Chemistry Of Nanomaterials Research Articles

Structure Distortion Endows Copper Nanoclusters with Surface-Active Uncoordinated Sites for Boosting Catalysis.

The utilization of structure distortion to modulate the electronic structure and alter catalytic properties of metallic nanomaterials is a well-established practice, but accurately identifying and comprehensively understanding these distortions present significant challenges. Ligand-stabilized metal nanoclusters with well-defined structures serve as exemplary model systems to illustrate the structure chemistry of nanomaterials, among which few studies have investigated nanocluster models that incorporate structural distortions. In this work, a novel copper hydride nanocluster, Cu42(PPh3)8(RS)4(CF3COO)10(CH3O)4H10 (Cu42; PPh3 is triphenylphosphine and RSH is 2,4-dichlorophenylthiol), with a highly twisted structure has been synthesized in a simple way. Structural analysis reveals Cu42 comprises two Cu25 units that are conjoined in a nearly orthogonal manner. The dramatic distortion in the metal framework, which is driven by multiple interactions from the surface ligands, endows the cluster with a rich array of uncoordinated metal sites on the surface. The resulting cluster, as envisioned, exhibits remarkable activity in catalyzing carbonylation of anilines. The findings from this study not only provides atomically precise insights into the structural distortions that are pertinent to nanoparticle catalysts but also underscores the potential of structurally distorted NCs as a burgeoning generation of catalysts with precise structures and outstanding performances that can be tailored for specific functions.

Trachyspermum ammi Mediated Green Synthesis of NiO Nanoparticles: Dual Role in Photocatalytic Degradation and Anti-bacterial Efficacy

ABSTRACT Nowadays, there is a lot of discussion in science about green chemistry of nanomaterials, from synthesis to various environmental applications. Herein, we describe a simple, environmentally friendly, economically feasible, free of additives, phytosynthetic methodology for the synthesis of cubic phased NiO nanoparticles using the seed extract of Trachyspermum ammi (also known as Ajwain), which acts as a capping and reducing agent that helps in reducing nickel sulphate (NiSO4.6 H2O) to NiO via co-precipitation method. Various spectroscopic techniques were involved in investigating the phase, morphology, functional groups, crystallinity, size, elemental confirmation, optical property with band gap of the green synthesised NiO Nanoparticles. Moreover, green NiO nanoparticles displayed excellent degradation efficiency for the reduction of industrial pollutant, Allura red and possible mechanism were also suggested. Nearly 91.73% of the Allura red was degraded using the synthesised NiO nanoparticles within 90 min when exposed to UV-light. Moreover, the used nanoparticles were renewed and again their photocatalytic performance was assessed for three consecutive cycles. In addition to photocatalytic activity, the green NiO nanoparticles revealed the considerable anti-bacterial activity against Staphylococcus aureus and Escherichia coli and the dead percentage was calculated as 92.56% and 94.33% respectively. In this work, green NiO nanoparticles was involved as a dual functioning agent for effective photocatalytic and anti-bacterial studies.

Synthesis and Characterization of Superparamagnetic Iron Oxide Nanoparticles: A Series of Laboratory Experiments.

The following laboratory procedure provides students with hands-on experience in nanomaterial chemistry and characterization. This three-day protocol is easy to follow for undergraduates with basic chemistry or materials science backgrounds and is suitable for inclusion in upper-division courses in inorganic chemistry or materials science. Students use air-free chemistry procedures to synthesize and separate iron oxide magnetic nanoparticles and subsequently modify the nanoparticle surface by using a chemical stripping agent. The morphology and chemical composition of the nanoparticles are characterized using electron microscopy and dynamic light scattering measurements. Additionally, magnetic characterization of the particles is performed using an inexpensive open-source (3D-printed) magnetophotometer. Possible modifications to the synthesis procedure, including the incorporation of dopants to modify the magnetic response and alternative characterization techniques, are discussed. The three-day synthesis, purification, and characterization laboratory will prepare students with crucial skills for advanced technology industries such as semiconductor manufacturing, nanomedicine, and green chemistry.

The Translation of Nanomedicines in the Contexts of Spinal Cord Injury and Repair.

Manipulating or re-engineering the damaged human spinal cord to achieve neuro-recovery is one of the foremost challenges of modern science. Addressing the restricted permission of neural cells and topographically organised neural tissue for self-renewal and spontaneous regeneration, respectively, is not straightforward, as exemplified by rare instances of translational success. This review assembles an understanding of advances in nanomedicine for spinal cord injury (SCI) and related clinical indications of relevance to attempts to design, engineer, and target nanotechnologies to multiple molecular networks. Recent research provides a new understanding of the health benefits and regulatory landscape of nanomedicines based on a background of advances in mRNA-based nanocarrier vaccines and quantum dot-based optical imaging. In relation to spinal cord pathology, the extant literature details promising advances in nanoneuropharmacology and regenerative medicine that inform the present understanding of the nanoparticle (NP) biocompatibility-neurotoxicity relationship. In this review, the conceptual bases of nanotechnology and nanomaterial chemistry covering organic and inorganic particles of sizes generally less than 100 nm in diameter will be addressed. Regarding the centrally active nanotechnologies selected for this review, attention is paid to NP physico-chemistry, functionalisation, delivery, biocompatibility, biodistribution, toxicology, and key molecular targets and biological effects intrinsic to and beyond the spinal cord parenchyma. The advance of nanotechnologies for the treatment of refractory spinal cord pathologies requires an in-depth understanding of neurobiological and topographical principles and a consideration of additional complexities involving the research's translational and regulatory landscapes.

Conference on Research and Innovations in Science and Technology of Material (CRISTMAS 2023)

École Nationale Supérieure de Chimie de Paris, ParisTech, France13-15 December 2023This collection focuses on the recent innovations in Materials Science and advanced characterisations methods presented at the Conference on research and Innovations in Science and Technology CRISTMAS 2023. It covers topics ranging from advances in the most critical aspects in chemistry and material fabrication of nanomaterials, to the engineering of prototype devices and systems. Editorial Board: • Anna Baldycheva, University of Exeter, UK • Pavel Ginzburg, Tel Aviv University, Israel • Alexander Gumennik, Indiana University, USA • Andrei Gorodetsky, University of Birmingham, UK Scientific and Organising Committee: Anna Baldycheva, University of Exeter, UK Andrei Gorodetsky, University of Birmingham, UK Jèrome Tignon, Sorbonne University & Ècole Normale Superieure, France Pavel Ginzburg, Tel Aviv University, Israel Alexander Gumennik, Indiana University, USA Ben Hogan, Queen’s University, Canada Iveta Steblevska, Queen’s University, Canada Hani Bahrum, Tel Aviv University, Israel

Sustainable Photocatalytic Acylation of Transition Metal Dichalcogenides with Atom Economy.

Transition metal dichalcogenides (TMDs) are promising 2D nanomaterials for diverse applications, but their intrinsic chemical inertness hinders their modification. Herein, a novel approach is presented for the photocatalytic acylation of 2H-MoS2 and 2H-MoSe2, utilizing tetrabutyl ammonium decatungstate ((nBu4N)4W10O32) polyoxometalate complex as a catalyst and a conventional halogen lamp as a source of irradiation. By harnessing the semiconducting properties of TMDs, new avenues emerge for the functionalization of these materials. This novel photocatalytic protocol constitutes the first report on the chemical modification of 2D nanomaterials based on a catalytic protocol and applies to both aliphatic and aromatic substrates. The scope of the decatungstate-photocatalyzed acylation reaction of TMDs is explored by employing an alkyl and an aromatic aldehyde and the success of the methodology is confirmed by diverse spectroscopic, thermal, microscopy imaging, and redox techniques. This catalytic approach on modifying 2D nanomaterials introduces the principles of atom economy in a functionalization protocol for TMDs. It marks a transformative shift toward more sustainable and efficient methodologies in the realm of TMD modification and nanomaterial chemistry.

Nanotechnology-based delivery of therapeutics through the intranasal pathway and the blood-brain barrier for Alzheimer's disease treatment.

Background: drugs for Alzheimer's disease (AD) fail to exhibit efficacy in clinical trials for a number of reasons, a major one being blood-brain barrier (BBB) permeability. Meanwhile, the increasing incidence of this disease emphasizes the need for effective therapeutics. Herein, we discuss novel nanoplatform technologies developed for the effective delivery of AD drugs by traversing the BBB. Main text: the interfacial and surface chemistry of nanomaterials is utilized in several industries, including pharmaceutical, and has drawn considerable attention in the field of nanotechnology. Various reports have suggested the potential of nanotechnology for AD treatment, describing unique drug carriers that improve drug stability and solubility while maintaining therapeutic dosages. These nanotechnologies are harnessed for the transport of drugs across the BBB, with or without surface modifications. We also discuss the transfer of drugs via the nose-to-brain pathway, as intranasal delivery enables direct drug distribution in the brain. In addition, nanomaterial modifications that prolong drug delivery and improve safety following intranasal administration are addressed. Conclusion: although several studies have yielded promising results, limited efforts have been undertaken to translate research findings into clinical contexts. Nevertheless, nanomaterials hold considerable potential for the development of novel effective therapeutic solutions against AD.

Understanding of surface chemistry of silica-based nanomaterials contributes to the design of safe and efficacious nanomedicine

Understanding of surface chemistry of silica-based nanomaterials contributes to the design of safe and efficacious nanomedicine

Biocompatibility of graphene oxide nanosheets functionalized with various amino acids towards mesenchymal stem cells

Graphene and its derivatives have gained popularity due to their numerous applications in various fields, such as biomedicine. Recent reports have revealed the severe toxic effects of these nanomaterials on cells and organs. In general, the chemical composition and surface chemistry of nanomaterials affect their biocompatibility. Therefore, the purpose of the present study was to evaluate the cytotoxicity and genotoxicity of graphene oxide (GO) synthesized by Hummer's method and functionalized by different amino acids such as lysine, methionine, aspartate, and tyrosine. The obtained nanosheets were identified by FT-IR, EDX, RAMAN, FE-SEM, and DLS techniques. In addition, trypan blue and Alamar blue methods were used to assess the cytotoxicity of mesenchymal stem cells extracted from human embryonic umbilical cord Wharton jelly (WJ-MSCs). The annexin V staining procedure was used to determine apoptotic and necrotic death. In addition, COMET and karyotyping techniques were used to assess the extent of DNA and chromosome damage. The results of the cytotoxicity assay showed that amino acid modifications significantly reduced the concentration-dependent cytotoxicity of GO to varying degrees. The GO modified with aspartic acid had the lowest cytotoxicity. There was no evidence of chromosomal damage in the karyotyping method, but in the comet assay, the samples modified with tyrosine and lysine showed the greatest DNA damage and rate of apoptosis. Overall, the aspartic acid-modified GO caused the least cellular and genetic damage to WJ-MSCs, implying its superior biomedical applications such as cell therapy and tissue engineering over GO.

Combining surface-accessible Ag and Au colloidal nanomaterials with SERS for in situ analysis of molecule-metal interactions in complex solution environments.

The interactions between molecules and noble metal nanosurfaces play a central role in many areas of nanotechnology. The surface chemistry of noble metal surfaces under ideal, clean conditions has been extensively studied; however, clean conditions are seldom met in real-world applications. We developed a sensitive and robust characterization technique for probing the surface chemistry of nanomaterials in the complex environments that are directly relevant to their applications. Surface-enhanced Raman spectroscopy (SERS) can be used to probe the interaction of plasmonic nanoparticles with light to enhance the Raman signals of molecules near the surface of nanoparticles. Here, we explain how to couple SERS with surface-accessible plasmonic-enhancing substrates, which are capped with weakly adsorbing capping ligands such as citrate and chloride ions, to allow molecule-metal interactions to be probed in situ and in real time, thus providing information on the surface orientation and the formation and breaking of chemical bonds. The procedure covers the synthesis and characterization of surface-accessible colloids, the preliminary SERS screening with agglomerated colloids, the synthesis and characterization of interfacial nanoparticle assemblies, termed metal liquid-like films, and the in situ biphasic SERS analysis with metal liquid-like films. The applications of the approach are illustrated using two examples: the probing of π-metal interactions and that of target/ligand-particle interactions on hollow bimetallic nanostars. This protocol, from the initial synthesis of the surface-accessible plasmonic nanoparticles to the final in situ biphasic SERS analysis, requires ~14 h and is ideally suited to users with basic knowledge in performing Raman spectroscopy and wet synthesis of metal nanoparticles.

N-Heterocyclic Carbene Boranes: Dual Reagents for the Synthesis of Gold Nanoparticles.

N-heterocyclic carbenes (NHCs) have drawn considerable interest in the field of nano-materials chemistry as highly stabilizing ligands enabling formation of strong and covalent C-metal bonds. Applied to gold nanoparticles synthesis, the most common strategy consists in the reduction of a preformed NHC-Au(I) complex with a large excess of a reducing agent rendering the particle size difficult to control. In this paper, we report on the straightforward synthesis of NHC-coated gold nanoparticles (NHC-AuNPs) by reacting a commercially-available gold(I) precursor with an easy-to-synthesize NHC-BH3reagent. The latter acts as both the reducing agent and the source of surface ligands operating under mild conditions. Mechanistic studies including NMR spectroscopy and mass spectrometry demonstrate that the reduction of gold(I) generates NHC-BH2Cl as a byproduct. This strategy garners efficient control over the nucleation and growth of gold particles by varying the NHC-borane/gold(I) ratio, allowing unparalleled particle size variation in the range of 4.9 ± 0.9 nm to 10.0 ± 2.7 nm. Our strategy also allows the unprecedented precise and controlled seeded growth of gold nanoparticles. In addition, the as-prepared NHC-AuNPs exhibit narrow size distributions without engaging extensive purification or size selectivity techniques and are stable over months.

Facile Scale-Up of the Flow Synthesis of Silver Nanostructures Based on Norrish Type I Photoinitiators.

Silver nanoparticles have become one of the most commercially and industrially relevant nanomaterials of the 21st century, owing to their potent antibacterial properties, as well as their useful catalytic and optical properties. Although many methods have been explored to produce AgNPs, we favor the photochemical approach using photoinitiators to produce AgNPs, owing to the high degree of control over reaction conditions, and the generation of so-called AgNP 'seeds' that can be used as-is, or as precursors for other silver nanostructures. In this work, we explore the scale-up of AgNP synthesis using flow chemistry and assess the usefulness of a range of industrial Norrish Type 1 photoinitiators in terms of flow compatibility and reaction time, as well as the resulting plasmonic absorption and morphologies. We establish that while all the photoinitiators used were able to generate AgNPs in a mixed aqueous/alcohol system, photoinitiators that generate ketyl radicals showed the greatest promise in terms of reaction times, while also showing greater flow compatibility compared to photoinitiators that generate 𝛼-aminoalkyl and α-hydroxybenzyl radicals. These findings help to establish a guideline for adapting photochemical AgNP syntheses to flow systems, helping to improve the scalability of the method in one of the largest industries in nanomaterial chemistry.

Synthesis of two-dimensional van der waals superlattices, heterostructures, and alloys from conversion of sequentially layered sub-nanometer metal films

Manipulation of bulk material properties by controlling layer-by-layer chemistry and structure of nanomaterials has remained an overarching goal of nanoscience and nanoengineering. In the case of two-dimensional (2D) materials, heterostructures consisting of different compositions, stacking, and orientation can serve as a platform for designing bulk material properties; however, fundamental challenges associated with materials processes have limited material quality and impeded scalability. Most attempts to overcome this limitation have relied on slow layer-by-layer growth or meticulous transfer of grown single layers. Our work describes a method to directly convert easily fabricated sub-nanometer metal multilayer heterostructures on both sapphire and SiO2 substrates followed by conversion to 2D van der Waals superlattices, heterostructures, and alloys. These materials exhibit novel bulk properties compared to individual 2D layers themselves including reduced bandgap, enhanced light-matter coupling, and improved catalytic performance. The process versatility enables tunable orientation, layer structure, and chemistry in an exciting class of 2D nanomaterials and provides an opportunity to generate a wide range of artificially stacked multicompositional 2D structures with controlled morphologies.

Biobased Nanomaterials─The Role of Interfacial Interactions for Advanced Materials.

This review presents recent advances regarding biomass-based nanomaterials, focusing on their surface interactions. Plant biomass-based nanoparticles, like nanocellulose and lignin from industry side streams, hold great potential for the development of lightweight, functional, biodegradable, or recyclable material solutions for a sustainable circular bioeconomy. However, to obtain optimal properties of the nanoparticles and materials made thereof, it is crucial to control the interactions both during particle production and in applications. Herein we focus on the current understanding of these interactions. Solvent interactions during particle formation and production, as well as interactions with water, polymers, cells and other components in applications, are addressed. We concentrate on cellulose and lignin nanomaterials and their combination. We demonstrate how the surface chemistry of the nanomaterials affects these interactions and how excellent performance is only achieved when the interactions are controlled. We furthermore introduce suitable methods for probing interactions with nanomaterials, describe their advantages and challenges, and introduce some less commonly used methods and discuss their possible applications to gain a deeper understanding of the interfacial chemistry of biobased nanomaterials. Finally, some gaps in current understanding and interesting emerging research lines are identified.

Nanoscale Surface Structure of Nanometer-Thick Ferroelectric BaTiO3 Films Revealed by Synchrotron X-ray Scanning Tunneling Microscopy: Implications for Catalytic Adsorption Reactions

Ferroelectric nanomaterials are of interest in catalysis, nonvolatile memory, and neuromorphic computing among other applications because of their switchable structure that can alter the electronic and interface properties of a single material. The investigation of the role of polarization on the surface structure and chemistry of ferroelectric nanomaterials is a longstanding challenge, as it ideally requires a combination of both nanoscale imaging and chemical spectroscopy. In this work, we study a model ferroelectric BaTiO3 thin film by synchrotron X-ray scanning tunneling microscopy (SX-STM), a unique method that integrates nanoscale surface imaging and chemically sensitive spectroscopy. We find that polarization switching from downward to upward in (001) single-crystalline BaTiO3 thin films increases the intensity of X-ray absorption across Ba M, Ti L, and O K edges. Chemical mapping of nanometer-sized domains further demonstrates the modulation of surface structures upon polarization switching, as well as confirming the trends observed in single-point experiments across the surface. We complement these measurements with ab initio computational absorption spectroscopy to elucidate the effect of polarization switching on the core–hole excitations using the Bethe–Salpeter equation approach. Our experimental and theoretical results thus confirm a stronger binding strength for the upward-polarized surface with molecular O2 as a model reactant, offering mechanistic evidence that supports previous reports. This work advances the understanding of the surface chemistry and electronic structure of ferroelectrics, which can ultimately aid strategies to design interfaces with tailored properties.

Purification of Water Using Nanotechnology

One of the most crucial ingredients for life on earth is water. It has played a crucial role in the development of human civilizations, starting with the emergence of the first aspect of existence in seawater. The demand for clean water is universal and essential to all human species. But at the moment, pure water supplies are being poisoned. Water quality and society's level of development have recently been linked. The safety of drinking water has been put in jeopardy by several chemical and biological pollutants. Alternatives for decontaminating and reusing water are among the most desired solutions to address the issues of water shortage and the escalating disputes over this essential resource. A significant issue is the buildup of organic debris and its residues in wastewater. Significant progress has been achieved in using the chemistry of nano-materials for purifying water as a result of the realization of the molecular nature of pollution in drinking water. Due to its capacity to produce precise, structurally controlled materials for such needs, nanotechnology offers exceptional potential in filtering applications. By extending the idea of clean, inexpensive, and sustainable water to the ecosystem as a whole, we point out that cities may live and breathe comfortably by using such technology. Sustainability in clean water may be achieved by comprehending the major environmental issues facing the world and investigating potential solutions from new nanotechnologies.

Copper phosphate nanosheets as high-performance oil-based nanoadditives: Tribological properties and lubrication mechanism

Geometric variables and surface chemistry of nanomaterials as lubricant additives both affect the details on the interacting frictional surface. Herein, copper phosphate nanosheets (CPNs) were synthesized by a simple and facile method, which exhibited extraordinary tribological properties as the novel lubricating oil nanoadditives. Compared with the base oil, the friction coefficient (COF) has been reduced by 77% by CPNs at a concentration of 20 wt%, which could also protect the titanium alloy surface from any measurable wear. But as the CPNs content increased to 25 wt%, the shear jamming caused by hydrogen bonding between crystal water in CPNs may interfere with lubrication. Besides, it is significantly effective in preventing the adhesions of titanium alloy on the surface of counterface at a suitable concentration. The extraordinary tribological performance is contributed to the nanosheets of copper phosphate but not the nanoparticles. Moreover, in the presence of CPNs, the tribo-film containing CPNs is formed during sliding contact, but this tribo-film can’t hold for a long time without CPNs, indicating that CPNs can well retain the tribo-film. However, the dominant factor for friction reduction and antiwear is not this tribo-film but the solid-liquid interface lubrication between nanosheets and lubricating oil. The Stribeck curves were used to explain how CPNs play a role in boundary lubrication and mixed lubrication.

Interview: insights from a career developing and applying magnetic nanoparticles.

T Sen is a Reader in Nanomaterials Chemistry at the University of Central Lancashire (UCLan). He trained as a chemist, achieving his BSc Hons in Chemistry, MSc in Physical Chemistry and PhD in Materials Chemistry from the National Chemical Laboratory (Pune, India). Alongside his academic posting, he is an editorial board member for several journals including Nanomedicine. His work at UCLan is multidisciplinary, drawing from chemistry, material science, biology and medicine to work with industry and academic partners to address challenges in health and environmental sciences. The research group currently has three projects: magneto-optical nanocomposites for liver cancer therapeutics; the separation and identification of viral RNAs using magnetic nanoparticles in the context of coronavirus and developing multifunctional nanocomposites for the detection and separation of wastewater toxicity and treatment.

Universal Ligands for Dispersion of Two-Dimensional MXene in Organic Solvents.

Ligands can control the surface chemistry, physicochemical properties, processing, and applications of nanomaterials. MXenes are the fastest growing family of two-dimensional (2D) nanomaterials, showing promise for energy, electronic, and environmental applications. However, complex oxidation states, surface terminal groups, and interaction with the environment have hindered the development of organic ligands suitable for MXenes. Here, we demonstrate a simple, fast, scalable, and universally applicable ligand chemistry for MXenes using alkylated 3,4-dihydroxy-l-phenylalanine (ADOPA). Due to the strong hydrogen-bonding and π-electron interactions between the catechol head and surface terminal groups of MXenes and the presence of a hydrophobic fluorinated alkyl tail compatible with organic solvents, the ADOPA ligands functionalize MXene surfaces under mild reaction conditions without sacrificing their properties. Stable colloidal solutions and highly concentrated liquid crystals of various MXenes, including Ti2CTx, Nb2CTx, V2CTx, Mo2CTx, Ti3C2Tx, Ti3CNTx, Mo2TiC2Tx, Mo2Ti2C3Tx, and Ti4N3Tx, have been produced in various organic solvents. Such products offer excellent electrical conductivity, improved oxidation stability, and excellent processability, enabling applications in flexible electrodes and electromagnetic interference shielding.

High-Throughput Sizing, Counting, and Elemental Analysis of Anisotropic Multimetallic Nanoparticles with Single-Particle Inductively Coupled Plasma Mass Spectrometry.

Nanoparticles (NPs) have wide applications in physical and chemical processes, and their individual properties (e.g., shape, size, and composition) and ensemble properties (e.g., distribution and homogeneity) can significantly affect the performance. However, the extrapolation of information from a single particle to the ensemble remains a challenge due to the lack of suitable techniques. Herein, we report a high-throughput single-particle inductively coupled plasma mass spectrometry (SP-ICP-MS)-based protocol to simultaneously determine the size, count, and elemental makeup of several thousands of (an)isotropic NPs independent of composition, size, shape, and dispersing medium with atomistic precision in a matter of minutes. By introducing highly diluted nebulized aqueous dispersions of NPs directly into the plasma torch of an ICP-MS instrument, individual NPs are atomized and ionized, resulting in ion plumes that can be registered by the mass analyzer. Our proposed protocol includes a phase transfer step for NPs synthesized in organic media, which are otherwise incompatible with ICP-MS instruments, and a modeling tool that extends the measurement of particle morphologies beyond spherical to include cubes, truncated octahedra, and tetrahedra, exemplified by anisotropic Cu NPs. Finally, we demonstrate the versatility of our method by studying the doping of bulk-dilute (<1 at. %) CuAg nanosurface alloys as well as the ease with which ensemble composition distributions of multimetallic NPs (i.e., CuPd and CuPdAg) can be obtained providing different insights in the chemistry of nanomaterials. We believe our combined protocol could deepen the understanding of macroscopic phenomena involving nanoscale structures by bringing about a statistics renaissance in research areas including, among others, materials science, materials chemistry, (nano)physics, (nano)photonics, catalysis, and electrochemistry.