-controllable nitric oxide (NO) delivery nanoparticles with the capability of near-infrared (NIR) fluorescence imaging were reported. Water-dispersible Ag2S quantum dots (QDs) were synthesized via a one-pot procedure using reduced glutathiose (GSH) as both sulfur source and stabilizer. S-nitrosothiols (RSNOs) were conjugated with the GSH stabilized Ag2S QDs at the amino groups of the GSH, leading to Ag2S-GSH-SNO nanoparticles with dimension of ~5.5 nm. The biocompatible Ag2S-GSH-SNO nanoparticles could release NO under UV or visible irradiation and emit NIR fluorescence under NIR excitation for bioimaging at physiological pH and temperature, yet could hardly release NO when NIR irradiation was applied. In vitro cell imaging and mice imaging experiments demonstrated that the Ag2S-GSH-SNO nanoparticles could emit readily observable NIR fluorescence and release NO in living cells and small animals. The NIR fluorescence imaging of the Ag2S-GSH-SNO nanoparticles would not interfere with the light-triggered NO release from them, as the excitation lights needed for these two functions were in different wavelength regions. This work provides new perspectives for the application of multifunctional nanostructured materials in diagnostics and imaging.

ChemInform Abstract: Hybrid Nanostructures for Energy Storage Applications

AbstractReview: 208 refs.

Hybrid Nanostructures for Energy Storage Applications

Materials engineering plays a key role in the field of energy storage. In particular, engineering materials at the nanoscale offers unique properties resulting in high performance electrodes and electrolytes in various energy storage devices. Consequently, considerable efforts have been made in recent years to fulfill the future requirements of electrochemical energy storage using these advanced materials. Various multi-functional hybrid nanostructured materials are currently being studied to improve energy and power densities of next generation storage devices. This review describes some of the recent progress in the synthesis of different types of hybrid nanostructures using template assisted and non-template based methods. The potential applications and recent research efforts to utilize these hybrid nanostructures to enhance the electrochemical energy storage properties of Li-ion battery and supercapacitor are discussed. This review also briefly outlines some of the recent progress and new approaches being explored in the techniques of fabrication of 3D battery structures using hybrid nanoarchitectures.

Hydrophobic, Antireflective, Self-Cleaning, and Antifogging Sol−Gel Coatings: An Example of Multifunctional Nanostructured Materials for Photovoltaic Cells

Antireflective, photocatalytic (self-cleaning), water repellent, and high water-wetting (anti fogging) properties were combined for the first time into a sol−gel coating deposited onto glass substrates. Such an original multifunctional coating was obtained by sol−gel liquid deposition of two successive oxide layers. The first coating is composed of a hybrid methyl-functionalized nanoporous SiO2 material that exhibits high transparency, high water resistance, close to null water adsorption, and fairly high mechanical stability (transversal Young Modulus: 1.5 GPa). Thickness and refractive index can be controlled by selecting proper chemical and processing conditions so as to adjust the antireflectivity properties. The second layer is an ultrathin crystalline TiO2 nanoperforated layer that was deposited on top of the previous antireflective layer. Its thickness and refractive index were adjusted around 12 nm and n ≈ 1.8 respectively. This hard TiO2 top layer acts as a protecting barrier toward mechanical ag...

ChemInform Abstract: Multifunctional Nanostructured Materials for Multimodal Imaging, and Simultaneous Imaging and Therapy

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Multifunctional nanostructured materials for multimodal imaging, and simultaneous imaging and therapy

Nanotechnology offers tremendous potential for future biomedical technology. Due to their unique characteristics including superparamagnetic or fluorescent properties, and small size comparable to biomolecules, nanostructured materials have emerged as novel bioimaging, diagnostic, and therapeutic agents for the future medical field. Especially, the combinations of various nanostructured materials with different properties can offer synergetic multifunctional nanomedical platforms, which make it possible to accomplish multimodal imaging, and simultaneous diagnosis and therapy. Moreover, the conjugation of targeting moieties on the surface of these multifunctional nanomaterials gives them specific targeted imaging and therapeutic properties. In this tutorial review, we will summarize the recent reports on the fabrication strategies of multifunctional nanoplatforms and their applications to targeted multimodal imaging and simultaneous diagnosis and therapy.