Nanoscale Advances最新文献

{"title":"Laser surface nanoalloying of Fe, Si, and C on aluminum substrates with excellent optical and electronic properties.","authors":"Asad A Thahe, Motahher A Qaeed, Nahla Hilal, Dauda Abubakar, Noriah Bidin, Nageh K Allam","doi":"10.1039/d4na01023j","DOIUrl":"https://doi.org/10.1039/d4na01023j","url":null,"abstract":"<p><p>Laser surface alloying of Fe, Si, and C on aluminium is demonstrated using a Q-switched Nd:YAG laser as the source of energy. The fundamental wavelength of the laser beam was 1064 nm with an output energy of 100 mJ and a pulse duration of 10 ns. The exposure was conducted in repetitive mode with a frequency rate of 1 Hz. The laser was focused to induce plasma formation. A pure aluminium plate was employed as the substrate to be alloyed. Iron (Fe) and ceramic material silicon carbide SiC were selected as the alloy elements. Two step deposition techniques were employed to predeposit the aluminium substrate. The substrate was painted with a cohesive material gum before powder spray coating on it. The predeposited aluminium was then exposed to a focused laser at various numbers of pulses (1-13 pulses). The resulting materials were examined <i>via</i> scanning electron microscopy (SEM), X-ray diffraction (XRD), and microhardness techniques, revealing the formation of a homogenized resolidified surface. The plasma temperature was much higher than the melting point of Fe and SiC, enabling an immediate interaction with coating materials. The different melting points of Fe, SiC, and Al allowed the formation of a new composite during quenching. The formation of such a new composite is identified <i>via</i> XRD analysis. Inherently, several new composites were revealed, such as Al-Fe-Si, SiAl, and Fe-Si, with enhanced mechanical strength. Apparently, the hardness of the modified surface is confirmed to be two times greater than that of the original substrate. The sensitivity of the MSM photodetector (PD) made of the resulting alloy is reasonably high and increases with increasing the bias voltage. The response times (<i>T</i> _Res) of the MSM PD for various numbers of laser pulses (1-13 pulses) were 0.60 s, 0.28 s, and 0.67 s with corresponding recovery times (<i>T</i> _Rec) of 0.53 s, 0.21 s, and 1.81 s, respectively.</p>","PeriodicalId":18806,"journal":{"name":"Nanoscale Advances","volume":" ","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11775984/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143066786","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sulfur isotope engineering in heterostructures of transition metal dichalcogenides†","authors":"Vaibhav Varade, Golam Haider, Martin Kalbac and Jana Vejpravova","doi":"10.1039/D4NA00897A","DOIUrl":"10.1039/D4NA00897A","url":null,"abstract":"<p >Heterostructuring of two-dimensional materials offers a robust platform to precisely tune optoelectronic properties through interlayer interactions. Here we achieved a strong interlayer coupling in a double-layered heterostructure of sulfur isotope-modified adjacent MoS<small>₂</small> monolayers <em>via</em> two-step chemical vapor deposition growth. The strong interlayer coupling in the MoS<small>₂</small>(<small>³⁴</small>S)/MoS<small>₂</small>(<small>³²</small>S) was affirmed by low-frequency shear and breathing modes in the Raman spectra. The photoluminescence emission spectra showed that isotope-induced changes in the electronic structure and strong interlayer coupling led to the suppression of intralayer excitons, resulting in dominant emission from the MoS<small>₂</small>(<small>³²</small>S) layer. Time-resolved photoluminescence experiments indicated faster lifetimes in the MoS<small>₂</small>(<small>³⁴</small>S)/MoS<small>₂</small>(<small>³²</small>S) heterostructure compared to the conventional bilayers with the natural isotopic abundance, highlighting nuanced interlayer exciton dynamics due to the isotopic modification. This study underscores the great potential of isotope engineering in van der Waals heterostructures, as it enables tailoring the band structure and exciton dynamics at the nuclear level without the need of chemical modification.</p>","PeriodicalId":18806,"journal":{"name":"Nanoscale Advances","volume":" 5","pages":" 1276-1286"},"PeriodicalIF":4.6,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11748049/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143024062","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A biocompatible β-cyclodextrin inclusion complex containing natural extracts: a promising antibiofilm agent†","authors":"Obaydah Abd Alkader Alabrahim, Mostafa Fytory, Ahmed M. Abou-Shanab, Jude Lababidi, Wolfgang Fritzsche, Nagwa El-Badri and Hassan Mohamed El-Said Azzazy","doi":"10.1039/D4NA00916A","DOIUrl":"10.1039/D4NA00916A","url":null,"abstract":"<p >Biofilms formed by several bacterial strains still pose a significant challenge to healthcare due to their resistance to conventional treatment approaches, including antibiotics. This study explores the potential of loading natural extracts with antimicrobial activities into β-cyclodextrin (βCD) nanoparticles, which are FDA-approved and have superior biocompatibility owing to their cyclic sugar structures, for biofilm eradication. An inclusion complex of βCD carrying <em>Boswellia sacra</em> essential oils (BOS) was prepared and characterized with regard to its physicochemical properties, antimicrobial efficacy, and antibiofilm activities. Encapsulation of BOS into βCD significantly enhanced the antimicrobial activity of BOS by 4-fold against Gram-positive (<em>Staphylococcus aureus</em> and <em>Bacillus subtilis</em>) and by 8-fold against Gram-negative (<em>Escherichia coli</em> and <em>Pseudomonas putida</em>) bacteria, with minimum inhibitory concentrations ranging from 2.5 to 5 mg mL<small>⁻¹</small>. Furthermore, the BOS-βCD complex demonstrated a dual-action against bacterial biofilms where it prevented biofilm formation and disrupted established biofilms. This resulted in a significant reduction in biofilm biomass, with prevention and disruption rates reaching up to 93.78% and 82.17%, respectively. Additionally, the formula revealed an excellent biocompatibility profile with no induction of oxidative stress in human skin fibroblast cells. Our findings suggest that βCD nanoparticles loaded with BOS essential oils hold promise as an effective formula for preventing the formation of bacterial biofilms and combating preformed ones for use in relevant medical applications.</p>","PeriodicalId":18806,"journal":{"name":"Nanoscale Advances","volume":" 5","pages":" 1405-1420"},"PeriodicalIF":4.6,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11748956/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143024056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optimal size and PEG coating of gold nanoparticles for prolonged blood circulation: a statistical analysis of published data†","authors":"Dmitry Nevozhay, Ronald Rauch, Zhongya Wang and Konstantin V. Sokolov","doi":"10.1039/D4NA00782D","DOIUrl":"10.1039/D4NA00782D","url":null,"abstract":"<p >This study presents a statistical analysis of how gold nanoparticle (GNP) size and polyethylene glycol (PEG) coating molecular weight (MW) affect the circulation of nanoparticles in blood. We showed a non-linear relationship with interaction between GNP size and PEG MW. The findings revealed a threshold effect, and recommendations for GNP coating are discussed.</p>","PeriodicalId":18806,"journal":{"name":"Nanoscale Advances","volume":" 3","pages":" 722-727"},"PeriodicalIF":4.6,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11726233/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142984209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revolutionizing green catalysis: a novel amla seed derived biochar modified g-C₃N₄·SO₃H catalyst for sustainable and versatile synthesis of bis-indoles.","authors":"Shivani Soni, Sunita Teli, Pankaj Teli, Shikha Agarwal","doi":"10.1039/d4na00891j","DOIUrl":"https://doi.org/10.1039/d4na00891j","url":null,"abstract":"<p><p>Catalysis plays a vital role in green chemistry by improving process efficiency, reducing waste, and minimizing environmental impact. A biochar-modified g-C₃N₄·SO₃H (BCNSA) catalyst was developed using biochar derived from amla seed powder and CNSA. CNSA was synthesized <i>via</i> the reaction of g-C₃N₄ with chlorosulfonic acid. Both components were combined, pyrolyzed, purified, and comprehensively characterized using FTIR, XRD, FE-SEM, EDX, elemental mapping, TGA, and DTA studies to confirm the successful synthesis and structural integrity. The catalyst demonstrated exceptional efficiency in synthesizing bis-indole derivatives through reactions between substituted indoles (indole, 1-methyl indole, and 6-chloro indole) and carbonyl-containing compounds, including isatins (isatin, 7-(trifluoromethyl)isatin, 5-bromo isatin, and 5-fluoro isatin), aldehydes, cyclo-ketones, dimedone, and acetophenones. These reactions were carried out under simplified conditions using water as a green solvent, promoting sustainability and versatility. A total of 21 bis-indole products were synthesized within 5-45 minutes, achieving yields of 80-98% showcasing the catalyst's outstanding performance. Furthermore, the method was scaled up to gram-level synthesis, and green chemistry metrics were evaluated for all the products, highlighting the environmental and economic benefits of this approach.</p>","PeriodicalId":18806,"journal":{"name":"Nanoscale Advances","volume":" ","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11774277/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143066050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Engineering Au single-atom sites embedded in TiO₂ nanostructures for boosting photocatalytic methane oxidation.","authors":"Qui Thanh Hoai Ta, Ly Tan Nhiem","doi":"10.1039/d4na00947a","DOIUrl":"10.1039/d4na00947a","url":null,"abstract":"<p><p>Photocatalytic methane oxidation under mild conditions using single-atom catalysts remains an advanced technology. In this work, gold single atoms (Au SAs) were introduced onto TiO₂ nanostructures using a simple method. The resulting performance demonstrated effective conversion of methane into H₂ and C₂ products at room temperature. The as-synthesized Au SA/TiO₂ exhibited a high hydrogen production rate of 2190 μmol g^-1, with selectivity reaching up to 58% under optimized conditions. The methane oxidation mechanism was investigated, revealing a methyl radical pathway for generating value-added chemicals. This research provides a strategy for photocatalytic methane conversion over single-atom-supported photocatalysts.</p>","PeriodicalId":18806,"journal":{"name":"Nanoscale Advances","volume":" ","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11770591/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143059629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pyrroloquinoline quinone-loaded coaxial nanofibers prevent oxidative stress after spinal cord injury.","authors":"Sara Ibrahim, Mohammed Ismail, Taghrid Abdelrahman, Mona Sharkawy, Ahmed Abdellatif, Nageh K Allam","doi":"10.1039/d4na00885e","DOIUrl":"10.1039/d4na00885e","url":null,"abstract":"<p><p>Oxidative stress plays a major role in the secondary injury of the spinal cord tissue due to the high lipid content of nervous tissue. In the present study, coaxial nanofibers were loaded with the natural antioxidant pyrroloquinoline quinone (PQQ) and used as an implantable drug-delivery system and a scaffold post-SCI. The obtained data show that the concentration of NO and the activity of inducible nitric oxide synthase (iNOS) were significantly (<i>P</i> < 0.05) increased in the spinal cord injury (SCI) group. These levels were significantly decreased following treatment with nanofibers/PQQ. Implantation of nanofibers/PQQ resulted in a significant (<i>P</i> < 0.05) drop in the level of malondialdehyde (MDA) compared to the SCI group. The application of nanofibers loaded with PQQ after SCI caused a significant (<i>P</i> < 0.05) elevation of superoxide dismutase (SOD) and catalase (CAT) activity in the spinal cord tissue. The present work shows the protective role of coaxial nanofibers loaded with PQQ against oxidative stress in spinal cord injury. The reversal of oxidative stress with PQQ can lead to better outcomes following spinal cord injury.</p>","PeriodicalId":18806,"journal":{"name":"Nanoscale Advances","volume":" ","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11770590/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143059643","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the structure-property correlations of pyrolyzed phenolic resin as a function of degree of carbonization.","authors":"Ivan Gallegos, Vikas Varshney, Josh Kemppainen, Gregory M Odegard","doi":"10.1039/d4na00824c","DOIUrl":"10.1039/d4na00824c","url":null,"abstract":"<p><p>Carbon-carbon (C/C) composites are attractive materials for high-speed flights and terrestrial atmospheric reentry applications due to their insulating thermal properties, thermal resistance, and high strength-to-weight ratio. It is important to understand the evolving structure-property correlations in these materials during pyrolysis, but the extreme laboratory conditions required to produce C/C composites make it difficult to quantify the properties <i>in situ</i>. This work presents an atomistic modeling methodology to pyrolyze a crosslinked phenolic resin network and track the evolving thermomechanical properties of the skeletal matrix during simulated pyrolysis. First, the crosslinked resin is pyrolyzed and the resulting char yield and mass density are verified to match experimental values, establishing the model's powerful predictive capabilities. Young's modulus, yield stress, Poisson's ratio, and thermal conductivity are calculated for the polymerized structure, intermediate pyrolyzed structures, and fully pyrolyzed structure to reveal structure-property correlations, and the evolution of properties are linked to observed structural features. It is determined that reduction in fractional free volume and densification of the resin during pyrolysis contribute significantly to the increase in thermomechanical properties of the skeletal phenolic matrix. A complex interplay of the formation of six-membered carbon rings at the expense of five and seven-membered carbon rings is revealed to affect thermal conductivity. Increased anisotropy was observed in the latter stages of pyrolysis due to the development of aligned aromatic structures. Experimentally validated predictive atomistic models are a key first step to multiscale process modeling of C/C composites to optimize next-generation materials.</p>","PeriodicalId":18806,"journal":{"name":"Nanoscale Advances","volume":" ","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11770810/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143059632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selective modal excitation in a multimode nanoslit by interference of surface plasmon waves","authors":"Marcos Valero, Luis-Angel Mayoral-Astorga, Howard Northfield, Hyung Woo Choi, Israel De Leon, Mallar Ray and Pierre Berini","doi":"10.1039/D4NA00862F","DOIUrl":"10.1039/D4NA00862F","url":null,"abstract":"<p >Interference of surface plasmons has been widely utilized in optical metrology for applications such as high-precision sensing. In this paper, we introduce a surface plasmon interferometer with the potential to be arranged in arrays for parallel multiplexing applications. The interferometer features two grating couplers that excite surface plasmon polariton (SPP) waves traveling along a gold–air interface before converging at a gold nanoslit where they interfere. A key innovation lies in the ability to tune the interference pattern by altering the geometrical properties of the gold nanoslit such that one, two or more resonance modes are supported in the nanoslit. Our experimental results validate the approach of our design and modelling process, demonstrating the potential to fine-tune geometrical parameters such as grating coupler pitch, depth, duty cycle, and nanoslit dimensions to alter the transmitted radiation pattern and the transmittance. We demonstrate the ability of a grating coupler to induce focusing of SPP waves to an arbitrary location on chip by illuminating with a converging Gaussian beam. Additionally, we observed far-field interference patterns linked to the multimodal operation of the nanoslit.</p>","PeriodicalId":18806,"journal":{"name":"Nanoscale Advances","volume":" 5","pages":" 1305-1317"},"PeriodicalIF":4.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11718371/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142971655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microwave-assisted synthesis of highly photoluminescent core/shell CuInZnSe/ZnS quantum dots as photovoltaic absorbers†","authors":"Shubham Shishodia, Hervé Rinnert, Lavinia Balan, Jordane Jasniewski, Stéphanie Bruyère, Ghouti Medjahdi, Thomas Gries and Raphaël Schneider","doi":"10.1039/D4NA00893F","DOIUrl":"10.1039/D4NA00893F","url":null,"abstract":"<p >Water-dispersible core/shell CuInZnSe/ZnS (CIZSe/ZnS) quantum dots (QDs) were efficiently synthesized under microwave irradiation using <em>N</em>-acetylcysteine (NAC) and sodium citrate as capping agents. The photoluminescence (PL) emission of CIZSe/ZnS QDs can be tuned from 593 to 733 nm with varying the Zn : Cu molar ratio in the CIZSe core. CIZSe/ZnS QDs prepared with a Zn : Cu ratio of 0.5 exhibit the highest PL quantum yield (54%) and the longest PL lifetime (515 ns) originating from the recombination of donor–acceptor pairs. The potential of CIZSe/ZnS QDs as photoabsorbers in QD-sensitized solar cells was also evaluated. An adequate type-II band alignment is observed between TiO<small>₂</small> and CIZSe/ZnS QDs, indicating that photogenerated electrons in CIZSe/ZnS QDs could efficiently be injected into TiO<small>₂</small>.</p>","PeriodicalId":18806,"journal":{"name":"Nanoscale Advances","volume":" 5","pages":" 1326-1334"},"PeriodicalIF":4.6,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11731178/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143008664","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}