Chemical Properties Of Nanomaterials Research Articles

Exploring the relationships between physiochemical properties of nanoparticles and cell damage to combat cancer growth using simple periodic table-based descriptors.

A comprehensive knowledge of the physical and chemical properties of nanomaterials (NMs) is necessary to design them effectively for regulated use. Although NMs are utilized in therapeutics, their cytotoxicity has attracted great attention. Nanoscale quantitative structure-property relationship (nano-QSPR) models can help in understanding the relationship between NMs and the biological environment and provide new ways for modeling the structural properties and bio-toxic effects of NMs. The goal of the study is to construct fully validated property-based models to extract relevant features for estimating and influencing the zeta potential and obtaining the toxicity profile regarding cell damage in the treatment of cancer cells. To achieve this, QSPR modeling was first performed with 18 metal oxide (MeOx) NMs to measure their materials properties using periodic table-based descriptors. The features obtained were later applied for zeta potential calculation (imputation for sparse data) for MeOx NMs that lack such information. To further clarify the influence of the zeta potential on cell damage, a QSPR model was developed with 132 MeOx NMs to understand the possible mechanisms of cell damage. The results showed that zeta potential, along with seven other descriptors, had the potential to influence oxidative damage through free radical accumulation, which could lead to changes in the survival rate of cancerous cells. The developed QSPR and quantitative structure-activity relationship models also give hints regarding safer design and toxicity assessment of MeOx NMs.

Nanomaterial for Adjuvants Vaccine: Practical Applications and Prospects

Vaccines contain adjuvants to strengthen the immune responses of the receiver against pathogen infection or malignancy. A new generation of adjuvants is being developed to give more robust antigen-specific responses, specific types of immune responses, and a high margin of safety. By changing the physical and chemical properties of nanomaterials, it is possible to make antigen-delivery systems with high bioavailability, controlled and sustained release patterns, and the ability to target and image. Nanomaterials can modulate the immune system so that cellular and humoral immune responses more closely resemble those desired. The use of nanoparticles as adjuvants is believed to significantly improve the immunological outcomes of vaccination because of the combination of their immunomodulatory and delivery effects. In this review, we discuss the recent developments in new adjuvants using nanomaterials. Based on three main vaccines, the subunit, DNA, and RNA vaccines, the possible ways that nanomaterials change the immune responses caused by vaccines, such as a charge on the surface or a change to the surface, and how they affect the immunological results have been studied. This study aims to provide succinct information on the use of nanomaterials for COVID-19 vaccines and possible new applications.

Tailoring Vacancy Defects in Isolated Atomically Precise Silver Clusters through Mercury-Doped Intermediates.

Vacancy defects are known to have significant effects on the physical and chemical properties of nanomaterials. However, the formation and structural dynamics of vacancy defects in atomically precise coinage metal clusters have hardly been explored due to the challenges associated with isolation of such defected clusters. Herein, we isolate [Ag28(BDT)12]2- (BDT is 1,3-benzenedithiol), a cluster with a "missing atom" site compared to [Ag29(BDT)12]3-, whose precise structure is known from X-ray diffraction. [Ag28(BDT)12]2- was formed in the gas-phase by collisional heating of [Ag28Hg(BDT)12]2-, a Hg-doped analogue of the parent cluster. The structural changes resulting from the loss of the Hg heteroatom were investigated by trapped ion mobility mass spectrometry. Density functional theory calculations were performed to provide further insights into the defect structures, and molecular dynamics simulations revealed defect site-dependent structural relaxation processes.

Direct quantification of hydrophobicity: a case study of environmentally relevant silver nanoparticles

Among the physical and chemical properties of nanomaterials, hydrophobicity is considered to play a key role in their impact on the environment. Changes in hydrophobicity resulting from abiotic and biotic processes can be used to predict the behaviours of nanoparticles (NPs) in the environment (e.g., aggregation, toxicity, and bioaccumulation). Hydrophobicity changes induced by sulfidation and natural organic matter (NOM) corona formation were evaluated by monitoring the binding rate of silver (Ag) NPs on engineered surfaces using dark-field microscopy (DFM). It was found that this DFM-based method was more capable of distinguishing the hydrophobicity of environmentally relevant AgNPs than the dye adsorption method. Under the conditions tested in this study, sulfidation and adsorption of sulfidized NOM/“lipid-free” (LF-)NOM increased the hydrophobicity of AgNPs. Both methods demonstrate the tendency of AgNPs to become more hydrophobic after sulfidation. This study shows that DFM-based methods can effectively measure the hydrophobicity of environmentally relevant NPs and have the potential to be widely used as fate predictors in the future.

Confinement engineering to enhance broadband microwave absorption of hierarchically magnetic carbon tubular composite

The development of carbon materials remains challenging due to a single loss mechanism and an electromagnetic impedance mismatch. Confinement engineering has been shown to provide a chemical microenvironment for the formation of confined object materials in order to regulate the physical and chemical properties of nanomaterials. In this study, we choose lightweight one-dimensional biomass carbon microtubes as the base, for the first time cleverly using the transition metal nickel only on the inner surface of carbon microtubes with an ultra-small CNT array, and construct a composite with a hierarchically magnetic carbon tubular structure (HMCT-I) on the basis of the theoretical analysis of electromagnetic parameters. Thanks to enhanced magnetic loss and the synergy of multiple polarization losses, HMCT-I ultimately shows encouraging microwave-absorption performance, with an ultra-wide effective absorption bandwidth of 8.44 GHz and an ultra-low reflection loss of −77.7 dB. In addition, the reasonable design makes HMCT-I have superior environmental stability, broadening the way for developing practical broadband carbon-based composite absorbers. This work also provides theoretical guidance and innovative ideas for the design of broadband and efficient microwave absorbers.

Research progress of nanomaterial drug delivery in tumor targeted therapy.

Cancer is one of the most lethal diseases in human society, and its incidence is gradually increasing. However, the current tumor treatment often meets the problem of poor efficacy and big side effects. The unique physical and chemical properties of nanomaterials can target the delivery of drugs to tumors, which can improve the therapeutic effect while reducing the damage of drugs to normal cells. This makes nanomaterials become a hot topic in the field of biomedicine. This review summarizes the recent progress of nanomaterials in tumor targeted therapy.

Ni Doping in MnO2/MXene (Ti3C2Tx) Composites to Modulate the Oxygen Vacancies for Boosting Microwave Absorption

Endowing composites with defects such as oxygen vacancies is an easy and effective strategy to determine the physical and chemical properties of nanomaterials. The influence of defects on microwave absorption remains a very open question. Herein, MnO2/Ti3C2Tx MXene composites are self-assembled, demonstrating the boosting of microwave absorption through Ni doping in MnO2 to modulate the oxygen vacancies. The Ni-doped MnO2 (Ni–MnO2) nanorods with diameters of about 40 nm are dispersed on the surface and interlay of MXene. As expected, the reflection loss (RL) value and effective absorption bandwidth (EAB) of Ni–MnO2/MXene composites are −55.9 dB and 6.32 GHz, which are greatly enhanced over pure MnO2/MXene with −18.8 dB and 4.56 GHz. This excellent microwave absorption is mainly attributed to the optimized impedance matching in Ni–MnO2/MXene composites. In addition, the random distribution of MnO2 nanorods and MXene layers will form a conductive network, leading to the inducing microcurrent to form conduction losses. Moreover, interfacial polarization between layered MXene and Ni–MnO2 and dipole polarization induced by oxygen defects yield a strongly dielectric loss. Thus, our work provides a novel principle of modulation in oxygen vacancies to develop efficient MXene-based multicomponent composites for electromagnetic wave absorption.

Nanostructure engineering of polymeric carbon nitride with boosted photocatalytic antibacterial activity

Nanostructural engineering can achieve smart modulation of the physical and chemical properties of nanomaterials by changing their dimensions, morphologies, and shapes. Nanostructures of different dimensions affect the bactericidal activity of nano‐antibacterial materials. Herein, the nanostructures of the metal‐free antibacterial substance polymeric carbon nitride (PCN) were engineered to prepare. The PCN nanotubes, nanosheets, and microspheres exhibited defined dimensional and morphological characteristics from one‐dimensional (1D) to 2D to 3D. Nanostructuring did not change the crystallization and bonding of PCN, but it profoundly impacted the specific surface area, porosity, absorption spectrum, fluorescence spectrum, photoelectric response, and impedance. Unsurprisingly, the photocatalytic activity of PCN nanostructures in killing Escherichia coli appeared dimensional dependence. The low‐dimensional PCN nanostructures including nanosheets and nanotubes had significantly boosted bactericidal activity; the E. coli survival rates on them after 2 h of visible light irradiation were only 10.4 and 15.8%, respectively. The excellence of the activity can be attributed to the comprehensive effect of strong photo‐generated hole oxidation ability, long photo‐generated carrier lifetime, fast carrier migration rate, large surface area, and sharp shape. The implement of nanostructure engineering provided a promising way to enhance the antibacterial activity of PCN photocatalysts.

Ingeniously enhanced ferromagnetism in chemically-reduced 2D Ti3C2TX MXene

Chemical reduction is a facile and cost-effective technique for the modulation of the physical and chemical properties of nanomaterials. Herein, we demonstrate an enhancement of the magnetic behavior of Ti3C2Tx MXene after its chemical reduction via l-ascorbic acid treatment. Small ferromagnetic loops have been observed below 50 K for Ti3C2Tx prepared by hydrofluoric acid (HF) etching of Al layers from Ti3AlC2. Such a ferromagnetic ordering of spins was significantly enhanced via a chemical reduction of Ti3C2Tx with l-ascorbic acid. Ferromagnetic hysteresis loops were observed for reduced Ti3C2Tx (r-Ti3C2Tx) up to 150 K indicating a significant upshift of the paramagnetic to the ferromagnetic transition temperature, pushing towards room temperature. The enhancement of ferromagnetism and upshift of the ferromagnetic transition temperature could be attributed to the localized unpaired electron in Ti-3d orbital of the r-Ti3C2Tx crystal and increase in the number of unsaturated Ti atoms upon l-ascorbic acid treatment. Chemical reduction via l-ascorbic acid treatment shows a promising pathway towards the modulation and enhancement of magnetism in various MXene materials for the development of 2D metallic soft ferromagnets and spintronic devices.

Investigation on the Synthesis and Chemical Properties of Nanomaterials

Nanoscience is assumed to have capability to change the efficiency of the current electronic and electrical devices. So nanotechnology is being developed to achieve the same. Various kinds of nanomaterials are being prepared such that they show tremendous properties at the nanoscale dimensions. Hence, it is worth studying about the synthesis of nanomaterials. The information that we present in this paper corresponds to a basic review on the synthesis and recent work done on nanomaterials. The distinctness of this review is that, the classification and major types of nanomaterials has been reported. The literature was collected through internet, from various available sources. The synthesis methods that have been discussed are sputtering, hydrothermal, microwave assisted, and electrochemical and chemical reduction methods.

Plant leaf disease classification using deep Convolutional neural network with Bayesian learning

In the present situation, the world's population continues to rise rapidly, while the cultivated land suitable for cultivation stays the same. It forces farmers to demonstrate innovative techniques that improve crop yields to sustain the increasing population. Preserving the health of crops is quite critical in this respect. Therefore, early detection of disease in crops seems to be very crucial to monitor disease and increase crop yield. In this paper, a deep Convolutional Neural Network (DCNN) model is proposed using Bayesian learning process for classification of the diseases in plants. Material used for this work consist of 20,639 images taken from plantVillage having 15 distinct classes of healthy and infected leaf images of potato, tomato and pepper bell. The key objective of this research is the introduction of Bayesian process at the top of residual network for efficient feature learning. An investigation was performed for comparison of proposed DCNN with the traditional classifiers in terms of accuracy, precision, recall and F-score and result indicated that the proposed model is an efficient tool for classification of diseases. Further, the prominent physical or chemical properties of nanomaterials have enabled their use as innovative and high-performance diagnostic toolsfor variedplant pathogens and other important disease biomarkers. Taking these as a pre processing step while acquiring the data set and combining it with proposed work enhances the performance. The proposed approach utilizes the features developed by CNN mostly in different hierarchies to use Bayesian framework and obtains the accuracy rate of 98.9% with no sign of overfitting.

Application of nanomaterials in the treatment of rheumatoid arthritis.

Rheumatoid Arthritis (RA) is a chronic autoimmune disease, which mainly causes inflammation of the synovial joints and destruction of cartilage and bone tissue. At present, a variety of clinical drugs have been applied in the treatment of rheumatoid arthritis. With the development of nanotechnology, more and more nano-drugs have been applied in the treatment of rheumatoid arthritis due to the unique physical and chemical properties of nanomaterials. Treatment of RA with nanomaterials can improve bioavailability and selectively target damaged joint tissue. In this review, we summarized the progress of the application of nanomaterials in the treatment of rheumatoid arthritis and also proposed challenges faced by nanomaterials in the treatment of rheumatoid arthritis.

Nanocomposites for Electrochemical Sensors and Their Applications on the Detection of Trace Metals in Environmental Water Samples.

The elevated concentrations of various trace metals beyond existing guideline recommendations in water bodies have promoted research on the development of various electrochemical nanosensors for the trace metals’ early detection. Inspired by the exciting physical and chemical properties of nanomaterials, advanced functional nanocomposites with improved sensitivity, sensitivity and stability, amongst other performance parameters, have been synthesized, characterized, and applied on the detection of various trace metals in water matrices. Nanocomposites have been perceived as a solution to address a critical challenge of distinct nanomaterials that are limited by agglomerations, structure stacking leading to aggregations, low conductivity, and limited porous structure for electrolyte access, amongst others. In the past few years, much effort has been dedicated to the development of various nanocomposites such as; electrochemical nanosensors for the detection of trace metals in water matrices. Herein, the recent progress on the development of nanocomposites classified according to their structure as carbon nanocomposites, metallic nanocomposites, and metal oxide/hydroxide nanocomposites is summarized, alongside their application as electrochemical nanosensors for trace metals detection in water matrices. Some perspectives on the development of smart electrochemical nanosensors are also introduced.

Carbon nanotube–reinforced polymer composite for electromagnetic interference application: A review

Abstract The growth of the application of electronic devices has created a new form of pollution known as noise or radio frequency interference, electromagnetic radiation, or electromagnetic interference (EMI), which results in the malfunction of equipment. A new carbon-based polymer composite has been unlocked through the discovery of polymer composites. Carbon nanotubes (CNTs) have shown potential as reinforcement fillers in polymer to enhance an EMI shielding material owing to their large specific surface area, well-defined 3D networking structure, and unique electronic structure. The main focus of this review is the role of CNT as fillers in intrinsic conducting polymer and conducting polymer composite. The factors that influence EMI shielding performance are also included in this review. The roles of the size; shape; and electronic, mechanical, and chemical properties of nanomaterials in tuning the EMI shielding effectiveness of polymer hybrid are emphasized. The structural design of CNT polymer composite has been reviewed as well. Future research direction has been proposed to overcome the current technological limitations and realize the most advanced EMI shielding materials for future use. The composites have a potential to replace traditional shielding materials owing to their advantageous properties.

Formation mechanism of CdxZn1-xS/PVA nanocomposites by SILAR method

In this study, CdxZn1-xS/PVA nanocomposites have been grown within polyvinyl alcohol (PVA) polymer matrix using the combined sorption of the cations by the successive ionic layer adsorption and reaction (SILAR) method. The effects of the different amount of Cd2+ and Zn2+ ions depending on the × value in CdxZn1-xS, the number of reaction cycles, various cation sources, and the different reaction parameters on the formation mechanism and physical and chemical properties of nanomaterials were studied in this paper. The structural, optical analysis, chemical composition determination, morphology and the distribution of nanoparticles on the surface are characterized and studied using X-ray diffractometer (XRD), ultraviolet–visible (UV–Vis) spectrophotometer, scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDX) and optical microscopy. The particle size of the sample obtained after 5 cycles is larger than the particle size obtained at 2 cycles. The formation speed of nanoparticles is weak at room temperature and the particle size is in the range of 6.63–9.66 nm after 2 cycles and 8.89–22.7 nm after 5 cycles by SEM. The optical microscope results show that the distribution of elements by thickness is non-uniformity. The reason for non-uniformity is that the volume and surface energy are different. The band gap value of nanoparticles decreases as increasing the concentration of Cd2+ ions in CdxZn1-xS nanostructures. The decrease in Eg depends on the growth of the particle size. This type of materials have great applications in photovoltaics, solar cells, and markers.

Plasmon-based optical sensors for high-sensitivity surface deformation detection of silver and gold

Surface deformation is a common phenomenon in many situations, and can be caused by stress, temperature variation, environmental variation, etc. With the developing of nanotechnology, biological and chemical properties of nano materials are generally in association with its surface condition. High-sensitivity methods of sensing super tiny surface deformations become necessary. In this work, a high sensitive surface deformation sensor is proposed by one-dimensional photonic crystal. Results show that Tamm plasmon polaritons are generated in this configuration and the reflection spectrum is dramatically influenced by the surface deformation of the silver and gold films. The variation rate of reflection light intensity reaches 20% when the surface deformation of is 1 nm. And the variation rate reaches 13% per nanometer for gold surfaces. Since the detecting precision of light intensity is greatly high, the theoretical precision of this device can reach picometer magnitude. Meanwhile, this configuration also can realize mapping surface deformation distribution through scanning method. The simulation results reveal the proposed configuration can distinguish 1 nm surface deformation of silver surfaces.

Multi-method assessment of PVP-coated silver nanoparticles and artificial sweat mixtures

Research presented here utilizes silver nanoparticles (AgNPs) as a case study for how the immediate local environment alters the physical and chemical properties of nanomaterials. Dermal exposure is a primary route for exposure to many of the consumer products containing AgNPs. Interactions between AgNPs and human sweat/perspiration are critical for understanding how changes in Ag speciation will impact exposure. Previous studies have examined silver release from AgNP-containing products after exposure to artificial sweat (AS), however there is no basic assessment of how mixtures of AgNPs and AS alter the physical and chemical properties of AgNPs. The current research evaluated changes in size, aggregation, chemical composition, and silver speciation of four different sizes of AgNPs exposed to four different formulations of AS. The AS formulations were from standardized methods with different chemical compositions, ionic strengths, and pH. Samples were collected at four-time intervals for analysis using dynamic light scattering , UV–Vis spectroscopy, and single-particle inductively coupled plasma-mass spectrometry . Each mixture was also prepared for speciation analysis using X-ray absorption spectroscopy and scanning electron microscopy coupled to energy-dispersive X-ray analysis. The equivalent diameter measurements from the three techniques followed the order of DLS > UV–Vis > spICP-MS. Speciation analyses indicate significant changes for the smaller NPs, while the largest (100 nm) NPs had less measurable differences. This study shows the need to fully understand what specific information an analytical technique might provide and to use those techniques properly in tandem to give the fullest answer to a given research question.

Nanotechnology and food safety

Nanotechnology offers very interesting perspectives for the food industry. Due to the benefits offered by the physical and chemical properties of nanomaterials, the use of these materials is increasing in the food industry. There is concern about the safety of nanomaterials, especially because of the limited knowledge about the effects of these materials on human health. A review of nanotechnology and its main applications in the food industry is carried out, including the different types of nanomaterials available, their toxicity, the risk assessments performed and the actual legal situation in Europe. It is concluded that, in order to maintain a high level of food safety and protect the health of consumers and environment, the potential risks of these new materials need to be properly evaluated and managed. Though, the research should be directed to develop risk assessment of the application of nanomaterials in the food industry.

The application of bio-nanotechnology in tumor diagnosis and treatment: a view

Abstract Nanotechnology is a new technology for observing and manipulating atoms and molecules in the range of 0.1–100 nm. The development of nanotechnology provides a new way for biomedicine. Based on the unique physical and chemical properties of nanomaterials, the novel biosensor based on bio-nanotechnology can be used for early diagnosis and therapy of tumors. Nowadays, the application of nanomedicine is mainly focused on the following points: tissue engineering and regenerative medicine, the accurate diagnosis and real-time monitoring of the disease, novel imaging and analysis techniques, and multifunctional drug delivery system and targeting therapy. Nanotechnology will provide effective means for accurate diagnosis and treatment of cancer. This article reviews the new progress of nanotechnology in cancer diagnosis and treatment.

Advancements in Applications of Surface Modified Nanomaterials for Cancer Theranostics.

Nanostructured material is a solid substance with at least one face is in the range of 1-100 nm. Manipulations in the characteristics and effects of nanostructures can invent new procedures and technologies, as the physical and chemical properties of nanomaterials are noticeably dissimilar from those of a single atom or its bulk phase. This difference in the properties is due to different spatial arrangements and shapes, changes in phase, energetics, electronic structure, chemical reactivity, and catalytic properties of huge, finite systems, and their assemblages. Theranostic involves the study of compounds which associates the modalities of curative and investigative purposes. The aim of this review was to highlight the possible uses of nanoparticles as therapeutic and diagnostic agents. As is evident by the latest applications of nanoparticles in the development of sensitive biosensors as well as in MRI and drug delivery systems. The most important theranostic application of nanoparticles involves the treatment of cancer. In most of the cases, the late diagnosis of the disease is responsible for increasing the mortality rate. Moreover, the toxic effect of the chemotherapeutic drugs on the normal cells of the body seems to be another major drawback of the treatment. Therefore, theranostics appears to be very helpful and realistic area in the diagnosis and targeted drug delivery of this particular disease. We systematically searched for research literature using well-framed review questions and presented data in both the text as well as tabular forms for readers' convenience. The present review collected the data from the published reviews as well as original research papers. The manuscripts considered in this article were taken from the databases and search engines comprising NCBI, PubMed, Google scholar, directory of open access journals, ScienceDirect and local library searches. The properties of the selected articles were analyzed, and a rational quantitative and qualitative content were used for the outcome and inference of the study applying a conceptual foundation. Two hundred seventeen papers were included in the review. Most of the papers were from developed countries (163) and the rest from developing countries (54). Seventy four articles dealt with both the diagnostic as well as therapeutic study of nanomaterials, fifty seven manuscripts included only therapeutic approach and twenty seven papers included only diagnostic approach. The rest of the articles included the data on the synthesis and characterization of surface modified nanomaterials which could be applied in this area. Forty five papers dealt with both in vitro and in vitro studies, sixteen manuscripts involved studies on clinical trials, fifty nine articles gave data on the basis of in vitro experiments and twenty seven articles on the basis of in vivo studies only while 2 papers included in situ data. In the manuscripts considered for the review, the data on both the solid tumors as well as cancers were taken. Almost all types of cancers are being studied using nanomaterials but the most studied cancer for therapeutic and diagnostic approach on the basis of literature is breast cancer. By the help of surface modification of the nanomaterials specific targeting properties towards specific molecules and receptors in various types of cells could be achieved. It has been suggested that the delivered drugs require low amount to achieve the synergy between both the drugs delivered to cancer cells and tissues. Moreover, the toxic effect of the chemotherapeutic drugs on the normal cells of the body is another major drawback of the treatment. Upon further improvement and optimization of these nanoparticle-based strategies, it will ultimately lead to the prediction of patient's response towards a specific molecular therapy and it will be helpful to observe their responses to personalized therapy. Therefore, theranostics appears to be very helpful and realistic area in the diagnosis and targeted drug delivery of this particular disease.