Nano Silicon Research Articles

Nano Silicon Integrated Hard Carbon from Conjugated Microporous Polymer for High‐Efficient Lithium Storage

AbstractIt is a significant issue to develop silicon/carbon composite anode with high‐capacity and long cycling stability for lithium‐ion batteries. However, the huge volume expansion of silicon during lithiation leads to severe pulverization of silicon, resulting in serious capacity fading over cycles. Herein, nano silicon integrated hard carbon (20Si@HC, 20 wt% nano silicon) is prepared by pyrolyzing nano silicon in‐situ coated a conjugated microporous polymer (CMP). CMP‐derived hard carbon coating features developed porous structure, which not only deliver a high lithium storage capacity, but also provide enough space for the volume expansion of nano silicon. When evaluated as an anode for lithium‐ion batteries, the 20Si@HC delivers an impressive 1037 mAh g−1 at 0.1 A g−1 and a capacity retention ratio of 72.07% for 100 cycles at 0.6 A g−1, providing some reference for designing high‐capacity silicon/carbon composites.

Impact of different parameters in tribological properties of enset ventricosum/ terminalia arjuna fibers /SiO2 filler incorporation

Natural fiber composites have garnered considerable interest in recent years as sustainable substitutes for synthetic materials, owing to their environmental advantages, including renewability, biodegradability, and cost-effectiveness. Notwithstanding these benefits, there is a vital need to improve the mechanical and tribological characteristics of these composites for applications involving significant wear. This work used compression molding to make hybrid composites with natural fibers (NFs) and nano silicon dioxide (nSiO2) filler. The matrix material was epoxy, and the natural reinforcements were Enset ventricosum (EV) and Terminalia arjuna (TA) fibers. Tensile (TS), flexural (FS), and impact (IS) characteristics improved using 1:1 SiO2 filler and EV/TA fiber reinforcement. The combination of 6 wt% SiO2 and 45 wt% EV/TA improved mechanical performance. A high SiO2 filler (6 wt%) in polymer-based composites decreased Specific Wear Rate (SWR), according to Taguchi optimization. A better fiber-matrix interaction improves the mechanical characteristics of materials with fillers. This study optimized several responses using the new combined compromise solution (CoCoSo) method. Multi-criteria decision making is used here. This study introduces Method based on the Removal Effects of Criteria (MEREC) to determine objective criteria weights. Conclusions from experiments show ideal results. CoCoSo's optimization study showed that Enset ventricosum and Terminalia arjuna fiber (EV/TA) hybridization affected composites' tribological behavior.This hybrid fiber combination carried the most influence, followed by fillers. The optimal results were obtained with 6 wt% SiO2/25 wt% EV/TA Hybrid fiber, 1000 m Sliding distance (SD), 2 m/s Sliding speed (SS), and 10 N axial load (AL).

Is Microporous Carbon Confined Nano Si Composite the Best Anode Choice for High-Energy-Density Lithium-Ion Batteries?

Microporous carbon confined nano silicon composites (Si/m-C) are considered to be the best anode materials for high-energy-density lithium-ion batteries compared with the other Si-based materials such as SiO, due to high initial Coulombic efficiency (ICE) and capacity, as well as good cycling stability. However, there is a lack of multilevel comprehensive evaluation of Si/m-C, which poses potential risks to the commercial application. Herein, combined with quantitative titration, mechanical characterization, and bulk/interface evolution analysis, a systematic evolution of commercialized Si/m-C from the particle level to the cylindrical cell level is conducted, revealing the decay mechanism and proposing corresponding solutions. Among them, it is well demonstrated that the Si/m-C still withstands huge volume expansion of over 200% with poor mechanical strength, causing the electrical contact loss of active LixSi and severe interfacial side reactions. Moreover, even blending more than 90% graphite cannot completely suppress its volumetric strain, and the combination of highly flexible single-walled carbon nanotubes (SWCNT) is necessary. In response to this, the 32700-type cylindrical cell with a designed capacity of 9.5 Ah is assembled by mixing Si/m-C with 90% graphite and SWCNT as anode, achieving a long-term cycling stability over 300 cycles at 0.5C with a capacity retention of 94.8%.

Multi-scale ceramic self-extinguishing fire retardant coating based on scale armor layer

Currently, designing an efficient and broadly applicable (suitable for foams, wood, steel, plastic) fire-retardant coating remains a significant challenge. This work introduces a multi-scale micro-nanostructured hybrid fireproof coating. The composite features basic fillers that include ceramic glass microspheres, while its interior comprises an inorganic aerogel made from nano black phosphorus and silicon dioxide nanofibers for reinforcement, with a phosphorus-containing acrylic polymer serving as the base. Upon exposure to elevated temperatures, the coating’s surface transforms into a solid char layer resembling scale armor, effectively functioning as a robust fire barrier to protect the underlying substrate. The coating treated rigid polyurethane foam achieved an exceptionally high Limiting Oxygen Index of 45 %, outperforming comparable products. In terms of flame retardancy and smoke suppression, this innovative coating significantly reduces Peak Heat Release Rate (50.3 %) and Total Smoke Production (54.9 %). Notably, it exhibits rapid self-extinguishing capabilities within seconds during butane flame tests at temperatures exceeding 1100 °C, demonstrating remarkable resistance to high-temperature flames. This research offers a straightforward methodology for developing high-performance fireproof coatings, with promising applications across various industrial settings.

Effect of nano silicon nitride integration on the curing performance of DGEBA epoxy matrix at ambient temperature

Epoxy curing requires substantial thermal energy input and is constrained by the specimen’s scale, shape, and design, especially with autoclave processing. This challenge is addressed in the present study by incorporating Silicon Nitride (SiN) nanoparticles into an epoxy matrix to enhance curing efficiency at room temperature. High-resolution transmission electron microscopy (HR-TEM) demonstrated a uniform dispersion of nanofillers within the epoxy, indicating improved mechanical and thermal stress transfer between the matrix and the filler. The interphase thickness, determined to be 1.16 nm using Lipatov’s theory and differential scanning calorimetry (DSC) thermograms, suggests excellent matrix-filler interaction and a significant increase in cross-link density. Thermogravimetric analysis (TGA) revealed an increase in activation energy by 63 %, 101 %, and 113 % at heating rates of 10, 20, and 30 °C/min, respectively, indicating enhanced thermal stability of the nanocomposite. Additionally, the char yield increased by 7 %, 18 %, and 22 % at the same heating rates, signifying the formation of effective crosslinks, leading to a higher proportion of solid remnants rather than volatiles during degradation.

A Comparative Study of Nano and Micro-Sized Silicon in Lithium-Ion Cells with a Nickel-Rich Cathode

Reducing particle size has been widely adopted to mitigate the cracking and pulverization of silicon particles and to enhance electrode reaction kinetics for silicon electrodes in cycling. However, the increased surface area promotes parasitic reactions with electrolyte solvents. This work comparatively studies nano-sized silicon (Si-NP) and micro-sized silicon (Si-MP) as anodes in Li-ion cells using nickel-rich LiNi0.80Co0.1Mn0.1O2 (NCM811) as the cathode. The focus is on capacity, capacity retention, Coulombic efficiency (CE), and rate capability by changing the negative-to-positive capacity (N/P) ratio and charging cutoff voltage. It is found that Si-NP initially exhibits a CE above 90%, however, it rarely exceeds 98% in subsequent cycles, leading to rapid capacity fade. Additionally, increasing the N/P ratio and lowering the charging cutoff voltage does not obviously improve the cycling stability of Si-NP cells. Compared with Si-NP, Si-MP experiences lower capacity and lower CE in the initial several cycles. However, with continued cycling, both the capacity and CE gradually increase to a maximum and stably remain at ∼99.9%. The findings of this work suggest that, with its excellent rate capability, Si-MP may be more advantageous than Si-NP in developing practical Li-ion batteries, provided its low CE during initial cycles can be successfully addressed.

High-Performance Sheet-Type Sulfide All-Solid-State Batteries Enabled by Dual-Function Li4.4Si Alloy-Modified Nano Silicon Anodes.

The silicon-based anodes are one of the promising anodes to achieve the high energy density of all-solid-state batteries (ASSBs). Nano silicon (nSi) is considered as a suitable anode material for assembling sheet-type sulfide ASSBs using thin free-standing Li6PS5Cl (LPSC) membrane without causing short circuit. However, nSi anodes face a significant challenge in terms of rapid capacity degradation during cycling. To address this issue, dual-function Li4.4Si modified nSi anode sheets are developed, in which Li4.4Si serves a dual role by not only providing additional Li+ but also stabilizing the anode structure with its low Young's modulus upon cycling. Sheet-type ASSBs equipped with the Li4.4Si modified nSi anode, thin LPSC membrane, and LiNi0.83Co0.11Mn0.06O2 (NCM811) cathode demonstrate exceptional cycle stability, with a capacity retention of 96.16% at 0.5 C (1.18mA cm-2) after 100 cycles and maintain stability for 400 cycles. Furthermore, a remarkable cell-level energy density of 303.9Wh kg-1 is achieved at a high loading of 5.22 mAh cm-2, representing a leading level of sulfide ASSBs using electrolyte membranes at room temperature. Consequently, the chemically stable slurry process implemented in the fabrication of Li4.4Si-modified nSi anode sheet paves the way for scalable applications of high-performance sulfide ASSBs.

A novel approach to synthesize micrometer-sized porous Si/SiOx@C with internally and externally interweaved CNTs as a high performance anode for lithium-ion batteries

Silicon-based materials are prospective anodes because of the high capability of lithium (Li) storage, but the large volumetric expansion seriously destroys the integrity of the electrodes and further results in unsatisfactory cycling performance. Reasonable structure design based on low-cost nano silicon (Si) prepared by an feasible method is still an enormous challenge. Herein, the carbon-coated and cross-linked carbon nanotube/porous-Si/SiOx microspheres (CNT/SFDP-Si/SiOx@C) are firstly synthesized by combining an inverse water-in-oil microemulsion approach with magnesiothermic reduction. One high value-added route for utilizing silica fume as the precursor to form nano silicon is provided. The collaborative strategy via wired CNTs network, porous-Si/SiOx flexible matrix, and carbon coating is employed to keep the integrity and stability of electrode structure. Benefiting from the synergistic effect of the flexibility of CNTs network, protection of outer carbon shell, doping of diverse nitrogen (N) species, and accommodation of porous-Si/SiOx, CNT/SFDP-Si/SiOx@C exhibits excellent electrochemical performance. The long cycling lifespan with a reversible capacity of 675.8 mAh g−1 after 1000 cycles at 2 A g−1, a slight decay rate per cycle of 0.018 %, and a high-rate performance are simultaneously obtained. The prelithiated LiFePO4||CNT/SFDP-Si/SiOx@C full cell is also assembled, showing the reversible capacity of 129.4 mAh g−1 at 0.2C.

Nanocomposites of Glass/Sisal Fibre Strengthened Hybrid Polymer Matrix and the Effect of SiC Nanofillers on its Mechanical Features

Introduction: This study investigates the mechanical characteristics of hybrid sisal fibre (SF)/glass fibre (GF) reinforced composites with various weight % of nSiC fillers (nano silicon carbide). SF/GF/nSiC reinforced hybrid composite materials were developed following ASTM specifications using the vacuum infusion technique. Method: The resulting composites were then evaluated for their tensile, impact, hardness, and flexural characteristics. The findings reveal that none of the composites can imitate the GF composite's mechanical advantages despite hybridization and the nanofiller addition. The hybrid composite laminates with 2 wt.% nSiC show better mechanical response than competing hybrid composites. Results: The GF/SF/2%nSiC composite's impact strength and shore D hardness of the GF/SF/2%nSiC composite are 1.25 and 1.2 times greater than those of the GF/SF/3%nSiC composites. The GF/SF/2%nSiC composites exhibit 1.64, 1.5, and 1.8 times higher tensile strength, tensile modulus, and toughness modulus than the GF/SF/3%nSiC composites. The GF/SF/2%nSiC composite has a flexural modulus and strength of 1.22 and 1.41 times higher than the GF/SF/3%nSiC composites. Conclusion: The improved mechanical properties of the GF/SF/2%nSiC composite can be attributed to the firm bond between the fibre and matrix, the uniform dispersion of nanofillers, and reduced porosity. result: The tensile, impact, hardness, and flexural properties of the developed composites were assessed. SEM of the fractured surface was also performed to corroborate the results and determine the fracture mode.

Improved carbon fibers dispersion in geopolymer composites

Carbon fibers (CFs) reinforced alkali-activated (AA) ground granulated blast furnace slag (GGBFS) geopolymer composites have excellent mechanical and thermoelectrical properties, as well as low energy consumption and low CO2 emissions during their production. However, the dispersion of CFs in the geopolymer matrix is always a technical issue in the preparation of the green composite material. Therefore, this study comparatively investigated various dispersion methods, including, mixing sequence (pre-mixing and after-mixing methods), dispersing agent (nano silicon dioxide [nSiO2]), and ultrasonic treatment time (0, 15, 30, and 45 min), as well as CFs content (0.5, 1.0, and 1.5 wt% of GGBFS). The distribution of CFs was then qualitatively and quantitatively evaluated by a series of tests, such as flowability, electrical resistivity, flexural strength, scanning electron microscope (SEM) analysis, and X-ray computed tomography (CT). The experimental results showed that the proposed pre-mixing method provided excellent dispersion characteristics for CFs compared with the after-mixing method. The introduction of nSiO2 can enhance the dispersion of CFs and the mechanical and electrical properties of AA GGBFS geopolymer composites. At a carbon fiber content of 1.5 %, the pre-mixing method and the addition of nSiO2 dispersant reduced the resistivity of the 28-day geopolymer composites by 17.0 % and 38 %, respectively, compared with the after-mixing method. It is feasible to use X-ray CT scanning with the gray-scale frequency map to analyze the dispersion effect of CFs in AA GGBFS geopolymer composites. However, the results were not intuitive when less agglomeration of CFs occurred for the low content of CFs. The scanning method is more applicable to the sample with over 1.0 wt% CFs. The average pixel areas of uniformly dispersed CF bundles in the 2D images of the pre-mixing method and the addition of nSiO2 dispersant specimens were 3.32 % and 6.55 % higher than those of the after-mixing method, respectively. The 2D and 3D scanning results from the dispersion characteristics of CFs were consistent. 2D scanning could provide a time-consuming option for the measurement of CFs dispersion characteristics.

Microstructural evolution and investigation of mechanical properties of Al 7055 –Nano Si3N4 composites

In this paper an attempt has been made to develop the aluminium based metal matrix composites. Al7055 were chosen as base material and hard ceramic particulate nano silicon nitride as reinforcement. The composites were fabricated by using bottom pouring stir casting technique by varying weight percentage of Si3N4 in steps of (3 wt%, 6 wt% & 9 wt%) respectively and particle size of 30, 60 and 90nm. Morphological characterization of composites was conducted by using HRFESEM. The SEM result reveals that there is homogeneous distribution between the matrix and reinforcement. EDS mapping for prepared composites were done to identify the presence of alloying elements and phase distribution. XRD analysis is conducted for validation of the structural composition. Mechanical tests like tensile, micro Vickers hardness and impact test were performed on developed composites. The ultimate tensile strength of the composites at 9 wt% and particle size of 90 nm found to be diminishing due to severe agglomeration. The hardness value increases at 9 wt% and particle size of 30 nm. The toughness of the composites increased at 30 nm reinforcement size and 6 wt% as compared to higher weight percentage developed composites. Corrosion test were conducted as per ASTM G31 by weight loss method for different samples by dipping composite samples in 50 g Hcl solution for duration of 6 h and it was found that the corrosion resistance of the composites was higher while increasing the wt% of Si3N4 as compared to base matrix..

Creating value added nano silicon anodes from end-of-life photovoltaic modules: recovery, nano structuring, and the impact of ball milling and binder on its electrochemical performance

Recovery of silicon from end-of-life photovoltaic (PV) modules, purification, conversion to nano silicon (nano-Si), and subsequent application as an anode in lithium-ion batteries is challenging but can significantly influence the circular economy. Currently, a complete technology consisting of cross-contamination-free recovery of silicon wafers from end-of-life PV modules, a low-cost environmentally friendly purification process of the recovered PV silicon, a high yield conversion process of the recovered PV silicon into nano-Si, and its subsequent application in lithium-ion batteries is unavailable. This study provides a complete package including cross-contamination-free recovery, economical purification, reliable conversion to nano-Si, and efficient application of the end-of-life PV nano-Si in lithium-ion batteries. Hydrofluoric acid-free recovery and purification processes are demonstrated which can deliver large quantities of high-purity (≥ 99) silicon. In addition, the subsequent ball milling process produces very distinct nano-Si with different shapes and sizes. This study also creates a very effective nano-Si anode through in-situ crosslinking of water-soluble carboxymethyl cellulose and poly (acrylic acid) precursors. The integration of distinct PV nano-Si and water-soluble carboxymethyl cellulose-poly (acrylic acid) crosslink binder opens distinct possibilities to develop silicon-based practical anode for next generation low-cost lithium-ion batteries to power cell phones to electric vehicles.

Impact of blue-shifted effective joint density of electronic states on the photoluminescence of nanostructured silicon

Light emission from nanostructured silicon has triggered tremendous research interest for three decades. Yet, the exact mechanism of photoluminescence from silicon-based nano-systems is still not completely understood. It is generally believed that quantum confinement and surface chemistry play a combined role in determining the luminescence characteristics of nano silicon. In this work, we show that the evolution of electron-hole effective joint density of states, resulting from the relaxation of k-selection rule, can account for the much-observed temperature dependent shift of the luminescence spectra of nanostructured silicon. Deconvolution of the emission characteristics reveals three distinct radiative recombination channels those can be attributed to band-to-band, band-to-trap and trap-to-trap transitions. At temperatures below ∼200 K, the peak due to band-to-band transition exhibit a nearly linear blue shift with increasing temperature while at higher temperatures, this trend is reversed. The rate of variation of emission peak energy with temperature is also found to be dependent on the effective crystallite size. These results are explained in terms of shift in the effective joint density of state function of photogenerated electron-hole pairs. The shift provides experimental evidence of the pseudo-direct transitions in the quantum-confined nanostructure of silicon.

Nano-silicon embedded in mildly-exfoliated graphite for lithium-ion battery anode materials

Silicon-based materials have a high theoretical specific capacity and a low discharge potential, whereas the significant capacity fading owing to weak conductivity and volume exfoliation effect. The co-utilization of silicon and graphite has become a feasible method for realizing high-performance lithium-ion batteries (LIBs). Herein, the C@p-Si/ESG composite anode material with “sandwich” structure was obtained by electrostatic assembly of mildly-exfoliated graphite and electrostatic modified nano silicon, and subsequent coated with amorphous carbon on the surface of the material. The carbon coating and the mildly-exfoliated graphite form a buffer space, which alleviates the volume expansion effect of silicon in the process of lithium alloying. In addition, the SEI film is generated outside the carbon layer, reducing the consumption of the electrolyte and the occurrence of side reactions. C@p-Si/ESG exhibits a high charge–discharge rate and an excellent long-term cycle stability.

Amelioration of chromium toxicity in wheat plants through exogenous application of nano silicon

Chromium (Cr) contamination in agricultural soils poses a risk to crop productivity and quality. Emerging nano-enabled strategies show great promise in remediating soils contaminated with heavy metals and enhancing crop production. The present study was aimed to investigate the efficacy of nano silicon (nSi) in promoting wheat growth and mitigating adverse effects of Cr-induced toxicity. Wheat seedlings exposed to Cr (K2Cr2O7) at a concentration of 100 mg kg−1 showed significant reductions in plant height (29.56%), fresh weight (35.60%), and dry weight (38.92%) along with enhanced Cr accumulation in roots and shoots as compared to the control plants. However, the application of nSi at a concentration of 150 mg kg−1 showcased substantial mitigation of Cr toxicity, leading to a decrease in Cr accumulation by 27.30% in roots and 35.46% in shoots of wheat seedlings. Moreover, nSi exhibited the capability to scavenge oxidative stressors, such as hydrogen peroxide (H2O2), and malondialdehyde (MDA) and electrolyte leakage, while significantly enhancing gas exchange parameters, total chlorophyll content, and antioxidant activities (enzymatic and nonenzymatic) in plants grown in Cr-contaminated soil. This study further found that the reduced Cr uptake by nSi application was due to downregulating the expression of HMs transporter genes (TaHMA2 and TaHMA3), alongwith upregulating the expression of antioxidant-responsive genes (TaSOD and TaSOD). The findings of this investigation highlight the remarkable potential of nSi in ameliorating Cr toxicity. This enhanced efficacy could be ascribed to the distinctive size and structure of nSi, which augment its ability to counteract Cr stress. Thus, the application of nSi could serve as a viable solution for production of crops in metal contaminated soils, offering an effective alternative to time-consuming and costly remediation techniques.

Nanotechnology and high-performance concrete: Evaluating mechanical transformations

The High-performance concrete (HPC) is defined by the attained strength and durability that are superior to conservative techniques. The features of ordinary concrete that are achieved at certain times and locations, used to establish the standards for HPC. The use of nanotechnology in HPC is attracted significant attention globally because of its small particle sizes, filling capacities, enormous surface areas and strong macro quantum tunnel property. By adding nanotechnology to HPC, it increases the whole diameters of the cementations matrix, improves cement hydration and raises matrix density. This study provides a review of current developments in HPC and assesses the effects of different nanotechnology on HPC characteristics, to provide an in-depth understanding of the potential of nanotechnology reinforced in HPC. This review evaluates the mechanical characteristics of HPC containing compressive strength (CS) by applying nano calcium carbonate, nano silicon dioxide, nano titanium dioxide and carbon nano tubes. According to findings in this review, introducing different nanotechnology enhances HPC's mechanical properties while decreasing its flexibility. While integrating nanotechnology into HPC for the greatest possible outcomes in construction, review contributes to expand the collection of information in the area of building materials. To provide a low-impact construction material and an ecologically friendly solution, more consideration is required given to nanoparticles' antibacterial, self-cleaning, air depolluting and air-cooling properties. By increasing the reactivity of various fillers, including nanoparticles with other mineral admixtures reduces the quantity of cement needed in concrete.

Effects of moisture absorption analysis of kevlar/carbon/glass/polyurethane epoxy hybrid sandwich composites with nano silicon particles

ABSTRACT Hybrid sandwich polymer composites are widely used in aviation applications due to their attractive properties, such as their excellent strength capability, high modulus values, excellent stiffness properties, and greater wear resistance. This study aims to analyse the mechanical properties of degraded hybrid sandwich specimens exposed to moisture and investigate the moisture behaviour of the degraded sandwich panels. These panels are reinforced with woven fabrics made of kevlar, carbon, and glass fibres. The hand layup technique was employed to create the structures. The hybrid sandwich composite samples are submerged in normal seawater at ambient temperature for varied duration’s to measure the fibres’ water absorption characteristics. The study investigated the mechanical characteristics of an ageing moisture hybrid sample during tensile, flexural, and compressive tests. Novel stacking sequence arrangements (01 K/01 C/01 G/PUR/01 G/01 C/01 K) were used to enhance the stiffness, load-carrying capacity, yield strength, and other mechanical characteristics of the sandwich structures. The degraded sandwich panels demonstrated that water absorption significantly influences the tensile, flexural, and compressive properties of degraded sandwich structures compared with the results of regular sandwich panels. The tensile (31.67%, 40.40%, and 47.089%), flexural (63.13%, 66.05%, and 70.14%), compressive (33.14%, 39.37%, and 38.40%), and water absorption (3.75%, 3.97%, and 4.71%) test results were analysed.

Driving into the Future: Nano Graphene and Silicon Dioxide Enriched Kevlar Composites for Automotive Applications

Driving into the Future: Nano Graphene and Silicon Dioxide Enriched Kevlar Composites for Automotive Applications

تأثير جسيمات النانو من السيليكون على مكونات الفوتوكيمياء (النشاط البيولوجي) والخصائص الفسيولوجية لنبات الكزبرة تحت ضغط الماء

The present study was accomplished to scrutinize the efficiency of Nano silicon (NSi) as a foliar spray on (Coriander sativum) plants under water stress conditions during 2021/2022 season. Coriander plants were subjected to three water levels (100, 70 and 30% of field capacity). Plant leaves were sprayed with NSi in three different concentrations (3, 5 and 10 ppm) 14 days after germination. The results revealed that Coriander plants growth was significantly decreased under water stress, while NSi treatment showed a significantly enhanced plant growth (length and number of leaves per plant). Regarding biochemical constituents activity, total of alkaloids, phenol, flavonoids and fatty acids increased under water stress. Also, nutrient elements (P & Mg and Na) increased. Plant hormones such as gibberellic acid (GA3) and ascorbic acid (vitamin C) significantly decreased under both 70% and 30% FC, while abscise acid (ABA) increased. In the interim, the three different concentrations of NSi significantly improved carbohydrates concentration and adjustment of osmotic stress. Application of NSi at different concentrations significantly improved nutrients contents (N, P, K, Mg, Ca, Fe, Zn, Mn) mainly under moderate and severe water stress (70%, 30% FC). Generally, the profound concentration of NSi tested during the experiment was 5 ppm for ameliorating water stress. The present investigation showed that the application of NSi might be a promising method to enhance the plant growth, biochemical ingredients and crop productivity of Coriander plants grown under water stress conditions.

Investigation of numerical phase transition of nano-enhanced SiC/paraffin wax PCM in solar-assisted water desalination system

Adding nanoparticles in phase change material (PCM) is a new trend for enhancing their thermal energy-storing ability as well as thermal conductivity. From this point of view, a numerical study is carried out to examine the addition of silicon carbide nanoparticles in paraffin wax PCM, used as heat energy storing material in a semi-cylindrical solar water desalination system. The PCM temperature is maintained at 52 °C and the semi-cylindrical tubular section has a wall temperature of 85 °C. The top plane section of the tubular solar collector is made up of graphite material. A semi-circular cross-section is selected for numerical analysis. A finite volume solver is used for solving thermal and fluid flow governing equations. A pressure staggering option algorithm is applied for pressure–velocity coupling. The temporal parameters like temperature, velocity contours, melting fraction, enthalpy, and entropy of nano silicon embedded paraffin wax PCM are widely discussed. The results clearly show that the phase transition of solid PCM to fluid PCM is greatly influenced by nanoparticle addition and enhances the rate of heat transfer. Initially for the first 60 min the melting fraction and temperature of PCM remain uniform as the time step increases above 60 min the behavior of PCM changes abruptly which clearly indicates the random distribution of nanoparticles within the PCM. A critical time and temperature limit exists for nanoparticles-based PCM beyond which, the thermal efficiency of the solar water desalination system gets influenced.