Silica Silicon Research Articles

Metabolites Obtained from Boraginaceae Plants as Potential Cosmetic Ingredients-A Review.

One of the challenges of the pharmaceutical and cosmetic industries is to deliver biochemical compounds that can be advantageous for the skin. Research on Boraginaceae taxa has confirmed their use in traditional medicine and proved the potential biological importance of various molecules in cosmetology. The main classes of valuable compounds associated with Boraginaceae taxa are fatty acids, including γ-linolenic acid, essential oils, phenolic acids (e.g., rosmarinic acid), flavonoids, anthocyanins, tannins, and saponins. Highly specific are naphthoquinone pigments (including shikonin) and allantoin. Another distinguishing feature is the accumulation of silica (silicon dioxide) in trichomes. Some taxa produce mucilages. However, pyrrolizidine alkaloids (PAs) with toxic properties are also found (mainly in Symphytum spp.); therefore, their applications should be avoided. Extracts or individual compounds of Boraginaceae plants are characterized by antioxidant, anti-inflammatory, antiseptic, anti-irritant, antiaging, and photoprotective activities. Boraginaceae products are widespread in the cosmetic industry as ingredients of creams, balms, lotions, gels, shampoos, lipsticks, perfumes, and deodorants. The most valuable for the cosmetic industry are raw materials obtained from the genera Alcanna Anchusa, Arnebia, Borago, Buglossoides, Cerinthe, Cordia, Echium, Ehretia, Eriodictyon, Glendora, Lappula, Lithospermum, Lycopsis, Macrotomia, Maharanga, Mertensia, Messerschmidia, Myosotis, Omphalodes, Onosma, Pulmonaria, Rindera, Symphytum, Trachystemon, and Trigonotis. Further research should focus on the search for active substances in other plants of the family.

Biogenic and lithogenic silicon along the GEOTRACES south West Indian Ocean section (SWINGS-GS02) and the islands mass effect on regional Si biogeochemical cycle

The distribution and cycling of biogenic silica (BSi) and lithogenic silicon (LSi) in the ocean play crucial roles in the global silicon cycle and marine ecosystem dynamics. This is especially the case in the Southern Ocean where diatoms constitute the predominant phytoplankton and participate in a major way to the biological carbon pump. This study presents an assessment of BSi and LSi concentrations along the GEOTRACES South West Indian Ocean Section (SWINGS, late austral summer 2021), where several and contrasting regions were encountered: oligotrophic Mozambique basin, HNLC (High Nutrient Low Chlorophyll) areas and regions fertilized by the Subantarctic islands. Suspended particles were sampled from Niskin bottles and in situ pumps, along with scanning electron microscope (SEM) observations and specific pigments measurements to support BSi and LSi analyses. With samples coming from a contrasting study area prone to diverse continental influences, our BSi and LSi results showed a reproducibility of 13 ± 7%, in the same range as the established protocol. BSi concentrations show a north-south gradient with maxima encountered in the Antarctic Zone, and contrasted results between HNLC open ocean areas and naturally fertilized regions in the vicinity of the Subantarctic islands. Some open ocean stations have unusually high BSi (e.g. > 5 μmol L−1) likely resulting from fertilization by aerosols, upwelling or island mass effect when they are downstream of the islands. Coupling of BSi with SEM observations and pigments measurements respectively showed diatoms were the most representative of the carrying phase of BSi and suggested silicification changes, induced either by heavily silicified diatoms or by micronutrient limitation in HNLC regions. BSi is often dominated by the smallest size fraction (0.45–5 μm) which represent 47 ± 23% of the total BSi based on 29 measurements on size fractionated samples. LSi results highlighted atmospheric inputs at the surface and nepheloid layers in the water column, which makes LSi overall a good indicator of the origin of lithogenic materials. SEM observations supported these results, enabling characterization of the diversity of lithogenic materials in the vicinity of the Subantarctic islands, more specifically volcanic ash around Heard Island, and within the nepheloid layers.

Applications of nanoscale silica (silicon dioxide) in the cosmetics industry

Applications of nanoscale silica (silicon dioxide) in the cosmetics industry

Thermal transport of glasses via machine learning driven simulations

Accessing the thermal transport properties of glasses is a major issue for the design of production strategies of glass industry, as well as for the plethora of applications and devices where glasses are employed. From the computational standpoint, the chemical and morphological complexity of glasses calls for atomistic simulations where the interatomic potentials are able to capture the variety of local environments, composition, and (dis)order that typically characterize glassy phases. Machine-learning potentials (MLPs) are emerging as a valid alternative to computationally expensive ab initio simulations, inevitably run on very small samples which cannot account for disorder at different scales, as well as to empirical force fields, fast but often reliable only in a narrow portion of the thermodynamic and composition phase diagrams. In this article, we make the point on the use of MLPs to compute the thermal conductivity of glasses, through a review of recent theoretical and computational tools and a series of numerical applications on vitreous silica and vitreous silicon, both pure and intercalated with lithium.

Erosion mechanisms of DLC coatings deposited on polyimide and silica substrates when exposed to a pulsed gas discharge

The influence of spark discharges on the surface morphology and chemical composition of resistive diamond-like carbon (DLC) coatings designed to prevent breakdowns in gas electron multipliers (GEMs) has been studied. DLC coatings with thicknesses of approximately 200 nm and 66 nm were deposited in an inert argon atmosphere on polyimide substrates by high current pulsed magnetron sputtering and on silica (silicon oxide) substrates by vacuum arc method. Based on the analysis of images of optical and scanning electron microscopy, it was established that, the region of interaction between the gas discharge channel and the coating surface presents an accumulation of erosion craters with a characteristic linear size in the range of 20–40 μm. The value of current density passing in the region of interaction between the plasma in spark discharges and the sample is estimated to be of the order of 105 A/cm2, which is sufficient to ablate the coating and create thermal stresses of magnitude ∼4 GPa at the interface between the coating and the substrate. Thus, pulsed surface erosion, insufficient adhesive strength of the coating to the substrate, and poor thermal conductivity should be considered as the key reasons for destruction of the DLC coating.

Effect of sintering temperatures on the physical, structural properties and microstructure of mullite-based ceramics

<abstract> <p>This study explored the impact of sintering temperature variations on the synthesis and characteristics of mullite ceramics derived from a composite blend of kaolinite clay, silica (silicon dioxide), and feldspar. Sintering temperatures ranging from 1100 to 1200 ℃ were systematically examined to analyze alterations in shrinkage, density, microstructure, elemental composition, and phase formation. The study revealed that an increase in sintering temperature led to decreased shrinkage due to improved particle packing and reduced porosity. Ceramic density showed a direct relation with sintering temperature, reaching the optimal density at 1175 ℃ and indicating efficient particle packing and compaction. Analysis through field emission scanning electron microscopy (FESEM) provided insights into microstructural changes, including alterations in grain morphology, porosity, and connectivity. Energy dispersive X-ray spectroscopy (EDS) clarified element distribution within the microstructure, offering valuable information on compositional variations. X-ray diffraction (XRD) examinations unveiled temperature-dependent phase transformations, which confirmed the successful formation of mullite during the sintering process. A sintering temperature of 1175 ℃ yielded the optimal ceramic quality and cost-effectiveness for high-temperature heating processes.</p> </abstract>

Mechano-chemical conversion of rice husk ash and gasifier-derived rice husk ash into porous silicon

Rice husk is an abundant agricultural biomass and a potential source of amorphous silica and porous silicon. To produce high-purity SiO2 and Si from rice husks, multiple steps of acid leaching to remove impurities and heat treatment to reduce residual carbon are necessary. In this study, a simple mechanochemical (magnesio-milling) experiment was conducted using an attrition mill to convert rice husk ash (RHA) and gasifier-derived rice husk ash (GRHA) into porous Si under various acid leaching (hydrochloric acid and lactic acid) and heat-treatment conditions. Three noteworthy results were obtained. First, eco-friendly lactic acid can be used instead of the harmful acid (hydrochloric acid). Next, the heat-treated GRHA was converted to Si via magnesio-milling without acid leaching. Finally, the carbon content (<0.3 wt%) of RHA and GRHA is a key factor affecting the conversion of SiO2 into Si based on elemental analysis. The purities of the Si samples prepared from RHA and GRHA, analyzed using inductively coupled plasma (ICP) mass spectrometry, were 97.66% and 95.62%, respectively. Furthermore, the porous Si prepared using RHA and GRHA can be utilized as a high value-add material such as an anode material for lithium-ion batteries and nanostructured materials.

Synthesis and cis-trans kinetics of an azobenzene-based molecular switch for light-responsive silica surfaces

Light-responsive materials design is an attractive research field that stimulates demand for the synthesis of novel molecular photoswitches. The novel photoswitches should be capable of being attached to a desired surface in order to provide it with light-responsive properties. The switchback to its ground state is expected to be gradual, with the possibility of acceleration. This study presents a comprehensive description of a chemical route to a molecular photoswitch based on an azobenzene derivative with a trifluoromethoxy group and a long alkyl chain. The photoswitch is capable of modifying submicrometer silica particles and silicon wafers as models of curved and flat surfaces, respectively. The thermal relaxation times of the synthesized azobenzene were studied in three different solvents: ethanol, chloroform, and toluene. The results reveal a significantly delayed relaxation process lasting for several days. This observation is found to be related to the polarity of the solvents used. To characterize the extensive thermal relaxation process, a methodology including the use of white-light pulses to accelerate cis-trans isomerization is suggested. The white light spectrum used in pulses affects thermal relaxation but does not alter the relaxation time extrapolated to zero. The density of the photoswitch molecules attached to particles varies from 0.7 to 1.7 molecules/nm2 as the initial amount of azobenzene in the reaction increases. Surface-attached photoswitches demonstrate reversible cis-trans isomerization behavior when exposed to UV and white light irradiation. A 14° contact angle change is observed when flat surfaces modified with photoswitches are irradiated with UV light.

Sol–Gel Silica Coatings for Corrosion Protection of Aluminum Parts Manufactured by Selective Laser Melting (SLM) Technology

Metal additive manufacturing is a rapidly growing field based on the fabrication of complex parts with improved performance. The advantages of using this technology include the production of shapes that cannot be produced by traditional machining technologies, the possibility of using trabecular reinforcing structures, and the ability to make parts with topological optimization that allow for increased performance and decreased mass of the parts produced. Metal parts produced by selective laser melting technology exhibit high surface roughness, which limits their direct implementation. Corrosion protection of these surfaces is difficult, especially for galvanic processes. This paper analyzes the possibility of using sol–gel silica (silicon oxide) coatings to effectively protect various surfaces of aluminum alloys produced by selective laser melting technology. Silicon oxide sol–gel protective coatings have demonstrated excellent chemical stability and corrosion resistance, being able to be applied in very thin layers. These properties make them excellent candidates for protecting additive-manufactured metal parts, especially as-built surfaces with a high surface roughness. Nanostructured silica sol–gel protective coatings have demonstrated excellent corrosion resistance and have the potential to replace the highly toxic chromium-based galvanic treatments. Using nanostructured silica sol–gel coatings, aluminum parts can be seamlessly integrated into circular-economy cycles.

Broadband Achromatic Terahertz Metalens Constituted by Si–SiO2–Si Hybrid Meta‐Atoms

AbstractMetasurfaces have proved to possess extraordinary properties and propelled the development of versatile functional devices in the terahertz domain, but the intrinsic dispersion severely impedes their broadband applications. Sporadic studies on achromatic terahertz metasurfaces are either subject to specific polarization operation or challenged in the fabrication process for extended bandwidth and numerical aperture. Herein a novel meta‐atom scheme made up of a silicon–silica–silicon sandwich‐shaped structure is presented that enlarges the propagation phase as well as improves the dispersion engineering capability at low losses. As a classic case, an achromatic metalens is constituted by these meta‐atoms and experimentally demonstrated which shows a remarkable achromatic focusing performance from 0.5 to 1.1 THz with a numerical aperture of 0.47 and an average efficiency as high as 43.1%. Continuous wavelet transformation analysis further proves the metalens has negligible group delay dispersion. This study not only demonstrates an outstanding terahertz achromatic metalens but also provides a novel meta‐atom paradigm for constructing achromatic metasurfaces such as holographic plate, beam deflector, and Bessel axicon, further not limited to THz bands.

Handling mode and polarization in fiber by fs-laser inscribed (de)multiplexer and silicon switch array

The emergence of dynamic optical switching has opened up new perspectives for lightening the ever growing load on the electrical switches and routers, to meet the increasing demand on high-speed and flexible data processing and management in fiber-optic communications. Despite diversity schemes of optical switching in the single-mode regime, multi-mode switching of the hybrid fiber and chip system enabled by photonic integrated circuits, especially for the fiber-chip-fiber system, is still an outstanding challenge. Here, we propose and demonstrate the mode and polarization transmission and switching fiber-chip-fiber system with few-mode fibers (FMFs), including the FMF links for mode- and polarization-division multiplexing data transmission, the femtosecond (fs)-laser inscribed 3-dimensional (3D) photonic lantern silica chip for (de)multiplexing and coupling between FMFs and chip, and the topology-optimized N × N non-blocking 2-dimensional (2D) silicon switch array chip for switching and routing. Using 30-Gbaud quadrature phase-shift keying signals on wavelength-division multiplexing (WDM) channels, the WDM-compatible hybrid mode/polarization transmission, switching and routing system with FMFs, fs-laser inscribed silica (de)multiplexing chip and silicon switch array chip are demonstrated in the experiment with favorable operation performance. The demonstration may open the door for developing robust multi-dimensional optical data processing in fiber-optic communication systems with versatile fibers and chips.

Problem of plane strain state of two-layer body in dynamic elastic-plastic formulation (Part I)

The design of composite and reinforced or armed materials is a requirement of the modern level of production and life. Many methods of calculation and design of such materials are successfully used. In this article, for the design of composite and reinforced materials, a technique for solving dynamic contact problems in more precise an elastic-plastic mathematical formulation is used. To consider the physical nonlinearity of the deformation process, the method of successive approximations is used, which makes it possible to reduce the nonlinear problem to a solution of the sequences of linear problems. In contrast to the traditional plane strain, when one normal stress is equal to a certain constant value, for a more accurate description of the deformation of the sample, taking into account the possible increase in longitudinal elongation, we present this normal stress as a function that depends on the parameters that describe the bending of a prismatic body that is in a plain strain state. The problem of a plane strain state of a beam made from the composite reinforced double-glazed material is being solved. The reinforced or armed material consists of two layers: the upper (first) thin layer of solid steel and the lower (second) main layer of glass. Glass is a non-crystalline, often transparent amorphous solid, that has widespread practical and technological use in the modern industry. The most familiar types of manufactured glass are "silicate glasses" based on the chemical compound silica (silicon dioxide, or quartz). Glass has high strength and is not affected by the processes of aging of the material, corrosion, and creep. In addition, this material is cheap and widely available. Glass can be strengthened, for example, in a melt quenching process. If the cooling is fast enough (relative to the characteristic crystallization time), then crystallization is prevented, and instead the disordered atomic configuration of the supercooled liquid is frozen into a solid state. This increases the strength properties of the glass. The reinforced composite beam is rigidly linked to an absolutely solid base and on which an absolutely solid impactor acts from above in the centre on a small area of initial contact.

Oil-palm management alters the spatial distribution of amorphous silica and mobile silicon in topsoils

Abstract. Effects of oil-palm (Elaeis guineensis Jacq.) management on silicon (Si) cycling under smallholder oil-palm plantations have hardly been investigated. As oil palms are Si accumulators, we hypothesized that management practices and topsoil erosion may cause Si losses and changes in spatial Si concentration patterns in topsoils under oil-palm cultivation. To test this hypothesis, we took topsoil samples under mature oil-palm plantations in well-drained and riparian areas of Jambi Province, Indonesia. The samples were taken from four different management zones within each oil-palm plot: palm circles, oil-palm rows, interrows, and below frond piles. We quantified mobile Si (SiM) and Si in amorphous silica (SiAm) by the extraction of CaCl2 and NaCO3, respectively. Both fractions are important Si pools in soils and are essential for plant–soil Si cycling. We further installed sediment traps on sloping, well-drained oil-palm plantations to estimate the annual loss of soil and SiAm caused by erosion. In well-drained areas, mean topsoil SiAm concentrations were significantly higher below frond piles (3.97 ± 1.54 mg g−1) compared to palm circles (1.71 ± 0.35 mg g−1), oil-palm rows (1.87 ± 0.51 mg g−1), and interrows (1.88 ± 0.39 mg g−1). In riparian areas, the highest mean topsoil SiAm concentrations were also found below frond piles (2.96 ± 0.36 mg g−1) and in grass-covered interrows (2.71 ± 0.13 mg g−1), whereas topsoil SiAm concentrations of palm circles were much lower (1.44 ± 0.55 mg g−1). We attributed the high SiAm concentrations in topsoils under frond piles and in grass-covered interrows to phytolith release from decaying oil-palm fronds, grasses, and sedges. The significantly lower SiAm concentrations in palm circles (in both well-drained and riparian areas), oil-palm rows, and unvegetated interrows (only in well-drained areas) were explained by a lack of litter return to these management zones. Mean topsoil SiM concentrations were in the range of ∼ 10–20 µg g−1. They tended to be higher in riparian areas, but the differences between well-drained and riparian sites were not statistically significant. Soil-loss calculations based on erosion traps confirmed that topsoil erosion was considerable in oil-palm interrows on slopes. Erosion estimates were in the range of 4–6 Mg ha−1 yr−1, involving SiAm losses in a range of 5–9 kg−1 ha−1 yr−1. Based on the observed spatial Si patterns, we concluded that smallholders could efficiently reduce erosion and support Si cycling within the system by (1) maintaining a grass cover in oil-palm rows and interrows, (2) incorporating oil-palm litter into plantation management, and (3) preventing soil compaction and surface-crust formation.

A preliminary study of porous ceramics with carbon black contents

<abstract> <p>This paper is a study of porous ceramics from a mixture of clay (kaolinite), silica (silicon dioxide), and feldspar by adding the carbon black (CB) with different contents. The results were presented in terms of apparent porosity, relative density, microstructure and porous characteristic, flexural strength and phase formation. As observed, the sintering at 1200 ℃ is the optimum temperature in this work. In comparison to the samples without CB content, the apparent porosity and relative density of ceramics are highly dependent on the CB contents. This might be attributed to the presence of porous structure as seen in SEM images on the fracture surface of ceramics. It also revealed that the addition of CB resulted in smaller pore sizes and a more uniform pore distribution. The creation of pores in porous ceramics was mainly attributed to the loss of shape of CB microspheres at high temperatures, as observed from SEM. The flexural strength of the sintered samples exhibited an average decrease from 60 to 55 MPa due to the presence of CB, which is typically known to reduce the mechanical properties with high porosity. In XRD results, the muscovite phase is represented by a few of peaks with significant intensities, while the rest peaks are of undetermined phase. The strongest peak at a 26° of 2θ angle, suggesting the presence of potassium and aluminium in the form of silicate minerals.</p> </abstract>

Impact of Excitation Intensity-Dependent Fluorescence Intensity Ratio of Upconversion Nanoparticles on Wide-Field Thermal Imaging

Erbium ion (Er3+)-doped upconversion nanoparticles (UCNPs) are frequently used for nanothermometry because their fluorescence intensity ratio (FIR) between two green emission bands at ∼525 and ∼545 nm is sensitive to temperature variation. One of the prerequisites for nanothermometry is that the FIR be independent of excitation intensity at constant temperature. In this work, the effect of excitation intensity on the FIR of core–double-shell NaYF4:Yb3+,Er3+@NaYF4:Yb3+,Nd3+@NaYF4 UCNPs was investigated in two environments. The first environment is in aqueous solution, and the second is a monolayer of UCNPs on top of a silica–silicon substrate in air. The experimental results showed that the FIR decreases with the excitation intensity at constant temperature in each case. We further found that the excitation intensity-dependent FIR indeed deteriorated the thermal images acquired by wide-field upconversion fluorescence microscopy, in which a Gaussian laser beam was used to excite UCNPs uniformly coated on a silica–silicon substrate. The nonuniform excitation intensity of the incident laser beam resulted in thermal images that showed nonuniform temperature distributions in a 100 μm range field of view, even though the whole sample was maintained at constant temperature in air. To tackle this problem, we first measured the excitation intensity and temperature dependence of the FIR and the excitation laser intensity distribution on the sample. We then developed a correction scheme to correct the thermal images. With our correction process, the temperature distribution on the sample can be accurately mapped even with nonuniform illumination.

FDTD Modeling of Au/Ag Nanoparticles Incorporated Au/Ag Photonic Crystal for Seeking the Maximal Localized Electric Field

AbstractPhotonic crystals (PhC) can be elaborately tailored to enhance the electromagnetic properties of materials and are drawing increasing attention in recent years. However, there is no sufficient theoretical framework to optimize photonic crystal designs for electric enhancement. A comprehensive theoretical model is presented to illustrate Au/Ag photonic crystal enhancement on electric fields and obtain a group of optimal photonic crystal parameters after large number of statistics and parameter scans. The second and deeper layers of PhC only contribute to both 5% extinction and absorption in the far‐field, and there is almost no difference in |E|max among different layers with the coefficient variation at ≈1%. Furthermore, increment of both lattice constants and NP diameters can trigger dramatic changes in |E|max, and the maximal |E|max derived from 190 nm AuNP (nanoparticle)‐Au PhC with the lattice constant of 560 nm. This structure is 47.7, 7.39, 4.63, and 2.69 times that of AuNP incorporated silica wafer, silicon wafer, Ag wafer, and Au wafer, respectively. The strong electric field enhancement attributes to not only the plasmonic effect but also the photonic crystal enhancement effect. The simulation procedures open the possibility of precise photonic crystal structure design and pave the way for various electric field enhancement applications.

Orange–Red Si Quantum Dot LEDs from Recycled Rice Husks

Nanomaterial toxicity and environmental concerns inspired us to develop a scalable method for fabricating quantum dots with a positive environmental impact. Milling rice creates billions of kilograms of rice husks yearly, which are an excellent source for high-quality silica (SiO2) and value-added silicon (Si) powders. Herein, we synthesize SiO2, porous Si, and Si quantum dots (SiQDs) from rice husks containing 20 wt % SiO2 using a conventional chemical synthesis method and investigate the structure, optical, and optoelectrical properties. The extraction yields of SiO2 and Si powders from rice husks are 100 and 86%, respectively. The final product, decyl-passivated SiQDs, consists of 3 nm crystalline particles that are soluble in an organic solvent. A colloidal solution of the decyl-passivated SiQDs exhibits orange–red photoluminescence at a wavelength of 680 nm, with a 21% quantum yield. This colloidal solution is used to develop a SiQD LED, resulting in orange–red electroluminescence.

Ocena narażenia zawodowego na frakcję respirabilną krzemionki krystalicznej powstającą w trakcie pracy

Among the forms of crystalline silica (silicon dioxide minerals) that are most common in the natural and work environments are quartz and cristobalite. They are used in various industries, including in the ceramics, glass and construction industries and pose a serious health risk to workers. The respirable of crystalline silica (RCS), which penetrates into the gas exchange area of the lungs causes chronic inflammatory reactions, followed by fibrotic changes in the lung tissue and, as a result, silicosis pneumoconiosis, often leading to lung cancer. Both employers and health and safety managers have great difficulties with the interpretation and application of legal provisions concerning the measurement of RCS concentrations (for the purpose of occupational exposure assessment) and the classification of work involving exposure to respirable dust generated during technological processes. The information in this article should help you resolve these issues.

Train a correct BP neural network as the input layer and as the training sample

For this problem, we train a correct BP neural network with the number of layers, material and thickness of each layer, emission spectrum pollution index as the input layer, as the training sample, and comprehensive thermal efficiency as the output layer, to obtain the network mapping relationship between comprehensive thermal efficiency and design parameters of multilayer structure. Then, through particle swarm optimization algorithm and genetic algorithm, six layers are obtained, which adopt silica silicon silica germanium silicon germanium structure, with refractive index of 21.7832 and thickness of 130.819. Currently, the corresponding thermoelectric conversion efficiency is the highest.

Irregular LIPSS produced on metals by single linearly polarized femtosecond laser

Currently, supra-wavelength periodic surface structures (SWPSS) are only achievable on silica dielectrics and silicon by femtosecond (fs) laser ablation, while triangular and rhombic laser induced periodic surface structures (LIPSS) are achievable by circularly polarized or linear cross-polarized femtosecond laser. This is the first work to demonstrate the possibility of generating SWPSS on Sn and triangular and rhombic LIPSS on W, Mo, Ta, and Nb using a single linearly polarized femtosecond laser. We discovered, for the first time, SWPSS patches with each possessing its own orientation, which are completely independent of the light polarization direction, thus, breaking the traditional rules. Increasing the laser power enlarges SWPSS periods from 4–6 μm to 15–25 μm. We report a maximal period of 25 μm, which is the largest period ever reported for SWPSS, ∼10 and ∼4 times the maximal periods (2.4 μm/6.5 μm) of SWPSS ever achieved by fs and ns laser ablation, respectively. The formation of triangular and rhombic LIPSS does not depend on the laser (power) or processing (scan interval and scan methodology) parameters but strongly depends on the material composition and is unachievable on other metals, such as Sn, Al, Ti, Zn, and Zr. This paper proposes and discusses possible mechanisms for molten droplet generation/spread/solidification, Marangoni convection flow for SWPSS formation, and linear-to-circular polarization transition for triangular and rhombic LIPSS formation. Reflectance and iridescence of as-prepared SWPSS and LIPSS are characterized. It was found that besides insufficient ablation on W, the iridescence density of Ta-, Mo-, Nb-LIPSS follows the sequence of melting temperatures: Ta > Mo > Nb, which indicates that the melting temperature of metals may affect the regularity of LIPSS. This work may inspire significant interest in further enriching the diversity of LIPSS and SWPSS.