Nanocones Research Articles

Optimizing predictive models for evaluating the F-temperature index in predicting the π-electron energy of polycyclic hydrocarbons, applicable to carbon nanocones

In the fields of mathematics, chemistry, and the physical sciences, graph theory plays a substantial role. Using modern mathematical techniques, quantitative structure-property relationship (QSPR) modeling predicts the physical, synthetic, and natural properties of substances based only on their chemical composition. For a chemical graph, the temperature of a vertex is a local property introduced by Fajtlowicz (1988). A temperature-based graphical descriptor is structured based on temperatures of vertices. Involving a non-zero real parameter β\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta$$\\end{document}, the general F-temperature index Tβ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$T_{\\beta }$$\\end{document} is a temperature index having strong efficacy. In this paper, we employ discrete optimization and regression analysis to find optimal value(s) of β\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\beta$$\\end{document} for which the prediction potential of Tβ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$T_{\\beta }$$\\end{document} and the total π\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\pi$$\\end{document}-electron energy Eπ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$E_{\\pi }$$\\end{document} of polycyclic hydrocarbons is the strongest. This, in turn, answers an open problem proposed by Hayat & Liu (2024). Applications of the optimal values for Tβ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$T_{\\beta }$$\\end{document} are presented a two-parametric family of carbon nanocones in predicting their Eπ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$E_{\\pi }$$\\end{document} with significantly higher accuracy.

Molecular descriptors of symmetrically configured carbon nanocones via quotient graph technique

Carbon nanocones, characterized by planar networks primarily consisting of hexagonal carbon faces and a few pentagons in the core, hold significant promise in various fields such as electronics, medicine, and material research due to their exceptional properties. This study exclusively investigates the topological descriptors of symmetrically configured carbon nanocones, specifically nanocones with two and three pentagonal core respectively. By modeling these structures as chemical graphs and employing molecular descriptors, we aim to provide a quantitative analysis of the structures without laboratory experimentation. The quotient graph approach is employed to determine the distance based descriptors, namely wiener, szeged and Padmakar-Ivan indices for these symmetrically configured carbon nanocones. The analytically closed formulas determined could be useful in quantitative structure-property-activity relationship studies, which helps in predicting the physico-chemical properties of the underlying structures. Thus the findings in this work not only deepen our understanding of symmetric carbon nanocones but also pave the way for significant advancements in nanotechnology and materials science.

Torsional properties of spiral carbon nanocones

Carbon nanostructure plays a unique role in advanced nanodevices. This work investigated the torsional properties and underlying mechanisms of spiral carbon nanocones (SCN) via atomistic simulations. The SCN exhibits four deformation stages, including linear elastic, nonlinear elastic, plastic and failure. The elastic phase is characterized by compressive stress at the inner covalent bond and tensile stress at the outer edge. The plastic transition is initiated at the innermost region, accompanied by in-plane folding. The interlayer interactions of the SCN facilitate its capacity to elicit an axial response during torsion. The resulting axial forces are governed by the layer number, cone angle, and the dimensions of both inner and outer radii. Outer radius exerts the most significant influence on SCN via the interlayer contact area. Furthermore, the inner radius and cone angle are intrinsically linked to the structural stiffness of the inner bore, which affects the axial mechanical response of the SCN during the nonlinear elastic and plastic phases. The Pearson correlation coefficient analysis has validated that these two parameters are the most crucial for SCN torsional performance. This work elucidates the prospective utility of SCN as a novel twist-to-push actuator for advanced nanodevices.

Molecular Descriptors Of Certain Class Of Carbon Nanocone Networks Through Quotient Graph Approach

Nanoparticles have potential applications in a wide range of fields, including electronics, medicine and material research, because of their remarkable and exceptional attributes. Carbon nanocones are planar carbon networks with mostly hexagonal faces and a few non-hexagonal faces (mostly pentagons) in the core. Two types of nanocone configurations are possible: symmetric and asymmetric, depending on where the pentagons are positioned within the structure. In addition to being a good substitute for carbon nanotubes, carbon nanocones have made an identity for themselves in a number of fields, including biosensing, electrochemical sensing, biofuel cells, supercapacitors, gas storage devices, and biomedical applications. Their astonishing chemical and physical attributes have made them well-known and widely accepted in the fields of condensed matter physics, chemistry, material science, and nanotechnology. Mathematical and chemical breakthroughs were made possible by the concept of modeling a chemical structure as a chemical graph and quantitatively analyzing the related graph using molecular descriptors. Molecular descriptors are useful in many areas of chemistry, biology, computer science, and other sciences because they allow for the analysis of chemical structures without the need for experiments. In this work, the quotient graph approach is used to establish the distance based descriptors of symmetrically configured two-pentagonal and three-pentagonal carbon nanocones.

An optical study on the enhanced light trapping performance of the perovskite solar cell using nanocone structure

Photon management strategies are crucial to improve the efficiency of perovskite thin film (PTF) solar cell. In this work, a nano-cone (NC) based 2D photonic nanostructure is designed and simulated aiming at achieve superior light trapping performance by introducing strong light scattering and interferences within perovskite active layer. Compared to the planar PTF solar cell, the NC nanostructured device with 45 degrees half apex angle obtains highest short-circuit current density, which improved over 20% from 15.00 mA/cm2 to 18.09 mA/cm2. This work offers an alternative design towards effective light trapping performance using 2D photonic nanostructure for PTF solar cell and could potentially be adopted as the nano-structuring strategy for the future perovskite solar cell industry.

Exploring the mechanism of nerve agent (Tabun and Sarin) adsorption on carbon nanocones: Computational insights

Carbon NanoCones (CNCs), distinguished by their conical shape and large surface area, are evaluated for their potential application in nerve gas [tabun (GA) and sarin (GB)] adsorption. Density Functional Theory (DFT) calculations, Molecular Dynamics (MD), and Monte Carlo (MC) simulations are employed to investigate this phenomenon comprehensively. The study findings indicate that tabun (GA) and sarin (GB) undergo spontaneous adsorption, characterized by significant negative energy values. Density Functional Theory (DFT) calculations indicate electron donation tendencies of nerve agents to CNC surfaces. Computational analysis shows higher adsorption efficiency in the inner portion (P1) of CNCs. Molecular Dynamics (MD) and Monte Carlo (MC) simulations confirm planar adsorption configurations parallel to CNC surfaces. The DFT calculations show that GA has a far greater adsorption energy on a Carbon Nanocone compared to GB (−44.96 kcal/mol for GA, whereas GB has an adsorption energy of −35.95 kcal/mol). Furthermore, the analysis reveals significant differences between Sarin and Tabun nerve agents. Sarin exhibits higher global hardness, indicating increased stability, while Tabun shows higher overall softness, suggesting greater reactivity. Despite similar electronegativities, Sarin’s greater ionization energy and electron affinity imply enhanced stability and reactivity. Differences in HOMO and LUMO energies highlight unique reactivity profiles, with Sarin being more susceptible to nucleophilic attacks and Tabun to electrophilic attack. Sarin’s larger energy gap between HOMO and LUMO orbitals signifies its superior stability under electronic disturbances.

Adsorption, Sensor Properties, AIM Analysis, Docking of an Anticancer Drug Benzamide on Nanocones: SERS, Solvent Effects and DFT Investigation

Using first principles, the electrical response of carbon nanocones (NC) to the drug benzamide (BZE) was investigated using density functional theory (DFT). The adsorption energies of BZE at the nanocone’s bottom (Complex I), side (Complex II), and top (Complex III) are −88.35 kcal/mol, −45.46 kcal/mol and −48.73 kcal/mol. The two other adsorptions, Complexes II and III are physisorption, however, the high value of Eads in the case of Complex I with the drop in bond lengths suggests that Complex I adsorption is chemisorption. The electrical conductivity has risen as a result of the considerable decrease in the nanocone energy gap (from 0.63 eV to 0.61 eV, 0.61 eV and 0.60 eV) caused by the adsorption of BZE. It suggests that the nanocones would be a good fit for the electronic sensors and an appropriate choice for BZE detection. Additionally, the BZE adsorption influences the nanocone’s workfunction, which is reduced by approximately 45.19%, 2.8% and 2.05% for complexes I to III. This suggests that the nanocone could be a workfunction-based sensor for the detection of BZE. The increase in binding affinity in complexes reveals that the nanocones will act as a drug delivery carrier. Theoretically, anticipated Raman spectra of BZE and complexes show SERS activity and inactive normal Raman modes are active in the Raman spectrum of complexes. Compounds II and III exhibit weak noncovalent interactions (NCI) and due to the presence of covalent bonding interaction in compound I, significant changes in other bonding and nonbonding electron densities are observed compared to compounds II and III.

Mathematical analysis of the structure of one-heptagonal carbon nanocone in terms of its basis and dimension

For an undirected connected graph G = G(V, E) with vertex set V(G) and edge set E(G), a subset R of V is said to be a resolving in G, if each pair of vertices (say a and b; a ≠ b) in G satisfy the relation d(a, k) ≠ d(b, k), for at least one member k in R. The minimum set R with this resolving property is said to be a metric basis for G, and the cardinality of such set R, is referred to as the metric dimension of G, denoted by dim v (G). In this manuscript, we consider a complex molecular graph of one-heptagonal carbon nanocone (represented by HCN s ) and investigate its metric basis as well as metric dimension. We prove that just three specifically chosen vertices are enough to resolve the molecular graph of HCN s . Moreover, several theoretical as well as applicative properties including comparison have also been incorporated.

Carbon nanocone mechanical behavior and their use as AFM tips for the characterization of polymers in Peak Force mode

Compared to carbon nanotube-based Atomic Force Microscopy probes, carbon nanocone-based probes appear as promising candidates for investigating topography and mechanical properties thanks to the reduced number of artefacts. In this paper, we intend to investigate some of the mechanical features of carbon nanocone (CnC) tips and to evaluate their performances as probes for investigating the mechanical properties of polymer films and composites. Using their force distance curve, the cantilever/CnC spring constant of several CnC probes is determined and the related bending force for each cone is extracted. The results demonstrate CnC bending forces ranging from 100 nN up to 3 μN, which is up to 2 orders of magnitude higher than values reported in the literature for carbon nanotubes. Moreover, the bending phenomenon occurred only when the CnC axis was not strictly perpendicular to the substrate surface. Using Peak-Force Quantitative NanoMechanical (PF-QNM) mode, we demonstrate that CnC probes are suitable to accurately probe polymer mechanical properties, provided the same targeted deformation is used for both the calibration and PF-QNM measurements.

Van der Waals epitaxy of CsPbBr3/WSe2 heterostructure and dynamics study of exciton recombination

Van der Waals heterostructures formed by inorganic perovskites and transition metal dichalcogenides (TMDCs) have promising applications in photonics and optoelectronics. However, there are few studies on the properties of CsPbBr3/TMDC at low temperatures. Here, we demonstrate van der Waals epitaxy of CsPbBr3 nanowires (NWs), nanoplates (NPs) and nanocones (NCs) on monolayer (ML) WSe2, and investigate the lattice dynamics of the heterostructure at low temperatures using temperature-dependent Raman spectroscopy. In addition, temperature-dependent photoluminescence (PL) spectroscopy shows that the type II band alignment between CsPbBr3 and ML WSe2 leads to a broad emission peak at the low-energy side of the ML WSe2 emission at low temperatures. Meanwhile, a high-energy peak appears near the CsPbBr3 emission below 133 K, which may be related to the phase transition of CsPbBr3 from the cubic to the orthorhombic phase. These findings are important for the development of van der Waals heterostructure based self-powered photodetector with high performance.

TiO2 nanocone photoanodes by Ar ion-beam etching and physics-based electrochemical impedance spectroscopy

TiO2 nanocone (NC) arrays were produced by argon ion beam etching of nanotube (NT) arrays prepared by Ti anodizing. The anti-reflection performance of NC arrays was enhanced by anodizing a 1 μm-thick Ti film deposited on a p-type silicon substrate. The NC morphology was maintained upon heat treatment up to 400 °C, where the anatase phase was formed. Higher temperature treatments resulted in agglomeration and the formation of the rutile phase. The photoelectrochemical performances of the NC and NT arrays on Ti/Si substrates and the NTs on the Ti disk, both annealed at 400 °C, were compared. The photocurrent curves of the samples on Ti/Si were qualitatively different from NT on Ti. Impedance spectroscopy revealed that the response is dominantly from the p-Si substrates, which can be almost ideally described by the diffusion-recombination governed by the minority electronic carriers. NT on Ti can be characterized by the transmission line model for nanoporous electrodes where the transverse and interfacial capacitances are described by Havriliak-Negami capacitance functions with fixed exponents of either 1 and ½ at high- and low-frequency limits. The model then powerfully deconvolutes TiO2 response from the limited information at the low frequencies for NT and NC on Ti/Si, which can be related to the photoelectrochemical performance. Mott-Schottky analysis of well-defined capacitance parameters from the Havriliak-Negami function allows the physics-based description of the spatially and energetically distributed dopant defects in nanostructured materials.

Graph Entropy for Adjacently and Non-Adjacently Configured Pentagonal Structure of Carbon Nanocones

aims: Carbon nanocones possess exceptional properties compared to other nanomaterials, such as nanotubes, graphene etc. Hence they can be used as an alternative to other nanostructures. This work helps in determining various properties of the nanocone structure through topological descriptors. In this paper, various degree based topological descriptors along with its entropy measures are evaluated for adjacently and non-adjacently configured pentagonal structure of carbon nanocones. background: Carbon nanoparticles are gaining much importance in the contemporary world. Among which carbon nanocones have wide range of acceptance in the field of nanotechnology due to its effective properties and applications. Nanocones, also known as nanohorns are carbon networks which are planar in structure and has majority of hexagonal faces along with some nonhexagonal faces, which are most commonly pentagons. Nanocones which include pentagons in their structure can be referred to as adjacently or non- adjacently configured pentagonal structure of nanocones. Various topological descriptors for few nanocone classes were derived by researchers earlier, but not for the class of nanocones in this paper. Through this work, we try to vanish the research gap in this field. objective: : The degree based descriptors and corresponding graph entropies for the adjacently and non-adjacently configured pentagonal structure of nanocones were determined, which further can be applied in quantitative structure – activity – property relationship studies. The concept of graph entropy is to assign a probability function to the edges in the chemical graph using the topological descriptor and it helps to characterise the complexity of graphs. method: We have employed the degree counting method and edge partition based on the vertices and edges of the adjacently and non-adjacently configured pentagonal nanocone structures to obtain the edge partitions and then using the corresponding mathematical expression, the degree based descriptors and its corresponding entropies were determined. result: Result: The analytically closed formulas to compute the degree based topological descriptors and graph entropies for any generation of the class of nanocone structures were obtained. conclusion: In this work, the degree based descriptors and the corresponding graph entropies for the adjacently and non-adjacently configured pentagonal structure of carbon nanocones are determined applying the degree counting method and edge partition based on the vertices and edges. Also a graphical comparative study was also done with the help of obtained results. other: end.

Domination and power domination in a one-pentagonal carbon nanocone structure.

Domination is an important factor in determining the robustness of a graph structure. A thorough examination of the graph's topological structure is necessary for analyzing and examining it for various aspects. Understanding the stability of a chemical compound is a significant criterion in chemistry, which necessitates conducting numerous experimental tests. The domination number and power domination number are pivotal in defining a wide range of physical properties, which include physiochemical properties, thermodynamic properties, chemical activities, and biological activities. The one-pentagonal carbon nanocone (1-PCNC) is a member of the carbon nanocone family and has a structure similar to that of honeycomb networks, which are renowned for their robustness. In this paper, we find the domination number and power domination number of 1-PCNC by considering it as an (m-1)-layered infinite graph.

Abnormal blockage of water flow in valveless nanopumps

In the narrow orifice of a cone-shaped channel, blockage can occur for granular matter. However, water molecules can enter into and even permeate through carbon nanotubes of diameters down to 0.8 nm at ultrafast rates. Here we demonstrate by molecular dynamics simulations that clogging can also emerge unexpectedly in the water flowing through a nanoscale valve-less pump. The designed pump features two truncated carbon nanocones, with the narrowest region having a diameter of 1.2 nm (larger than that of (6, 6) carbon nanotube), linked to a fluid cavity volume, and is powered by the vibration of a graphene sheet. In the low frequency range, water molecules can be driven through the nanocones effectively by the vibration of the graphene sheet. The maximum flux reaches 83 ns<sup>–1</sup>, which is approximately 20 times the measured value of (3.9 ± 0.6) ns<sup>–1</sup> for aquaporin-1. However, at higher frequencies, water molecules suffer blockage at the narrow exits. Much unlike granular matter, high-frequency vibration cannot restore water flow. The key to this phenomenon is that in the narrow exits of two nanocones acting as diffuser/nozzle, the number density of water molecules rapidly increases with frequency increasing, the tight hydrogen-bonding network is formed, and the mean lifetime of hydrogen bonds increases dramatically under high-frequency vibrations. High frequency fluctuations in the middle chamber make H-bond network between water molecules in the narrow exits more stable. The probability density distribution of water exhibits a non-equilibrium transition from a disordered state to ordered state. This work reveals a new mechanism of water flowing/blocking in a nanoscale valve-less pump based on two asymmetrical nanocones, offers valuable insights into understanding nonequilibrium jamming transition in nanoscale fluid.

Enhanced HER Efficiency of Monolayer MoS2 via S Vacancies and Nano-Cones Array Induced Strain Engineering.

Molybdenum disulfide (MoS2) has gained significant attention as a promising catalyst for hydrogen evolution reaction (HER). The catalytic performance of MoS2 can be enhanced by either altering its structure or regulating external conditions. In this study, a novel approach combining the introduction of sulfur vacancy (VS) and biaxial tensile strain to create more active sites and modulate the band structure of monolayer MoS2 is proposed. To achieve the desired strain level, nano-cones (NCs) array substrates facilely fabricated by dip-pen nanolithography (DPN) are employed. The magnitude of the applied tensile strain can be finely tuned via adjusting the height of the NCs. Furthermore, on-chip electrochemical devices are constructed based on artificial structures, enabling precise optimization of HER performance of MoS2 through the synergistic effect of VS and strain. Combined with the d-band theory, it reveals that the HER properties of VS-MoS2 are highly dependent on the degree of tensile strain. This study presents a promising avenue for the design and preparation of high-performance 2D catalysts for energy conversion and storage applications.

Exploring porphyrins induced carbon nanocone TM-PICNC (TM = Sc2+, Ti2+, V2+, Cr2+, Fe2+, Co2+, Ni2+, Cu2+, and Zn2+) as a highly sensitive sensor for CO2 gas detection in presence O2 and H2O molecules: a computational study

This study investigated the adsorption of CO2 molecules on transition metal ions (TM) porphyrins induced carbon nanocone (TM-PICNC) (TM = Sc2+, Ti2+, V2+, Cr2+, Fe2+, Co2+, Ni2+, Cu2+, and Zn2+) using density functional theory (DFT) to determine the stabilities, energetic, structural, and electronic properties. The results showed that the CO2 molecule is adsorbed on TM-PICNC with adsorption energies ranging from 0.03 to −12.12 kcal/mol. The weak interactions of CO2 gas with Cr, Ni, Cu, and Zn-PICNC were observed, while strong adsorption was found on Sc, Ti, and V-PICNC. The Ti, V, and Cr-PCNC structures were shown to have a suitable energy gap (Eg) for sensing ability because of the effective and physical interaction between these structures and CO2 gas, leading to a short recovery time. DFT calculations also revealed that V-PCNC had a high %ΔEg (about %56.79) and hence high sensitivity to CO2 gas, making it a promising candidate for having good sensing ability to CO2 gas in presence of O2 and H2O gas.

Synergistic effect on silicon surface under low energy he ion irradiation at elevated temperatures

One of the major challenges in nuclear fusion, nanolithography, and various industries is the effect of low energy ion irradiation on the surface morphology of materials. For example, the effect of low energy irradiation on plasma-facing materials' lifetime in fusion reactors, the effect on the optical systems in nanolithography laser produced plasma devices, and the effect on mass production of effective and flexible anti-reflecting coatings in photovoltaic (PV) industry. Silicon and carbides in particular, showed interest in nuclear fusion as potential wall materials, as in mirror designs for nanolithography devices, and as coatings in PV system components. Recently innovative novel Si nanostructures such as nanocones (NCs) demonstrated great feasibility in several areas including the next generation PV cells, batteries, supercapacitors, nano-optoelectronics, photonics, and energy storage devices. Their unique electronic properties and significantly higher absorption over a wide broadband range, offer paramount potential in various fields including microelectronics, optoelectronics, photonics, photovoltaics, biology, sensors, templet for selective growth (on nanostructured substrates), fast electronic devices, and even in high- density data storage. We tailor Si NCs using simultaneous low energy helium (He) ion irradiation on planar Si (111) and (100) and Ta metal masks. In a series of successive experiments, three key parameters, temperature, flux, and presence of Ta metal impurity, were tuned to study the progression of nanostructure development, as well as the effect of these nanostructures on key material properties. Before performing He ion sputtering experiments, 100 eV Ar+ ion irradiations, for 10 min duration, were also performed in-situ in each case for removing any preexisting SiO2 form planer Si substrates. Clear and distinctive progressions of NC development were found during the tuning of each parameter. During the temperature dependent studies, we clearly observed a sequential progression from thicker and less dense cones (773 K) to finer and more densely packed NCs (1073 K). On the other hand, during the case of flux dependent studies, it was found that increasing flux increases the size of the NCs, with low flux resulting in sparsely placed nanodots, and high fluxes resulting in large conglomerates. Finally, the effect of Ta impurity shows an increased propensity for NCs development. In addition, using optical-reflectivity studies we clearly observed a significant reduction (from ∼65 to almost zero) in optical reflectivity.

An efficient HCN gas sensor by functionalized, decorated, and doped carbon nanocone strategy: A theoretical study

An efficient HCN gas sensor by functionalized, decorated, and doped carbon nanocone strategy: A theoretical study

A quantum mechanical investigation of nanocone oxide as a drug carrier for zidovudine: AIDS drug

Traditionally, nanocones as a drug delivery material allow controlled drug delivery close to the target area while reducing the toxicity and generic accumulation associated with traditional intravenous injection methods. In the current study, density functional theory (DFT) is employed to investigate the therapeutic potential of carbon nanocone oxide (ONC) as a carrier with zidovudine drug for the treatment of human immunodeficiency virus (HIV). The electronic ground state and excited state were studied to evaluate the drug carrier potential of ONC and Zidovudine-ONC complex. The Frontier Molecular Orbitals (FMOs) and Molecular Electrostatic Potential (MEPs) revealed that the ONC carrier acts as a donor and zidovudine as an acceptor. The FMOs confirmed the interaction between drug and carrier stabilization energy by calculating chemical hardness, material softness, electronegativity, Ionization energy and electron affinity. The natural bond analysis (NBO), non-covalent interaction (NCI) and electron localization function (ELF) revealed the charge transfer between zidovudine and ONC. The density of state (DOS) and Charge Deposition analysis (CDA) provided the charge transfer. To study the excited state of zidovudine, transition density matrix (TDM), UV(Ultra-visible), IR (infrared), Raman, and NMR (Nuclear Magnetic Resonance) spectra of ONC and zidovudine-ONC complex have been plotted. The spectra showed a significant red shift in the zidovudine-ONC complex. Photoinduced electron studies (PET) showed fluorescence quenching because of the interaction between the drug and the carrier and provided a graphical explanation of the distinct excited state. All the results show that the ONC carrier has therapeutic potential as a zidovudine carrier for the treatment of Human Immunodeficiency Virus (HIV).

Water repellence of biomimetic structures fabricated via femtosecond laser direct writing

Femtosecond laser direct writing based on two-photon polymerization (TPP), which is a sub-classification of vat photopolymerization, has the advantages of unlimited geometrical freedom and high resolution, and has attracted significant interests from scientists and engineers in recent years. In the present study, TPP fabrication was performed using a laser equipment with wavelength of 514 nm. The collimated beam diameter before the focusing lens was measured as 5 mm and the focused laser spot diameter was calculated as 280 nm. Key TPP processing parameters were investigated for the fabrication of nanowires, and micro/ nanoscale biomimetic structures, including cone and pinecone structures. The finest nanowire has a diameter of 105 nm and is achieved at the laser power of 0.8 μW (near the laser polymerization threshold). For the three-dimensional (3D) structures, laser power, layer thickness and hatch spacing would influence the fabrication accuracy. Generation of a stiff 3D cone structure would require a minimum laser power of 1.4 μW when the hatch spacing and layer thickness are 200 nm. The optimum processing parameters (laser power 2.2 μW, hatch space and layer thickness 100 nm) can generate structures with dimensions close to the design values. For pinecones with nano features, the scanning strategies play a significant role in the nano fabrication accuracy. A row of pinecones and cones were fabricated and tested for their water repellence performance. The relationship between the performance and the nano cone density was investigated. The pinecone structures exhibit superior performance to the ones with no nano-scale structures, indicating that improved hydrophobicity can be achieved by designing the micro/nano hierarchical structures. The increased number density of the nano cones in a micro/nano hierarchical structure was found to profoundly enhance the water repellence of the structures. The mechanisms were discussed with Wenzel and Cassie models.