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(1) Background: Angiotensin-converting enzyme 2 (ACE2) is a crucial functional receptor of the SARS-CoV-2 virus. Although the scale of infections is no longer at pandemic levels, there are still fatal cases. The potential of the virus to infect the skin raises questions about new preventive measures. In the context of anti-SARS-CoV-2 applications, the interactions of antimicrobial nanomaterials (silver, Ag; diamond, D; graphene oxide, GO and their complexes) were examined to assess their ability to affect whether ACE2 binds with the virus. (2) Methods: ACE2 inhibition competitive tests and in vitro treatments of primary human adult epidermal keratinocytes (HEKa) and primary human adult dermal fibroblasts (HDFa) were performed to assess the blocking capacity of nanomaterials/nanocomplexes and their toxicity to cells. (3) Results: The nanocomplexes exerted a synergistic effect compared to individual nanomaterials. HEKa cells were more sensitive than HDFa cells to Ag treatments and high concentrations of GO. Cytotoxic effects were not observed with D. In the complexes, both carbonic nanomaterials had a soothing effect against Ag. (4) Conclusions: The Ag5D10 and Ag5GO10 nanocomplexes seem to be most effective and safe for skin applications to combat SARS-CoV-2 infection by blocking ACE2-S binding. These nanocomplexes should be evaluated through prolonged in vivo exposure. The expected low specificity enables wider applications. [ABSTRACT FROM AUTHOR]

Diamond nanoparticles/urethane-based bio-adhesives (ND-U-BA) were synthesized via in-situ polymerization. Chemical structure and curing kinetics of the samples were studied by Fourier-transform infrared spectroscopy. Results showed NDs controlled the curing profile of samples. Thermal and crystalline properties were studied using differential scanning calorimetry and X-ray diffraction analyses. Results indicated hard segments had higher ordering levels in the presence of NDs which is due to the lower hydrogen bonding among polyurethane chains. Mechanical results showed ND-U-BA had higher adhesion strength due to the formation of chemical crosslinks and a controlled curing mechanism. MTT and biodegradation studies showed ND-U-BA had acceptable cell viability and degradation content. • Urethane and diamond nanoparticles/urethane-based bio-adhesives were synthesized. • Results showed ND nanoparticles had controlling effect on curing kinetic of samples. • Cell viability of bio-adhesives was improved with the ND nanoparticles' addition. • Incorporation of ND nanoparticles increased the adhesion strength of bio-adhesive. [ABSTRACT FROM AUTHOR]

A study of the role of diamond nanoparticles on 5CB liquid crystal composites with Fe3O4 nanoparticles is presented. Composite ferronematic systems based on the nematic liquid crystal 5CB doped with Fe3O4 magnetic nanoparticles and additionally bound to diamond nanoparticles (DNPs), of a volume concentration of 3.2 mg/mL, 1.6 mg/mL and 0.32 mg/mL, were investigated using both magneto-optical effect and surface acoustic waves (SAWs) to study the role of diamond nanoparticles on the structural properties of ferronematic liquid crystals. The responses of light transmission and SAW attenuation to an external magnetic field were investigated experimentally under a linearly increasing and decreasing magnetic field, respectively. Investigations of the phase transition temperature shift of individual composites were also performed. The experimental results highlighted a decrease in the threshold field in the ferronematic LC composites compared to the pure 5CB as well as its further decrease after mixing Fe3O4 with diamond powder. Concerning the transition temperature, its increase with an increase in the volume fraction of both kinds of nanoparticles was registered. The role of diamond nanoparticles in the structural changes and the large residual light transition and/or attenuation (memory effect) were also observed. The presented results confirmed the potential of diamond nanoparticles in nematic composites to modify their properties which could lead to final applications. [ABSTRACT FROM AUTHOR]

(1) Background: Angiotensin-converting enzyme 2 (ACE2) is a crucial functional receptor of the SARS-CoV-2 virus. Although the scale of infections is no longer at pandemic levels, there are still fatal cases. The potential of the virus to infect the skin raises questions about new preventive measures. In the context of anti-SARS-CoV-2 applications, the interactions of antimicrobial nanomaterials (silver, Ag; diamond, D; graphene oxide, GO and their complexes) were examined to assess their ability to affect whether ACE2 binds with the virus. (2) Methods: ACE2 inhibition competitive tests and in vitro treatments of primary human adult epidermal keratinocytes (HEKa) and primary human adult dermal fibroblasts (HDFa) were performed to assess the blocking capacity of nanomaterials/nanocomplexes and their toxicity to cells. (3) Results: The nanocomplexes exerted a synergistic effect compared to individual nanomaterials. HEKa cells were more sensitive than HDFa cells to Ag treatments and high concentrations of GO. Cytotoxic effects were not observed with D. In the complexes, both carbonic nanomaterials had a soothing effect against Ag. (4) Conclusions: The Ag5D10 and Ag5GO10 nanocomplexes seem to be most effective and safe for skin applications to combat SARS-CoV-2 infection by blocking ACE2-S binding. These nanocomplexes should be evaluated through prolonged in vivo exposure. The expected low specificity enables wider applications.

Mateusz Wierzbicki,1 Katarzyna Zawadzka,1 Barbara Wójcik,1 Sławomir Jaworski,1 Barbara Strojny,1 Agnieszka Ostrowska,1 Artur Małolepszy,2 Marta Mazurkiewicz-Pawlicka,2 Ewa Sawosz1 1Department of Nanobiotechnology, Institute of Biology, Warsaw University of Life Sciences, Warsaw, 02-786, Poland; 2Faculty of Chemical and Process Engineering, Warsaw University of Technology, Warsaw, 00-654, PolandCorrespondence: Mateusz Wierzbicki, Department of Nanobiotechnology, Institute of Biology, Warsaw University of Life Sciences, Ciszewskiego 8, Warsaw, 02-786, Poland, Tel +48 22 5936676, Email mateusz_wierzbicki@sggw.edu.plIntroduction: Diamond nanoparticles are considered to be one of the most cytocompatible carbon nanomaterials; however, their toxicity varies significantly depending on the analysed cell types. The aim was to investigate the specific sensitivity of endothelial cells to diamond nanoparticles dependent on exposure to nanoparticles.Methods: Diamond nanoparticles were characterized with Raman spectroscopy, Fourier-transform infrared spectroscopy (FTIR) and dynamic light scattering (DLS). Toxicity of diamond nanoparticles was assessed for endothelial cells (HUVEC), human mammary epithelial cells (HMEC) and HS-5 cell line. The effect of diamond nanoparticles on the level of ROS, NO, NADPH and protein synthesis of angiogenesis-related proteins of endothelial cells was evaluated.Results and Discussion: Our studies demonstrated severe cell type-specific toxicity of diamond nanoparticles to endothelial cells (HUVEC) depending on nanoparticle surface interaction with cells. Furthermore, we have assessed the effect on cytotoxicity of the bioconjugation of nanoparticles with a peptide containing the RGD motive and a serum protein corona. Our study suggests that the mechanical interaction of diamond nanoparticles with the endothelial cell membranes and the endocytosis of nanoparticles lead to the depletion of NADPH, resulting in an intensive synthesis of ROS and a decrease in the availability of NO. This leads to severe endothelial toxicity and a change in the protein profile, with changes in major angiogenesis-related proteins, including VEGF, bFGF, ANPT2/TIE-2, and MMP, and the production of stress-related proteins, such as IL-6 and IL-8.Conclusion: We confirmed the presence of a relationship between the toxicity of diamond nanoparticles and the level of cell exposure to nanoparticles and the nanoparticle surface. The results of the study give new insights into the conditioned toxicity of nanomaterials and their use in biomedical applications.Keywords: diamond nanoparticles, endothelial cells, nanotoxicity, oxidative toxicity

Electrochemical coatings of chromium modified with diamond nanoparticles applied directly on niobium-aluminum alloy were obtained. Diamond nanoparticles produced by detonation synthesis were used. Chromium coatings were deposited on a monolithic composite with a complex structure based on niobium and aluminum alloys, called later matrix for short. Standard chromium electrolyte and electrolyte with diamond nanoparticles concentration of 10 g/L were used. The surface morphology of the chromium coating was investigated with an atomic force microscope and NanoScope V system (Bruker Inc., Germany). Analyzes were performed by scanning electron microscope, Bruker Inc. system and PolyvarMet metallographic microscope. The microhardness was measured using PolyvarMet 4000 microhardness tester. The obtained results of the microhardness are 6800 MPa in the chromium layer and 1400 and 6400 MPa in the matrix. The average thickness of the chromium coatings modified with diamond nanoparticles is 40–45 µm. [ABSTRACT FROM AUTHOR]

Reports on the cytotoxicity of diamond nanoparticles (ND) are ambiguous and depend on the physicochemical properties of the material and the tested cell lines. Thus, the aim of this research was to evaluate the influence of thirteen types of diamond nanoparticles, differing in production method, size, and surface functional groups, on their cytotoxicity against four tumor cell lines (T98G, U-118 MG, MCF-7, and Hep G2) and one non-tumor cell line (HFF-1). In order to understand the dependence of diamond nanoparticles on physicochemical properties, the following parameters were analyzed: viability, cell membrane damage, morphology, and the level of intracellular general ROS and mitochondrial superoxide. The performed analyses revealed that all diamond nanoparticles showed no toxicity to MCF-7, Hep G2, and HFF-1 cells. In contrast, the same nanomaterials were moderately toxic for the glioblastoma T98G and U-118 MG cell lines. In general, the effect of the production method did not influence ND toxicity. Some changes in cell response after treatment with modified nanomaterials were observed, with the presence of carboxyl groups having a more detrimental effect than the presence of other functional groups. Although nanoparticles of different sizes caused similar toxicity, nanomaterials with bigger particles caused a more pronounced effect. [ABSTRACT FROM AUTHOR]

Electrochemical chromium coatings modified with nanodiamond particles were deposited directly on a monolithic composite with a layered structure. Diamond nanoparticles obtained by detonation synthesis were used. The chromium coatings were deposited on a monolithic composite with a complex structure based on molybdenum and aluminum alloys. This monolithic composite will be called "matrix" for short. X-ray diffraction analysis of the matrix and the coating was performed with powder X-ray diffractometer (XRD). Concentrations of nanodiamond particles of 10–15 g/L in the chromating electrolyte were used. Analyses of scanning electron microscope (SEM) of Bruker Inc. were performed. The microstructure was studied with a Polyx Met metallographic microscope at 200× magnification and ProgRes CT3 USB digital camera and a licensed ProgRes CapturePro software. The microhardness was measured using a PolyvarMet 4000 microhardness tester. In the chromium layer it is in the range 620–750 kg/mm2 and in the matrix in the range 1000–1140 kg/mm2. The thickness of the chromium coatings with nanodiamond particles is between 45–50 µm. [ABSTRACT FROM AUTHOR]

In this work, we present and characterize a microwave plasma microtorch that can support the formation of diamond nanoparticles (DNPs) in the gas phase when using hydrogen‐methane as a precursor gas. We first showed how the nonequilibrium character of the plasma obtained in this microtorch ensures enhanced H‐atom, C2 ${{\rm{C}}}_{2}$, and CH3 ${\text{CH}}_{3}$ production at moderate gas temperature levels that provides thermal stability of DNPs. The material characterization by TEM, Raman, and electron energy loss spectroscopy spectra confirm the presence of a substantial amount of diamond phase in the carbon dust particles collected from the plasma phase. Investigation of the effects of injected microwave power on the process characteristics showed a direct correlation between enhanced C2 ${{\rm{C}}}_{2}$ production and the appearance of the diamond phase, which points out the critical role of C2 ${{\rm{C}}}_{2}$ as far as gas‐phase nucleation of DNPs is concerned. [ABSTRACT FROM AUTHOR]

A study of the role of diamond nanoparticles on 5CB liquid crystal composites with Fe3O4 nanoparticles is presented. Composite ferronematic systems based on the nematic liquid crystal 5CB doped with Fe3O4 magnetic nanoparticles and additionally bound to diamond nanoparticles (DNPs), of a volume concentration of 3.2 mg/mL, 1.6 mg/mL and 0.32 mg/mL, were investigated using both magneto-optical effect and surface acoustic waves (SAWs) to study the role of diamond nanoparticles on the structural properties of ferronematic liquid crystals. The responses of light transmission and SAW attenuation to an external magnetic field were investigated experimentally under a linearly increasing and decreasing magnetic field, respectively. Investigations of the phase transition temperature shift of individual composites were also performed. The experimental results highlighted a decrease in the threshold field in the ferronematic LC composites compared to the pure 5CB as well as its further decrease after mixing Fe3O4 with diamond powder. Concerning the transition temperature, its increase with an increase in the volume fraction of both kinds of nanoparticles was registered. The role of diamond nanoparticles in the structural changes and the large residual light transition and/or attenuation (memory effect) were also observed. The presented results confirmed the potential of diamond nanoparticles in nematic composites to modify their properties which could lead to final applications.

In this work, the microstructure, mechanical properties, and corrosion behavior of the Mg-1Zn-0.6Ca matrix alloy (ZX10), reinforced by adding various amounts of nanodiamond particles (0.5, 1, and 2 wt.%), prepared by the ultrasound-assisted stir-casting method, were investigated as they are deemed as potential implant materials in biomedical applications. Microstructure, nanoindentation, mechanical tensile, immersion, and potentiodynamic polarization tests were performed for evaluating the influence of the addition of nanodiamond particles on the alloy's mechanical and biocorrosion properties. The results revealed that the addition of nanodiamond particles causes a reduction in the alloy's grain size. The alloy's nanohardness and elastic modulus values increased when the amount of added nanodiamond particles were increased. The nanocomposite with an addition of 0.5% ND showed the best composition with regard to an acceptable corrosion rate as the corrosion rates are too high with higher additions of 1 or 2% NDs. At the same time, the yield strength, tensile strength, and elongation improved slightly compared to the matrix alloy. [ABSTRACT FROM AUTHOR]

[Display omitted] • Advanced Electrochemical Sensing of Cyanuric Acid (CYA) • Synergistic effect of WS 2 , Copper and Diamond Nanoparticles for CYA determination. • The sensor allows CYA determination in a swimming pool water sample with very good recoveries. In the present study, we demonstrate the synergistic effect of copper nanoparticles, tungsten disulfide, and diamond nanoparticles on the electrochemical detection of cyanuric acid, a compound conventionally employed for disinfection in aquatic recreational facilities such as swimming pools. First, copper nanoparticles were synthesized in-situ on a glassy carbon electrode through the electrochemical reduction of copper nitrate and their response towards cyanuric acid was assessed. In order to improve this response, we evaluated the inclusion of transition metal dichalcogenides nanosheets (MoS 2 , ReS 2 or WS 2), as well as diamond nanoparticles in the electrochemical sensor construction. These nanomaterials were incorporated onto the electrode via drop-casting from their respective suspensions. Specifically, the 2D transition metal dichalcogenide suspensions were obtained through a top-down exfoliation method, facilitated by ultrasonic assistance. After optimizing the arrangement of nanomaterials on the glassy carbon electrode to enhance cyanuric acid detection, we characterized the morphology of the resulting surfaces at each stage of electrode surface modification by atomic force microscopy and scanning electron microscopy. The optimized methodology revealed that the sensor response exhibited a linear relationship with cyanuric acid concentrations ranging from 0.077 to 0.70 mM with a detection limit of 23 µM. The sensor was applied to cyanuric acid determination in a swimming pool water sample, obtaining very good recoveries. The results are in good agreement with those obtained by HPLC-UV–vis measurements. [ABSTRACT FROM AUTHOR]

A possibility of laser printing of single diamond nanoparticles with luminescent SiV centers is demonstrated. To provide the transfer, a target consisting of a transparent sapphire plate and an absorbing thin titanium film (600 nm thick) coated with nanoparticles was irradiated with a KrF excimer laser ("lambda"=248 nm, "tau"=20 ns). Optimal values of the laser fluence have been determined and a technique for applying labels for the targeted transfer of nanoparticles has been developed. Luminescence mapping of the donor and the receiving substrates confirmed the transfer of diamond nanoparticles with SiV centers.

Distribution transformers (DTs) are deemed as one of the major and high-priced equipment of electrical grids and their destruction negatively affects the stability and security of the network. The insulation status of the transformer depends on the hotspot and oil temperatures. Accordingly, controlling and, if possible, reduction of transformer oil temperature will improve the insulation status. In this paper, the effect of using nano-oil on oil temperature and loading capacity increment (LCI) of DTs has been studied via the electro-thermal resistance model (E-TRM). The studied nanofluids are two volumetric concentrations of multi-walled carbon nanotubes (MWCNTs) and three volumetric concentrations of diamond nanoparticles dispersed in pure mineral oil (MO). First, the numerical results gained from the E-TRM method are compared and verified with the experiential results of a 500 kVA DT. As well as, the effect of using MWCNT, diamond and proposed ONF nanoparticles in the heat transfer capacity of the transformer are investigated and compared. The results demonstrate that the highest temperature reduction in comparison with MO among the studied nanofluids is about 1 °C and for nanofluid ODI2. While the use of hypothetical ONF nanofluid reduces the oil temperature by 2.7 °C. Finally, the LCI of DTs caused by the use of nanofluids is investigated by the proposed novel equation. The use of nanofluids, especially the proposed ONF nanofluid, leads to the LCI up to 5%.

Diamond nanoparticles (DNPs) are expected as splendid coating materials to give, e.g. corrosion resistance, anti-bacterial properties, and antireflection function. In this paper, we demonstrate a technique of electrostatic layer-by-layer deposition of DNPs onto substrate surfaces using DNP colloidal suspensions with different signs of zeta potentials alternately. The formed DNP layers are investigated in terms of film thickness, surface roughness, and homogeneity. Plus, those morphologies of DNP layers are theoretically correlated with the colloidal properties of DNP suspensions based on the electrostatic interaction potential energy between colloidal DNPs and substrate surfaces. Consequently, it turns out that the demonstrated technique enables formation of DNP thin layers with desired thickness, particle density, and surface roughness on substrate surfaces by controlling the ionic strength of colloidal DNPs.

This study developed a nanosensor for the detection and determination of favipiravir, a presumed drug that has potential therapeutic efficacy in treating COVID‐19 patients, from tablets and serum samples. This nanosensor was obtained by adding the optimum amount of diamond nanoparticles into carbon paste. For the determination of favipiravir adsorptive stripping differential pulse (AdSDPV) and adsorptive stripping square wave voltammetry (AdSSWV) were used. Limit of detection values were found as 4.83×10−9 M and 2.44×10−7 M for bulk and 5.18×10−8 M and 4.38×10−8 M for serum samples using AdSDPV and AdSSWV, respectively. Recovery studies made of the tablet and serum produced satisfactory results. [ABSTRACT FROM AUTHOR]

An iron-matrix powder metallurgy composite with diamond nanoparticle suspension was synthesized to improve the tribological performance of hydraulic components. Based on the theory of suspension flow, filtration and material properties, a mathematical model for predicting the seepage mechanism was established, which was validated by experiments. Furthermore, effects of inlet concentration of diamond nanoparticles and porosity on the seepage characteristics were investigated and results demonstrated that these two parameters have an important effect on the seepage time and total weight gain of diamond nanoparticles. The optimum region of inlet concentration and initial porosity was obtained under different inlet pressure, which is important to select parameters in the design of the composites. [ABSTRACT FROM AUTHOR]

Background & Aims: In the last decade, diamond nanoparticles (DI-NPs) have gained considerable attention in both industries such as medicine and academia. Numerous studies have used various nanoparticles, including diamond nanoparticles, as drug carriers, but the direct effect of diamond nanoparticles on different cell lines, including breast cancer cells (MCF-7) and lymphocyte, is obscure. Therefore, in this study, we investigated and compared the effect of diamond nanoparticles on the cells of breast cancer cells (MCF-7) and human lymphocyte. Some authors have pointed to the destructive effect of DI-NPs on red blood cells. These studies revealed that the characteristics of blood cells, including red blood cells change during the incubation of whole human blood samples with the suspension of DI-NPs in vitro. Blood cell aggregation and their ability to deform are among the most considerable changes that these cells experience. The mechanisms responsible for this effect may be based on the interaction of Nanodiamonds with red blood cells directly or with plasma proteins such as albumin, the major molecular component of blood plasma, indirectly. Numerous studies have been conducted to investigate the effect of nanoparticles on the protein structure of albumin. However, a detailed study has not been performed to investigate the binding mechanisms and the exact interaction of DI-NPs with albumin protein, as well as to compare the effect of DI-NPs on healthy cells and cancer cells. Therefore, this study aimed to investigate the interaction of albumin protein with DI-NPs using spectroscopic methods and comparing the effect of DI-NPs on the viability of lymphocytes and cancer cells. Methods: Cells were cultured in a 96-well culture plate and treated with different concentrations of DI-NPs (0, 1, 10, 20, 50, 100 µg / ml) for 24 hours. Then, 10 µL of MTT solution were added to the cells. After four hours of holding in a 37 ° incubator, the reaction was stopped by adding DMSO solution, and finally, the adsorption rate was measured by an ELISA plate reader at 570 nm. Lactate dehydrogenase test: Cells were treated in a 24-well culture plate with specific concentrations of DI-NPs for 24 hours. The activity of the LDH enzyme in the supernatant and cell lysed was measured using the Pars Azmoun LDH diagnostic kit. Cells were cultured in a 96-well culture plate and treated with DI-NPs for 24 hours. Next, cells were precipitated and washed with PBS solution; after that 100 μl of cell solution with 1 μl of Acridine Orange-Ethidium Bromide dye, the mixture was kept at laboratory temperature for 5 minutes. In the final step, 10 µL of cell suspension were placed on a slide and examined by fluorescence microscopy. Fluorescence measurements were recorded on a fluorescence spectrophotometer. To do so, 2 μM protein solution concentration and different concentrations of DI-NPs (0, 1, 5, 10, 15, 20 μg/ml) were used. The excitation wavelength was set at 270 nm and the emission rate was measured in the range of 300-400 nm. Three sets of fluorescence measurements were recorded at 310, 298, and 315 ° K for different concentrations of DI-NPs. To record the Spectra, a spectropolarimeter was used, and in the ultraviolet region ranging from 190 nm to 260 nm measurements were performed. 2 micromolar protein solution concentration and different concentrations of nanoparticles (0, 1, 5, 10, 15, 20 μg/ml) were utilized. It is also worth mentioning, the experiments were done in the presence and absence of nanoparticles. Measurements were recorded after at least 2 minutes of incubation required for the interaction between DI-NPs and albumin protein. Results: After exposure of lymphocytes and breast cancer cells (MCF-7) to DI-NPs, a decrease in cell survival was observed in breast cancer cells (MCF-7), however, no significant reduction was observed in the viability of lymphocyte cells. When Nanoparticle cytotoxicity started at a concentration of 20 μg / ml, cell viability decreased by 25-21% (p<0.05) compared to the control group; accordingly, cytotoxicity on breast cancer cells increased with increasing nanoparticle concentration. At a concentration of 50 and 100 μg/ml, the survival rate of cancer cells decreased 53.2% - 49.3% (p<0.01) and 68.4% - 64.3% (p<0.001), respectively compared to the control group. Therefore, MTT test results confirmed a concentration-dependent decrease in cancer cell viability. The results also showed that the leakage of LDH enzyme from breast cancer cells (MCF-7) is concentration-dependent. For instance, at the concentrations of 20, 50 and 100 μg / ml the leakage rate of LDH enzyme increased 145.82 ± 10.56 % (p<0.05), 160.76 ± 12.34 % (p<0.01), and 170.46 ± 11.43 % (p<0.001) respectively compared to the control group. the highest rate of lactate dehydrogenase leakage and cell damage was observed at a concentration of 100 μg/ml (Figure 2). The outcomes of the Akredin Orange / Ethidium Bromide test demonstrated that DI-NPs lead to compaction and fragmentation of cellular DNA and induce apoptosis in cancer cells (MCF-7), while no significant effect was spotted on healthy cells. The fluorescence spectroscopy’s results showed a shift towards shorter wavelengths and a decrease in the maximum emission intensity due to the increase in nanoparticle concentration, indicating an increase in protein surface hydrophobicity and displacement of aromatic amino acids to albumin protein level due to increased nanoparticle concentration. The fluorescence spectrum of albumin protein at 298, 310, 315° K declined with increasing concentration of DI-NPs. Therefore, it can be inferred that the DI-NPs led to quenching and suppression of albumin protein. The binding mechanism between albumin protein and DI-NPs is presented using the Stern-Volmer diagram in Figure - 5. As shown in Table 1, while the temperature increases, the Stern Volmer constant decreases. The inverse relationship between temperature and Stern-Volmer constant implies a static bond between DI-NPs and albumin protein. Therefore, it can be concluded that DI-NPs are complexed with albumin protein and the type of quenching mechanism of albumin nanoparticles with albumin protein is static quenching. The CD spectrum of a protein shows information about the secondary structure of the protein. Figure 6 illustrates that the albumin protein has a peak at 208 and 222 nm, indicating the Alpha-Helix structure of the albumin protein. With the increasing concentration of DI-NPs, the structure of albumin protein changes to the random coil structure. Consequently, DI-NPs change the structure of albumin protein from alpha-helix to random coil. Although the melting point of albumin protein is 61°C (see Figure - 7), this temperature changed to 58°C in the presence of diamond nanoparticles, which indicates a decrease in albumin protein stability. Conclusion: In this study, breast cancer cell lines (MCF-7) and lymphocyte cell lines were used to evaluate the toxicity of diamond nanoparticles. The results showed that nanoparticles lead to increased leakage of lactate dehydrogenase in breast cancer cells (MCF-7); while, no enzyme leakage was observed in lymphocyte cells. The results of the apoptosis test confirmed the induction of cell apoptosis in cancer cells, whereas the induction of apoptosis in lymphocyte cells produced no effect. Additionally, the structure of albumin protein in the presence of DI-NPs was investigated by a series of techniques. UV-vis spectroscopy shows an obvious change in the secondary structure of albumin protein after binding to diamond nanoparticles. UV-vis and CD spectroscopy reveal that the structural properties of albumin protein are not preserved in the collection of DI-NPs with albumin protein. Fluorescence spectroscopy shows that the amino acid tryptophan in albumin protein is placed in a more hydrophobic environment in a set of DI-NPs with albumin protein, indicating that protein expansion is likely to occur. The results confirm that DI-NPs can greatly alter the structural properties of albumin protein in the collection of DI-NPs with albumin protein. Therefore, the use of DI-NPs in medical applications needs further study. [ABSTRACT FROM AUTHOR]

Shawqi H Alawdi,1,2 Housam Eidi,3 Marwa M Safar,4,5 Mosaad A Abdel-Wahhab6 1Department of Pharmacology, Faculty of Medicine and Health Sciences, Thamar University, Dhamar, Yemen; 2Department of Pharmacy Practice, Faculty of Pharmacy, University of Science and Technology, Sana’a, Yemen; 3Department of Ophthalmology and Visual Sciences, University of British Columbia, Vancouver, Canada; 4Pharmacology and Toxicology Department, Faculty of Pharmacy, Cairo University, Cairo, Egypt; 5Pharmacology and Biochemistry Department, Faculty of Pharmacy, The British University in Egypt, El Shorouk, Egypt; 6Department of Food Toxicology and Contaminants, National Research Center, Cairo, EgyptCorrespondence: Shawqi H AlawdiDepartment of Pharmacology, Faculty of Medicine, Thamar University, Sana’a Street, Dhamar, YemenTel +967-777498977Email shawqialawdi@yahoo.comBackground: Diamond nanoparticles (Nanodiamond) are biocompatible drug delivery platforms with outstanding surface properties. Their passage into the brain has been confirmed previously. Thus, nanodiamond could provide a drug delivery system to shuttle several drugs through the blood-brain barrier (BBB) which represents a real challenge for the effective delivery of several drugs into the brain. Amlodipine is a calcium channel blocker that cannot pass through BBB and may elicit neuroprotective effects to reverse calcium-induced excitotoxicity and mitochondrial dysfunction that underlie several neurologic disorders including Alzheimer’s disease and stroke.Aim: The study aimed to investigate the loading of amlodipine on nanodiamond particles.Methods: Nanodiamond particles were oxidized in a strong oxidizing acidic mixture of sulfuric and nitric acids. Adsorption of amlodipine on nanodiamond particles was achieved in alkaline pH using various concentrations of sodium hydroxide. The loaded amlodipine was determined by high-performance liquid chromatography and confirmed by Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy.Results: The highest percentage (41%) of loaded amlodipine onto nanodiamond particles was achieved in alkaline medium using 2 mM NaOH at a corresponding pH of 8.5. Also, characteristic FTIR bands of amlodipine and nanodiamond were shown obviously in the nanodiamond–amlodipine conjugates. Moreover, the successful loading of amlodipine on diamond nanoparticles was confirmed by transmission electron microscopy.Conclusion: The present study demonstrates the successful loading of amlodipine onto nanodiamond particles. These findings offer a potential for applying diamond nanoparticles as a drug delivery system to shuttle amlodipine into the brain and open the door to deliver other similar drugs into the brain.Keywords: diamond nanoparticles, nanodiamond, amlodipine, calcium channel antagonists, drug delivery system, blood-brain barrier, excitotoxicity

In this work, the microstructure, mechanical properties, and corrosion behavior of the Mg-1Zn-0.6Ca matrix alloy (ZX10), reinforced by adding various amounts of nanodiamond particles (0.5, 1, and 2 wt.%), prepared by the ultrasound-assisted stir-casting method, were investigated as they are deemed as potential implant materials in biomedical applications. Microstructure, nanoindentation, mechanical tensile, immersion, and potentiodynamic polarization tests were performed for evaluating the influence of the addition of nanodiamond particles on the alloy’s mechanical and biocorrosion properties. The results revealed that the addition of nanodiamond particles causes a reduction in the alloy’s grain size. The alloy’s nanohardness and elastic modulus values increased when the amount of added nanodiamond particles were increased. The nanocomposite with an addition of 0.5% ND showed the best composition with regard to an acceptable corrosion rate as the corrosion rates are too high with higher additions of 1 or 2% NDs. At the same time, the yield strength, tensile strength, and elongation improved slightly compared to the matrix alloy.

In the present work, we have dispersed diamond nanoparticles (DNPs) in nematic liquid crystal 4-(Trans-4ʹ-n-Pentylcyclohexyl) Benzonitrile (PCH5) and studied the dielectric and optical properties of pure and DNPs dispersed nematic systems. We have investigated the effect of dispersion of DNPs (concentrations 0.5 and 1.0 wt%) in nematic liquid crystals (NLC) PCH5 on the dielectric permittivity, dielectric loss, dielectric anisotropy, photoluminescence, UV-Vis absorbance. It has been found that these properties are influenced by the dispersion of DNPs in nematic PCH5 system and applied electric field. Due to the dispersion of DNPs (1.0 wt% concentration) in PCH5, a significant decrease in the relative permittivity occurs. The relaxation peaks of dielectric loss shifts towards higher frequency side for NLC-DNPs composites. The dielectric anisotropy has been found to decrease with the dispersion of DNPs into pure NLC. The PL emission and UV-Vis absorbance for the dispersed systems have been decreased. An effort has been made to explain the observed results on the basis of interaction between nematic molecules and diamond NPs. The possible applications have also been suggested for the dispersed systems in this study. [ABSTRACT FROM AUTHOR]

The possibility of laser printing of luminescent diamond nanoparticles via a blister‐based laser‐induced forward transfer technique is demonstrated. For this purpose, a donor substrate consisting of a transparent sapphire wafer and an absorbing thin titanium film (250 and 550 nm thick) coated with nanoparticles is exposed to the radiation of an ArF excimer laser (λ = 193 nm, τ = 20 ns). Under the optimized thickness of titanium layer and laser fluence, the ejection of nanoparticles from the donor substrate is caused by the blistering of the metal film without its rupture. The luminescence mapping of the donor and acceptor substrates has proved the transfer of luminescent diamond nanoparticles with the same intensity of the signal. Features and prospects of the proposed technique are discussed. [ABSTRACT FROM AUTHOR]

Silver coatings have a very high reflection ability. To avoid their darkening from the hydrogen sulphide in the air, a thin layer of heatresistant colorless lacquer is applied to the coatings. Silver plating is mainly used in jewelery, optics, electronics and electrical engineering. Depending on their application the thickness of the layer may vary from 2 to 24 μm. It can be done in several ways: chemical, electrochemical, contact, etc. The most common way of silver plating is the electrochemical deposition using cyanide and non-cyanide electrolytes. The cyanide electrolytes produce light, fine crystalline, dense and plastic coatings upon silver-plating. Usually silver coatings are applied with copper or nickel intermediate layer. In order to improve the de-oxidation of the aluminum surface new chemical treatment in acid - alkaline solution was applied. Our previous research shows that the presence of diamond nanoparticles in the electrolyte increase the metal deposition. Samples were prepared from electrolyte containing 10 g/l diamond nanoparticles. Their properties were compared to the properties of reference samples. The diamonds were obtained by detonation synthesis. The aim of this study is to obtain electrochemically deposited silver layer with high density, adhesion and electric conductivity on aluminum alloys substrate. The coating was directly plated without intermediate layer. Non-cyanide electrolyte composition and electrochemical parameters were determined in order to produce Ag coatings on Al alloy substrate without intermediate layer. The coating is with good adhesion, density and thickness of 14-23 μm. [ABSTRACT FROM AUTHOR]

We present a flow injection system with a multiple pulse amperometric detection (FIA-MPA)-based methodology for the simultaneous analysis of sunset yellow and tartrazine. As transducer, we have developed a novel electrochemical sensor based on the synergistic effect of ReS 2 nanosheets and diamond nanoparticles (DNPs). Among several transition dichalcogenides for the sensor development, we have selected ReS 2 nanosheets since it yields a better response towards both colourants. Scanning probe microscopy characterization shows that the surface sensor is composed by scattered and stacked ReS 2 flakes and large aggregates of DNPs. With this system, the gap between the oxidation potential values of sunset yellow and tartrazine is wide enough to allow the simultaneous determination of both dyes. Under the optimum potential pulse conditions (0.8 and 1.2 V) during 250 ms, a flow rate of 3 mL/min and a volume injection of 250 μL, detection limits of 3.51 × 10−7 M and 2.39 × 10−7 M for sunset yellow and tartrazine, respectively, were obtained. This method exhibits good accuracy and precision with Er minor than 13% and RSD lower than 8% with a sampling frequency of 66 samples per hour. Pineapple jelly samples were analyzed by the standard addition method, obtaining 53.7 mg/kg and 29.0 mg/kg of sunset yellow and tartrazine, respectively. From the analysis of fortified samples, recoveries of 94% and 105% were obtained. [Display omitted] • Synergy between 2D-ReS 2 and DNPs in electrochemical sensors. • 2D-ReS 2 /DNPs platform as transducer of a FIA-MPA system. • Sunset Yellow and Tartrazine simultaneous determination in a jelly sample. [ABSTRACT FROM AUTHOR]

Vaccination remains one of the most effective tools to prevent infectious diseases. To ensure that the best possible antigenic components are chosen to stimulate a cognitive immune response, boosting antigen presentation using adjuvants is common practice. Nanodiamond-based adjuvants are proposed here as a rapid and versatile platform for antigen conjugation, utilizing peptides common to different pathogenic strains and making this strategy a good candidate for a “ready-to-use” vaccine. Initiation of an inflammatory reaction with a resulting immune response is based on the ability of living organisms to entrap nanostructures such as nanodiamonds with neutrophil extracellular traps (NETs) formation. In this work, coronavirus peptide homological for MERS-CoV, fusion inhibitor, was conjugated to nanodiamonds and used to induce neutrophilic-driven self-limiting inflammation. The resulting adjuvant was safe and did not induce any tissue damage at the site of injection. Mice immunization resulted in IgG titers of ¼,000 within 28 days. Immunization of rabbits resulted in the formation of a high level of antibodies persistently present for up to 120 days after the first immunization (animal lifespan ~3 years). The peptide used for immunization proved to be reactive with sera of convalescent COVID patients, demonstrating the possibility of developing pancoronaviral vaccine candidates.

In the present work, the dielectric properties of recycled liquid crystals (LCs) (non-purified, purified, and doped with diamond nanoparticles at 0.05, 0.1, and 0.2 wt%) were investigated. The studied LC mixtures were obtained from industrial recycling of end-of-life LC displays presenting mainly nematic phases. Dielectric measurements were carried out at room temperature on a frequency range from 0.1 to 106 Hz using an impedance analyzer. The amplitude of the oscillating voltage was fixed at 1 V using cells with homogeneous and homeotropic alignments. Results show that the dielectric anisotropy of all purified samples presents positive values and decreases after the addition of diamond nanoparticles to the LC mixtures. DC conductivity values were obtained by applying the universal law of dielectric response proposed by Jonscher. In addition, conductivity of the doped LC mixtures is lower than that of the undoped and non-purified LC.

This topical review briefly discusses selected highlights of research on diamond nanoparticles obtained by different methods and their potential applications in biology and medicine. In recent years nanotechnology has aroused interest of a large number of scientists who endeavor to obtain nanoparticles (which differ in size and structure of surface) using different methods, in order to determine their physical, chemical and biological properties that are in relation to the methods used in the process of their production. The knowledge developed in this way will be beneficial in an attempt to use nanoparticles more reasonably in various branches of science. The distinguishing features of carbon nanoparticles are their biocompatibility, photostability and easily chemically modified surface that results in high usefulness for intracellular studies. What is more, low toxicity of nanoparticles with many cell lines is at the center of scientific interest. This, in turn, leads to a large number of biomedical applications. The property that nanodiamonds are able to penetrate cells through endocytosis, allows delivering the drug connected with nanoparticles into cancer cells. These features of nanoparticles have given many promising leads in nanooncology, in particular in drug delivery, diagnosis, imaging, and therapy. This paper presents a summary of different classes of nanodiamond particles, the ways of their uptake into cells, an overview of the possible application of nanoparticles as nanocarriers and as a clinical theranostic platform, as well as advantages and disadvantages of using nanodiamonds in biomedicine. [ABSTRACT FROM AUTHOR]

Highlights • Heat transfer rate increases with the use of diamond nanolubricants. • Enhancement of the COP of the system. • Reduction of the discharge and oil sump temperatures. • Power consumption remained at the same level using nanolubricant. Abstract In this study, the experimental investigation of the use of nanolubricants based on polyol ester (POE) synthetic refrigeration oil and diamond nanoparticles at two mass concentrations, 0.1% and 0.5%, in a vapor compression refrigeration system is performed. An experimental apparatus has been developed in order to study the main parameters of a refrigeration system, such as cooling capacity, power consumption, the coefficient of performance, discharge and oil sump compressor temperatures, when diamond nanoparticles are used as a lubricant additive. The tests were performed under steady state conditions for R410A refrigerant in a scroll type compressor. The evaporation temperature and the input power frequency of the compressor were varied, while the condensation temperature was kept constant. The addition of diamond nanoparticles into the refrigeration system increased the cooling capacity and the coefficient of performance, while the discharge and the oil sump temperatures of the compressor were reduced. [ABSTRACT FROM AUTHOR]

Graphical abstract The luminescent utilities of cysteamine modified nanodiamond particles (ND-Cys) towards surface mediated energy transfer, cell imaging and metal ion recognition studies has been reported for the first time. Highlights • Low toxicity of ND-Cys has been proved by HeLa cell imaging. • Agglomeration mediated energy transfer was authenticated by Raman and PL studies. • Determination of Hg2+ was reported through PL peak shift and cell imaging. • The detection limit of Hg2+ has been estimated as 153 nM. • The Hg2+ induced graphitization was confirmed by XRD, XPS and Raman interrogations. Abstract Luminescent cysteamine-modified nanodiamond particles (ND-Cys) have been reported in surface-mediated energy transfer, cell imaging, and metal-ion recognition studies. In normalized photoluminescence (PL) spectral studies, the emission maxima of ND-Cys (at 50 µg/mL in water) was fixed at 438 nm at 350 nm excitation, producing a blue emission with a quantum yield (Φ) of 0.13. In the dispersion range of 0–800 µg/mL, ND-Cys exhibited agglomeration-induced energy transfer via red shifting of the PL peak from 438 nm to 451 nm. Analogous to PL studies, Raman interrogations also established the agglomeration and fixed the saturation limit to 500 µg/mL in water. The low toxicity and biocompatibility of ND-Cys were demonstrated using methyl thiazolyl tetrazolium assay and time-dependent HeLa cell imaging. Subsequently, the Hg2+ selectivity by ND-Cys was revealed by an intense fluorescence peak shift from 440 nm to 463 nm. Fluorescence studies indicated that the detection limit of Hg2+ ions approximated 153 nM. Fourier-transform infrared and X-ray photoelectron spectroscopy (XPS) analyses supported the binding between free thiol (SH) and amide (C O and NH) groups of ND-Cys to Hg2+. The Hg2+-induced agglomeration and surface graphitization were successfully confirmed by X-ray powder diffraction, XPS, Raman, scanning electron microscopy, transmission electron microscopy, dynamic light scattering, and zeta potential analyses. Effective detection of Hg2+ ions by ND-Cys was validated through HeLa cell imaging at shortened time intervals. [ABSTRACT FROM AUTHOR]

Diamond nanoparticles were coated onto stainless steel wires as a extraction material, then it was filled into a poly(ether ether ketone) tube for in‐tube solid‐phase microextraction. Coupled with high‐performance liquid chromatography, the extraction tube was evaluated with different types of analytes including polycyclic aromatic hydrocarbons, estrogens and plasticizers. As the coating, diamond nanoparticles exhibited greater extraction capacity for hydrophobic analytes. Several polycyclic aromatic hydrocarbons were used as model analytes, four main extraction and desorption factors were optimized, including sampling volume, sampling rate, methanol content in sample and desorption time. A sensitive analysis method was established with wide linear range (0.016–20 μg/L), good correlation coefficients (0.9991–0.9997), low limits of detection (0.005–0.020 μg/L), low limits of quantitation (0.016–0.070 μg/L) and high enrichment factors (305‐2396). Relative standard deviations for intra‐ and interday were less than 2.4% (n = 3) and 8.4% (n = 3), respectively. Durability and chemical stability were satisfactory with relative standard deviations less than 7.9% (n = 3). Finally, the method has been successfully applied to the detection of polycyclic aromatic hydrocarbons in real samples. [ABSTRACT FROM AUTHOR]

This paper reports the electrospinning fabrication of flexible nanostructured tubular scaffolds, based on fish gelatin (FG) and nanodiamond nanoparticles (NDs), and their cytocompatibility with murine neural stem cells. The effects of both nanofiller and protein concentration on the scaffold morphology, aqueous affinity, size modification at rehydration, and degradation are assessed. Our findings indicate that nanostructuring with low amounts of NDs may modify the fiber properties, including a certain regional parallel orientation of fiber segments. NE-4C cells form dense clusters that strongly adhere to the surface of FG50-based scaffolds, while also increasing FG concentration and adding NDs favor cellular infiltration into the flexible fibrous FG70_NDs nanocomposite. This research illustrates the potential of nanostructured NDs-FG fibers as scaffolds for nerve repair and regeneration. We also emphasize the importance of further understanding the effect of the nanofiller-protein interphase on the microstructure and properties of electrospun fibers and on cell-interactivity.

The viscosity and tribological behavior of nanofluids formed by dispersed nano-diamond particles within Poly-Alpha-Olefin (PAO6) lubricant is studied at different concentrations. The variation of coefficient of friction with nanoparticle concentration is measured using pin-on-disc tribometry under boundary, mixed, and hydrodynamic regimes of lubrication. A multi-scale multi-physics thermo-mixed lubrication model is developed to provide fundamental understanding of the measured tribometric results. The analytical approach combines continuum contact mechanics, thermal-mixed lubrication comprising the interaction of rough surfaces, as well as a thermal network heat transfer model. In particular, Einstein’s viscosity model for dispersed hard particles together with Vogel’s viscosity-temperature dependence model for fluid viscosity containing nanoparticles represent new contributions to knowledge. This integrated numerical-experimental study of nanofluid thermal and tribological assessment has not hitherto been reported in literature. It is shown that improved heat transfer capability of nanofluids is particularly effective in the reduction of friction under a mixed regime of lubrication.

Nanocellulose/nanocarbon composites are newly emerging smart hybrid materials containing cellulose nanoparticles, such as nanofibrils and nanocrystals, and carbon nanoparticles, such as “classical” carbon allotropes (fullerenes, graphene, nanotubes and nanodiamonds), or other carbon nanostructures (carbon nanofibers, carbon quantum dots, activated carbon and carbon black). The nanocellulose component acts as a dispersing agent and homogeneously distributes the carbon nanoparticles in an aqueous environment. Nanocellulose/nanocarbon composites can be prepared with many advantageous properties, such as high mechanical strength, flexibility, stretchability, tunable thermal and electrical conductivity, tunable optical transparency, photodynamic and photothermal activity, nanoporous character and high adsorption capacity. They are therefore promising for a wide range of industrial applications, such as energy generation, storage and conversion, water purification, food packaging, construction of fire retardants and shape memory devices. They also hold great promise for biomedical applications, such as radical scavenging, photodynamic and photothermal therapy of tumors and microbial infections, drug delivery, biosensorics, isolation of various biomolecules, electrical stimulation of damaged tissues (e.g., cardiac, neural), neural and bone tissue engineering, engineering of blood vessels and advanced wound dressing, e.g., with antimicrobial and antitumor activity. However, the potential cytotoxicity and immunogenicity of the composites and their components must also be taken into account.

The method of hot-filament chemical vapor deposition has been employed to synthesize diamond particles with germanium–vacancy and silicon–vacancy color centers. In the next stage, the reactive ion-plasma etching of the particles was performed. This, yielded diamond nanoparticles with photoluminescence spectra constituted by two narrow high-intensity zero-phonon lines of the centers introduced. These fluorescent diamond nanoparticles are promising for application as sources of double-wave narrow-band emission in luminescent nanothermometry. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • DNPs applied onto agar plate do not directly kill bacteria ( E. coli, B. subtilis, P. mirabilis ). • DNPs form clusters on agar surface that are not able to bind to cells in the colony centre. • DNPs on agar act as the mechanical barrier for the passive lateral colony growth and active cell motility. Abstract Diamond nanoparticles (DNPs) of various types have been recently reported to possess antibacterial properties. Studies have shown a decrease of the colony forming ability on agar plates of the bacteria that had been previously co-incubated with DNPs in the suspension. Before plating, bacteria with DNPs were adequately diluted in order to obtain a suitable number of colony forming units. However, residual DNPs were still present on an agar plate, concentrated on the surface during the plating process; this introduces a potential artifact which might affect colony growth. The effect of DNPs remaining on the surface, alongside growing bacteria, has not been previously investigated. In this work, we present the experiments designed to investigate the effect of DNPs on bacterial survival and on the growth of the bacterial colony on a solid media. We employed Escherichia coli and Bacillus subtilis as models of Gram-negative and Gram-positive bacteria, respectively, and Proteus mirabilis as a model of bacterium exhibiting swarming motility on the surfaces. We analyzed the number, area, and weight of bacterial colonies grown on the agar surface covered with DNPs. We did not observe any bactericidal effect of such applied DNPs. However, in all bacterial species used in this work, we observed the appreciable reduction of colony area, which suggests that DNPs obstruct either bacterial growth or motility. The most obvious effect on colony growth was observed in the case of motile P. mirabilis. We show that DNPs act as the mechanical barrier blocking the lateral colony growth. [ABSTRACT FROM AUTHOR]

In the present work, a small concentration of nano-sized (d < 10 nm) diamond particles (NSDPs) were dispersed in the ferroelectric liquid crystal (FLC) and the dielectric and optical studies such as UV absorbance and photoluminescence (PL) spectra of pure FLC as well as FLC-NPs composite were performed. The polarizing optical micrographs (POM) show aggregation of NSDPs in the FLC-NPs composite system which also affects the alignment of the FLC slightly. We have found that the dispersion of NSDPs into the FLC material strongly influences the various properties of dispersed systems. Due to NSDPs dispersion, a rapid decrease in relative permittivity, dielectric loss and ac conductivity has been observed for FLC-NPs composite at lower frequencies. The absorbance and PL emission of FLC-NPs composite has been reduced and a blue shift in PL emission was detected. The possible applications of the composite system have also been suggested in this study. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Fe nanoparticles (2–4 nm) supported on diamond have been prepared. • At 0.2 wt% loading Fe on diamond is efficient to promote the photoFenton reaction. • Turnover numbers of 38,000 have been reached for experiments at pH 4. • Fe on diamond can be reused with some minor decay in activity. • Hydroxyl radicals are the reactive oxygen species involved. Abstract Iron oxide nanoparticles (Fe ox NPs) have been supported on the hydroxylated surface of modified diamond nanoparticles (D3). Characterization data show that, once formed, Fe NPs are spontaneously oxidized under ambient conditions, exhibiting a good dispersion of small oxidized Fe ox NPs (2.2 ± 0.5 nm) on D3. It has been observed that the activity of Fe ox /D3 as heterogeneous Fenton catalyst for phenol degradation by H 2 O 2 can be assisted by visible light irradiation. Fe ox /D3 exhibits a superior activity compared with analogous catalysts based on activated carbon, graphite or the benchmark Fe ox /TiO 2 photocatalyst. Fe ox /D3 exhibits comparable activity to Ag/D3 that is one of the most active catalysts ever reported for this reaction. In addition, Fe ox /D3 presents higher stability and recyclability than analogous Cu/D3. A minimum accumulated turnover number of 38,000 can be achieved using Fe ox /D3 as photocatalyst. The heterogeneous photoFenton process using phenol as model pollutant and Fe ox /D3 as catalyst under visible light irradiation can be implemented prior to an aerobic biological treatment resulting in a biodegradable effluent which lacks ecotoxicity, as determined by measurement of the biological oxygen demand. Transient absorption spectroscopy provides evidence in support of the formation upon irradiation of Fe ox /D3 of photogenerated charge separation state attributed to electrons and holes. Electron paramagnetic resonance and selective quenching experiments indicate that hydroxyl radicals are the main reactive oxygen species generated in the photo-assisted Fenton reaction promoted by Fe ox /D3. [ABSTRACT FROM AUTHOR]

Diamond nanoparticles (DNPs) have been strongly integrated into diverse technological applications due to its nano-size, good chemical stability, super hardness, thermal conductivity and biocompatibility. Agglomeration and non-uniform distribution of DNPs in different matrices are the two main concern problems which limits its wide spread applications. Herein, our present research work demonstrated a comparative study of ball milling and acid treatments of functionalization DNPs through surface modification with carboxylic acid and amid functional groups. The dispersion measurement showed that ball mill treated DNPs is uniform and homogeneously dispersed in dimethyl-sulfoxide (DMSO) rather than as-received and acid treated DNPs. Furthermore, the use of various weight percentages of acid and ball mill functionalized DNPs in epoxy resin showed that 0.2 wt% is the optimum amount which revealed the highest ultimate tensile strength, flexural strength, Young's modulus and energy to break values of the nanocomposites. The comparative analysis showed that ball mill treatment of functionalization significantly enhanced the mechanical performances of epoxy resin more effectively than acid treatment thus demonstrated the importance of ball milling technique. [ABSTRACT FROM AUTHOR]

Abstract: N‐hydroxyphthalimide (NHPI) derived from trimellitic anhydride has been covalently anchored (4 wt %) through ester bonds to the surface of commercial diamond nanoparticles previously functionalized by chemical and thermal treatments (DH). IR spectroscopy of the NHPI/DH solid shows the presence of a characteristic peak at 1735 cm−1 attributable to the ester bond, while solid‐state MAS 13C NMR spectroscopy shows two broad bands corresponding to carbon atoms of carbonyl groups (167 ppm) and aromatic carbons (127 ppm). NHPI/DH promotes autoxidation of isobutylbenzene involving superoxide (O2.−) and hydroperoxide (HOO⋅) radicals; NHPI/DH can be reused at least three times and reach a minimum turnover number as high as 20 600, which is probably due to the inertness of the diamond surface, allowing free diffusion of reactive oxygen species. Analogous materials in which NHPI was anchored on activated carbon and multiwall carbon nanotubes were inefficient as autoxidation catalysts. NHPI/DH is able to promote also selective aerobic oxidation of other benzylic hydrocarbons and cycloalkenes. [ABSTRACT FROM AUTHOR]

Abstract: N‐hydroxyphthalimide (NHPI) derived from trimellitic anhydride has been covalently anchored (4 wt %) through ester bonds to the surface of commercial diamond nanoparticles previously functionalized by chemical and thermal treatments (DH). IR spectroscopy of the NHPI/DH solid shows the presence of a characteristic peak at 1735 cm−1 attributable to the ester bond, while solid‐state MAS 13C NMR spectroscopy shows two broad bands corresponding to carbon atoms of carbonyl groups (167 ppm) and aromatic carbons (127 ppm). NHPI/DH promotes autoxidation of isobutylbenzene involving superoxide (O2.−) and hydroperoxide (HOO⋅) radicals; NHPI/DH can be reused at least three times and reach a minimum turnover number as high as 20 600, which is probably due to the inertness of the diamond surface, allowing free diffusion of reactive oxygen species. Analogous materials in which NHPI was anchored on activated carbon and multiwall carbon nanotubes were inefficient as autoxidation catalysts. NHPI/DH is able to promote also selective aerobic oxidation of other benzylic hydrocarbons and cycloalkenes. [ABSTRACT FROM AUTHOR]