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We introduce a unique soft lithographic operation that exploits stamp roof collapse-induced gaps to selectively remove an alkanethiol self-assembled monolayer (SAM) on Au to generate surface patterns that are orders of magnitude smaller than structures on the original elastomer stamp. The smallest achieved feature dimension is 5 nm using a micrometer-scale structured stamp in a chemical lift-off lithography (CLL) process. Molecular patterns retained in the gaps between stamp features and their circumscribed or inscribed circles follow mathematical predictions, and their sizes can be tuned by altering the stamp structure dimensions, including height, pitch, and shape. These generated surface molecular patterns can function as biorecognition arrays or be transferred to the underneath Au layer for metallic structure creation. By combining CLL process with this gap phenomenon, soft material properties that are previously thought as demerits can be used to achieve sub-10 nm features in a straightforward sketch.

Nowadays, phosphors are widely used in high quality white light emitting diodes (W‐LEDs) and display technology. Micro light emitting diode (Micro‐LED) has the advantages of ultrahigh resolution color saturation, while ordinary phosphors are difficult to apply due to their large particle size. As is known to all, once the phosphor particle size is reduced, its luminescence intensity will loser. This paper presents a strategy to improve the luminescence intensity of sub‐micrometer narrow‐band red phosphors. By increasing the doping concentration of rare‐earth ions through total substitution and reducing the nonradiative transition in the cell, ultrahigh concentration doping of sub‐micrometer phosphors is achieved to improve the luminescence intensity. Surprisingly, with increasing Eu3+ up to entirely substitution for Gd3+ site, both the absorption efficiency and the internal quantum efficiency of the sample increased greatly. The external quantum efficiency increased from 5.42% to 19.70%. Sub‐micrometer EuAl3(BO3)4 exhibits ultrahigh thermal stability, with a luminous intensity at 225 °C that is 128% of that at room temperature, meeting the conditions of extreme high‐temperature environments or high‐power LEDs. In summary, this work has great potential for application in W‐LED and presents a solution idea to solve the luminous intensity reduction of sub‐micrometer phosphors. [ABSTRACT FROM AUTHOR]

Regardless of the technology, additive or subtractive, the miniaturization trend is constantly pushing for smaller resolutions. The rise of global challenges in material availability, fabrication in three dimensions (3D), design flexibility and rapid prototyping have pushed additive manufacturing (AM) into the spotlight. Addressing the miniaturization trend, AM has already successfully answered the challenges for microscale 3D fabrication. However, fabricating nano-resolution still presents a challenge. In this review, we will present some of the most reported AM-based technologies capable of nanoscale 3D fabrication addressing resolutions of ≤ 500 nm. The focus is placed on Electrohydrodynamic (EHD) printing (also known as e-jet printing), as EHD printing seems to have the best trade-off when it comes to technique complexity, achievable resolutions, material diversity and potential to scale-up throughput. An overview of the smallest achieved resolutions as well as the most unique use cases and demonstrated applications will be addressed in this work.

Nanostructured manganese sulfide (MnS) has been verified to be effective to address the issues of MnS as next‐generation anode material in high energy lithium‐ion batteries (LIBs). The scale‐up fabrication, however, is still challenged by the multistep and rigid processes of synthesizing MnS nanoparticles. Herein, by using micro‐sized MnS as low‐cost MnS source, we present a facile, cost‐effective and scalable strategy to prepare a sub‐micrometer sized MnS@NSC composite, in which MnS nanoparticles are encapsulated into N,S‐codoped carbon matrix (NSC) deriving from polyacrylonitrile (PAN). The NSC matrix combined with homogeneously distributed MnS nanoparticles crushed from micro‐MnS provide fast access of lithium ion/electron and robust structure, leading to remarkable cycling stability (551.6 mAh g−1 at 0.5 A g−1 even after 400 cycles) and desirable rate capability (624 mAh g−1 at 0.1 A g−1 and around 300 mAh g−1 at 2 A g−1). Particularly, the assembled LIB full cell by coupling the anode with LiFePO4 (LFP) cathode presents an encouragingly cycling retention of 96 % after 100 cycles. This work provides a new possibility for design and industrial implementation of MnS as advanced anode materials for LIBs. [ABSTRACT FROM AUTHOR]

Laser direct structuring using multi-beam interference can fabricate one and two-dimensional periodic patterns with a structural periodicity from hundred nanometer to tens of micrometer. Nevertheless, the structuring efficiency, which is relative to patterning speed, structure periodicity, depth and laser fluence applied, and homogeneity of interference pattern are still the main concerns and need to be taken into consideration especially for large-scale surface. In this paper, the structuring efficiency of two beam interference was defined and was investigated on tool steel using an ultrashort pulsed (USP) laser. During the multi-beam interference structuring, the USP laser, which has a pulse width of 10 picoseconds, worked at a wavelength of 532 nm and repetition rate of 100 kHz. Linear patterns with a periodicity of 940 nm and was fabricated on an area of 100 mm × 100 mm. We achieved a patterning speed up to 500 mm/s on the surface of tool steel by means of an x-y linear working stage. The local morphology was analyzed by an atom force microscopy (AFM). Moreover, the global homogeneity of the patterned surface was quantitatively characterized. The results demonstrated a stable structuring process with minor deviation of structure periodicity and depth. [ABSTRACT FROM AUTHOR]

We introduce a unique soft lithographic operation that exploits stamp roof collapse-induced gaps to selectively remove an alkanethiol self-assembled monolayer (SAM) on Au to generate surface patterns that are orders of magnitude smaller than structures on the original elastomer stamp. The smallest achieved feature dimension is 5 nm using a micrometer-scale structured stamp in a chemical lift-off lithography (CLL) process. Molecular patterns retained in the gaps between stamp features and their circumscribed or inscribed circles follow mathematical predictions, and their sizes can be tuned by altering the stamp structure dimensions, including height, pitch, and shape. These generated surface molecular patterns can function as biorecognition arrays or be transferred to the underneath Au layer for metallic structure creation. By combining CLL process with this gap phenomenon, soft material properties that are previously thought as demerits can be used to achieve sub-10 nm features in a straightforward sketch., (Copyright © 2023, Wang et al.)

Cu particles ranging in size from several micrometers to less than a micrometer were synthesized using an environmentally friendly hydrothermal process involving L-ascorbic acid as a reducing agent and gelatin. The size and synthetic yield of Cu particles was investigated at different gelatin additions and synthesis temperatures. With increasing gelatin content, the particle size decreased from 2.4 µm to 0.4 µm and the yield increased from 79.4% to 90.4%. With increasing synthesis temperature, the particle size changed significantly and the yield increased from 42.4% to 91.2%. The Cu particles synthesized at 85°C for 50 min with 12 g of gelatin showed the lowest average particle size of 0.4 µm and a yield of 90.4%. The FR-IR spectra indicated that coordinating bonds between the N in the gelatin and the Cu were formed, and a sequential reaction mechanism was proposed. It was determined that the gelatin addition not only prevents the Cu particles from agglomerating but also enhances the reduction of Cu ions.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

In fatigue, micrometer and sub-micrometer metal components do not have sufficient space to form persistent slip band (PSB) structures, which bring about the extrusions/intrusions with the size of a few micrometers in bulk metal. The characteristic feature of fatigue behavior at this scale is investigated using resonance vibration fatigue experiments on single crystal gold cantilevers of various sizes. Fatigue damage of extrusion/intrusion is formed on the cantilever surface in all specimens. The width of the extrusion/intrusion decreases with the size of cantilever, from hundreds to tens nanometers, which is much smaller than that in bulk components. And the slip traces formation is spatially periodic. The resolved shear stress to form an extrusion/intrusion is strongly dependent on the specimen size and is much higher than that in the bulk. [ABSTRACT FROM AUTHOR]

Highlights: [•] We investigated long-term insulation performance of sub-μm parylene C coatings. [•] Electrochemical impedance spectroscopy was measured at 90°C for 45 days. [•] Degraded insulation was observed due to water diffusion followed by delamination. [•] 500nm coating showed stable electrical characteristics during the test period. [ABSTRACT FROM AUTHOR]

Highlights: [•] Photoanodes with sub-micrometer cavities of various sizes and ratios were fabricated. [•] Polystyrene sub-micrometer spheres embedded in TiO2 paste were burn off. [•] Remarkably, 48% enhancement was observed in conversion efficiency. [ABSTRACT FROM AUTHOR]

Abstract: This paper focuses on deep reactive ion etching (DRIE) of sub-micrometer features. Very high aspect ratios up to 160:1 on trenches of 250nm have been achieved using the Bosch process and up to 120:1 on trenches of 35nm using a cryogenic process. The proposed etch recipes are specifically optimized for sub-micrometer features, and are not compatible with feature sizes in the tens of micrometer range. Based on analyzing data from our experiments and from literature, we show that a previously reported two-parameter empirical logarithmic law accurately describes the dependency of aspect ratio on trench width over a wide range of widths and etch parameters, including the sub-micrometer regime. We also propose a new figure of merit (FOM) that describes the ultimate aspect ratio achievable for any given etching process. This FOM also allows comparison of different aspect ratio performances, while taking into account in the same time, the dimension of the trench for which this performance is attained. [Copyright &y& Elsevier]

Abstract: When treating water with activated carbon, natural organic matter (NOM) is not only a target for adsorptive removal but also an inhibitory substance that reduces the removal efficiency of trace compounds, such as 2-methylisoborneol (MIB), through adsorption competition. Recently, superfine (submicron-sized) activated carbon (SPAC) was developed by wet-milling commercially available powdered activated carbon (PAC) to a smaller particle size. It was reported that SPAC has a larger NOM adsorption capacity than PAC because NOM mainly adsorbs close to the external adsorbent particle surface (shell adsorption mechanism). Thus, SPAC with its larger specific external surface area can adsorb more NOM than PAC. The effect of higher NOM uptake on the adsorptive removal of MIB has, however, not been investigated. Results of this study show that adsorption competition between NOM and MIB did not increase when NOM uptake increased due to carbon size reduction; i.e., the increased NOM uptake by SPAC did not result in a decrease in MIB adsorption capacity beyond that obtained as a result of NOM adsorption by PAC. A simple estimation method for determining the adsorbed amount of competing NOM (NOM that reduces MIB adsorption) is presented based on the simplified equivalent background compound (EBC) method. Furthermore, the mechanism of adsorption competition is discussed based on results obtained with the simplified EBC method and the shell adsorption mechanism. Competing NOM, which likely comprises a small portion of NOM, adsorbs in internal pores of activated carbon particles as MIB does, thereby reducing the MIB adsorption capacity to a similar extent regardless of adsorbent particle size. SPAC application can be advantageous because enhanced NOM removal does not translate into less effective removal of MIB. Molecular size distribution data of NOM suggest that the competing NOM has a molecular weight similar to that of the target compound. [Copyright &y& Elsevier]

In this study, sub-micrometer LiFePO particles with high purity and crystallinity were synthesized using supercritical hydrothermal method as the cathode material for lithium ion batteries. Experimental results show that templates and calcination time have significant impacts on the purity, particle size and morphology of LiFePO particles. The as-prepared LiFePO particles using polyvinyl pyrrolidone (PVP) template with additional one hour calcination at 700°C exhibit characteristics of good crystallinity, uniform size distribution, high capacity and cycling performance. The specific discharge capacities of 141.2 and 114.0mA·h/g were obtained at the charge/discharge rates of 0.1 and 1.0 C, respectively. It retained 96.0% of an initial capacity after 100 cycles at 1.0 C rate. The good electrochemical performance of the as-synthesized material is attributed to the synergistic factors of its reasonable particle size and surface areas and high crystallinity. [ABSTRACT FROM AUTHOR]

Abstract: Slides for ultra thin-layer chromatography (UTLC) were made by coating nonporous silica particles, chemically modified with polyacrylamide, as 15μm films on glass or silicon. Three proteins, myoglobin, cytochrome c and lysozyme, are nearly baseline resolved by the mechanism of hydrophilic interaction chromatography. A plate height as low as 3μm, with 3900 plates, is observed in 14mm. Varying silica particle diameter among 900, 700 and 350nm showed that decreasing particle diameter slightly improves resolution but slows the separation. Matrix-assisted laser desorption/ionization (MALDI)-MS of the proteins after separation is demonstrated by wicking sufficient sinapinic acid into the separation medium. [Copyright &y& Elsevier]

Abstract: Information on plutonium isotope ratios in individual particles is of great importance for nuclear safeguards, nuclear forensics and so on. Although secondary ion mass spectrometry (SIMS) is successfully utilized for the analysis of individual uranium particles, the isobaric interference of americium-241 to plutonium-241 makes difficult to obtain accurate isotope ratios in individual plutonium particles. In the present work, an analytical technique by a combination of chemical separation and inductively coupled plasma mass spectrometry (ICP-MS) is developed and applied to isotope ratio analysis of individual sub-micrometer plutonium particles. The ICP-MS results for individual plutonium particles prepared from a standard reference material (NBL SRM-947) indicate that the use of a desolvation system for sample introduction improves the precision of isotope ratios. In addition, the accuracy of the 241Pu/239Pu isotope ratio is much improved, owing to the chemical separation of plutonium and americium. In conclusion, the performance of the proposed ICP-MS technique is sufficient for the analysis of individual plutonium particles. [ABSTRACT FROM AUTHOR]

Abstract: We report on mobilities up to 3.6cm2/Vs in organic field-effect transistors (OFETs) with solution-processed dithiophene- and dibenzo-tetrathiafulvalene (DT- and DB-TTF) single crystals as active materials. In the devices, the channel length varies from 100μm down to sub 100nm, and the SiO2 thickness is either 100nm, 50nm, or 20nm. The devices exhibit excellent operation characteristics with an on/off-ratio exceeding 106. Temperature dependent measurements between 50 and 400K reveal a thermally activated transport with increased activation above 200K. The mobility exhibits exponential activation with two distinct exponents. [Copyright &y& Elsevier]

As road networks become increasingly more congested, environmental concerns relating to emissions from motor vehicles assume a higher significance. This study found that road side concentrations of particles produced by freeway traffic in Brisbane, Australia, is primarily dependent upon traffic flow differentiated into fuel type, and wind speed. The analysis differentiates between diesel and petrol vehicles, and finds that particle concentration is very sensitive to the proportion of diesel-fuelled vehicles. A 20% increase in diesel vehicles can produce an 18% increase in particle concentrations compared with a 2% particle increase for the same number of additional petrol vehicles. [Copyright &y& Elsevier]

• Combustion of JP-10 droplet laden with sub-micron boron particles is studied. • Commercially boron particles generally have inconsistent size/morphology. • Particle burning is characterized in terms of flame images and emission spectra. • Effect of puffing/micro-explosion on primary and secondary flames is analyzed. • Analyzed the Combustion residue in terms of morphology to correlate droplet burning. The present study deals with the droplet combustion characteristics of JP-10 fuel droplets containing three commercially available boron particles at 10% loading (by weight). Characterization of feed boron particles regarding particle size, morphology, ignition temperature, and oxidation profile have been conducted using conventional material characterization techniques such as scanning electron microscope (SEM), X-ray diffraction (XRD), particle size analyzer and thermogravimetric analysis (TGA). Ignition and combustion characteristics of all the boron samples loaded in JP-10 at desired concentration have been analyzed to understand the burning behaviour of these boron samples in JP-10 fuel. The droplet diameter evolution profiles show distinctly different characteristics for Loba Chemie (BL), Sigma-Aldrich (BS) and Telmat Materials (BT) boron loaded droplets. For BL loaded JP-10 fuel sample, the droplet regresses smoothly till the mid-span of the burning process. Some strong fluctuations in droplet diameter were also observed during the process. Similarly, for BS laden JP-10 fuel droplet, the regression started smoothly with some catastrophic fragmentation which eventually prevailed and led to the disruption of the primary droplet. In contrast, the regression curve of BT laden JP-10 fuel droplet is fluctuating in nature which leads to the occurrence of multiple micro-explosion. SEM images of combustion residue show multiple blow holes on particle surface in case of BS laden JP-10 fuel droplet whereas there are no such blow holes present in the residue for BL loaded case. From the residue micrographs, the particles seem to be well separated for BS case while the particles are quite agglomerated in BL case. From the thermogravimetric analysis, the onset temperature of oxidation for BS particle is around 560 °C while it is approximately 760 °C for BL particles. It is also evident from the true colour flame images and emission spectra that the BS particles burn better than other two commercial boron particles. [ABSTRACT FROM AUTHOR]

Three different natural organic matter (NOM)-loading methods were compared for the adsorptive removal of 2-methylisoborneol (MIB) by superfine powdered activated carbon (SPAC) and conventionally-sized powdered activated carbon (PAC). The three NOM-loading methods were: NOM adsorption followed by MIB (MIB adsorption on NOM-preloaded carbon), MIB adsorption followed by NOM (MIB adsorption on NOM post-loaded carbon), and simultaneous NOM and MIB loading (MIB adsorption on NOM-simultaneously loaded carbon). MIB removals were similar for the smaller-sized carbon (SPAC) at higher AC dosages and at lower initial NOM concentrations. The similar MIB removals indicate direct site competition between MIB and NOM with MIB adsorption reversibility (complete desorption of MIB by NOM). At lower AC doses, especially for PACs, and at higher initial NOM concentrations, the adsorption of MIBs depended on the sequence of MIB or NOM adsorption. MIB removal was lowest for the NOM-preloaded carbon, followed by NOM-simultaneously loaded carbon. The highest MIB removal was achieved by post-loading of NOM, indicating that the adsorption is irreversible. MIB adsorption on SPAC was more reversible than on PAC, although the pore size distributions of the two carbons were similar. The high degree of adsorption irreversibility for PAC compared with SPAC indicated that pore blocking occurs due to NOM loading at the PAC particle surface. Images of the external adsorption were obtained using isotope mapping and 15 N-labeled effluent organic matter., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)