Potassium Silicate Research Articles

Citrus bliss: potassium, sodium, and calcium silicates secrets for post-harvest diseases of fruit defense

Biotic stress significantly challenges the global citrus industry. Major post-harvest issues include diseases caused by Penicillium digitatum, Penicillium italicum, Geotrichum citri-aurantii, Alternaria alternata, and Phytophthora citrophthora. The negative impact of chemical fungicides on the environment and health necessitates eco-friendly alternatives. This study examines the effectiveness of sodium, potassium, and calcium silicates against common citrus diseases. In vitro tests evaluated mycelial growth inhibition using silicate concentrations from 0 to 10,000 ppm after 7 days at 25°C. Sodium silicate showed the highest efficacy, completely inhibiting P. digitatum and P. italicum at 2000 ppm. Potassium and calcium silicates achieved 100% inhibition against Penicillium spp. at a concentration of 1%. In vivo tests on Sidi Aissa clementines assessed the preventive and curative effects of 1, 2, and 6% silicate salt solutions. Sodium silicate prevented 41% of brown rot, 72% of sour rot, and 100% of green mold at 6%. Calcium silicate at 6% significantly reduced blue mold and black rot by 32% and 74%, respectively. Sodium silicate was most effective in curative treatments, suggesting its potential as a pre- or post-harvest spray to control P. digitatum, P. italicum, and G. citri-aurantii.

Applying Alkali Activator and Hydrophobic Agents in Clay-Based Mortars for Enhanced Properties

Clay-based mortars are susceptible to water intake and exhibit low mechanical strength, presenting challenges in their application within the construction sector. This research addresses these vulnerabilities by investigating the combination of alkali activators with waterproofing agents, specifically a nano-clay and an acrylic emulsion, to enhance the properties of clay mortars. Alkali-activated materials are known for their superior mechanical properties and sustainable potential, especially when derived from low-cost by-products. Recent studies have focused on alkali activation using clays and soils as precursors to improve their physical and mechanical properties while increasing durability. However, the high absorbency of these mortars remains a concern, as it can lead to matrix degradation. Therefore, to address these problems, this research studied the combination of a highly alkaline activator (potassium metasilicate) with hydrophobic agents, such as a nano-clay and an acrylic emulsion, using two different clayey soils. The results indicated that potassium metasilicate (PO) enhanced the mechanical properties and stability for both aluminosilicate systems, while nano-clay (PONC) significantly reduced the capillary absorption through time, especially in A2 systems. The addition of acrylic emulsion (POD) proved highly effective in both systems, significantly improving durability. By integrating these agents, the mortar systems were protected against water intake, while durable construction materials were formed.

Transient Expression of Nicotiana tabacum Silicon-Induced Histidine-Rich Defensins in Nicotiana benthamiana Limits Necrotic Lesion Development Caused by Phytopathogenic Fungi.

Silicon (Si) supplementation permits plants to better deter infection. Supplementing hydroponically-propagated Nicotiana tabacum with 1 mM potassium silicate (K2SiO3) reduced necrotic lesion development on detached leaves by both Botrytis cinerea and Sclerotinia sclerotiorum. Previously, a family of Si-induced genes was identified in N. tabacum. These genes were members of the Solanaceous Histidine-Rich Defensin (HRD) superfamily and were termed NtHRD1s (the first identified family of Nicotiana tabacum Histidine-Rich Defensins). Defensins were originally identified to participate in innate immunity. Thus, the NtHRD1s were tested for antimicrobial effects on plant pathogens. Transient expression of NtHRD1 genes within Nicotiana benthamiana leaves restricted the development of necrotic lesions caused by B. cinerea and S. sclerotiorum. Thus, the NtHRD1s may be an additional Si-responsive factor conferring beneficial effects on plants.

Characterization of Mineralogical and Mechanical Parameters of Alkali-Activated Materials Based on Water Sediments Activated by Potassium Silicate

Characterization of Mineralogical and Mechanical Parameters of Alkali-Activated Materials Based on Water Sediments Activated by Potassium Silicate

Effects of foliar silicon and nitrogen applications on winter color retention and spring green-up of zoysia grass

Zoysia japonica Steud. (zoysia grass), with its high drought, shade, and salt tolerance, it is an excellent choice for green areas. However, in regions with subtropical climates, it goes into winter dormancy with a loss of green color and functionality, which is a main barrier to its widespread use. The application of silicon and nitrogen in fall was hypothesized to enhance winter color retention of Z. japonica. This study assessed the impact of fall (late-season) nitrogen (0, 2.5, or 5.0 g/m2 ammonium sulfate) and foliar silicon (0, 3, or 6 mL/L potassium silicate) applications on the winter color retention of Z. japonica grown in the field. The experiment was conducted over two consecutive growing seasons in Antalya, Türkiye. Turfgrass quality, color, chlorophyll content, shoot density, and winter dormancy were all improved by late-season nitrogen application. Overall, two sequential nitrogen applications at 5 g/m2 in fall provided 65% to 100% green coverage with acceptable turfgrass quality during fall and winter, indicating the possibility of maintaining the year-round green color of Z. japonica in subtropical climates. However, the silicon treatment did not affect the winter color retention of Z. japonica. The apparent lack of a beneficial response of Z. japonica to the silicon application might be due to the dose, application methods, and silicon source.

Protection behavior of Ti-SiO2 modified potassium silicate coating on K447a alloy at 1000 °C

Potassium silicate coatings cured by calcium hydrogen phosphate and modified by fillers of Ti and SiO2 powders were prepared on K447A alloy at 120 °C. The influences of Ti, SiO2 and both powders on the oxidation behavior of the coated specimens were investigated at 1000 °C for 100 h in static air by thermogravimetry, SEM, XRD and EPMA. The bare K447A alloy suffered severe oxidation at 1000 °C, and the TGO was found to be composited of an outer layer of mixtures of NiCr2O4, CoAl2O4 and rutile TiO2, and an inner α-Al2O3 layer. The potassium silicate coating without filler showed local damages where formation and rapid rupture of bubbles occurred and consequently the local substrate was oxidized. The SiO2 powder in the coatings is more capable of reducing O diffusion thru the coatings than the Ti powder, while the latter is more effective in getting rid of bubble rupture than the former. Thus, the coating modified by 10 wt% Ti and 20 wt% SiO2 showed the best protective performance.

Optimization of Flexural Strength of Sawdust Ash Blended Geopolymer Concrete

release of greenhouse gases linked to the manufacture of cement. Geopolymer as a binder for making concrete consists of two (2) main components; (1) the alkaline liquid consisting of sodium or potassium silicate and sodium or potassium hydroxide and (2) source material of geological origin or by-products rich in silica and alumina. The combination proportions utilised in this investigation were formulated utilising Scheffe's (5,2) basic lattice mix design approach with the intent to create the trial mix and the control mix. A total of thirty (30) geopolymers concrete sample mixes were made in the laboratory, with fifteen samples for trial mixes and fifteen mixtures for control mixes. These mixtures were used to appraise the performance of the sawdust ash geopolymer concrete in term of its flexural strength property. The study used sawdust ash as the source material and investigation revealed that subjecting sawdust ash to pyrolysis without oxygen has a notable impact on the pozzolanic characteristics of the constituent. Consequently, this also affects the flexural qualities of the concrete. Furthermore, it has been shown that softwood sawdust exhibits superior pozzolanic properties when compared to hardwood sawdust. The study revealed that the optimum flexural strength of sawdust ash blended geopolymer concrete is 3.3002 MPa and the corresponding mix deign obtained. Computer programs were created using Matlab and used for the optimization and prediction of the flexural strength of sawdust ash based geopolymer concrete.

Exploring wine yeast natural biodiversity to select strains with enological traits adapted to climate change

Wine is widely consumed throughout the world and represents a significant financial market, but production faces increasing challenges. While consumers progressively value more complex flavor profiles, regional authenticity, and decreased use of additives, winemakers strive for consistency among climate change, characterized by rising environmental temperatures and sun burn events. This often leads to grapes reaching phenolic maturity with higher sugar levels, and increased microbial spoilage risk.Herein, we addressed these dual concerns by investigating the use of autochthonous Saccharomyces cerevisiae strains for fermentations of grape musts resulting from these altered conditions. We characterized underexplored repositories of naturally-occurring strains isolated from different environments and geographical regions, regarding adequate enological properties (e.g., high cell growth, reduced production of H2S, ethanol and acetic acid, increased SO2 resistance, killer activity), and other less frequently investigated properties (resistance to osmotic stress, potassium and aluminium silicates and fungicides). The phenotypic data were organized in a biobank, and bioinformatic analysis grouped the strains according to their characteristics. Furthermore, we analyzed the potential of four Portuguese isolates to be used in fermentations of grape musts with high sugar levels, uncovering promising candidates. This research therefore contributes to ongoing efforts to increase sustainability and quality of wine production.

Microbial and Biochemical Biofungicides Ineffective Against Alternaria Black Spot on Organic Kale

In South Carolina, the disease black spot on kale is caused by the fungi Alternaria brassicicola and A. japonica. Because all kale cultivars are presumed to be susceptible, organic producers may apply biofungicides to prevent or manage black spot. Microbial and biochemical biofungicides were tested in the greenhouse (12 products) and the field (10 products) against black spot caused by both Alternaria spp. on organically produced kale. Thereafter, three biofungicides (copper hydroxide, potassium silicate, and Reynoutria sachalinensis extract) were tested in the field on three kale cultivars. Although several biofungicides reduced black spot in the greenhouse compared with the water-treated control, no biofungicides did so in the field even though they were applied preventatively before plants were inoculated. Biofungicides also did not increase the weight of healthy leaves compared with the water-treated control in any field experiment. Conversely, two biofungicides that increased the severity and incidence of black spot in the greenhouse, B. amyloliquefaciens F727 and potassium bicarbonate, reduced weights of healthy leaves in the field. On average, curly kale cultivar Winterbor had fewer diseased leaves than curly kale cultivar Darkibor, and lacinato kale cultivar Toscano had fewer diseased leaves than curly kale. Winterbor also consistently produced greater healthy leaf weight than Darkibor. Biopesticides are not recommended against black spot on organic kale. [Formula: see text] Copyright © 2024 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .

Effect of Silicate Addition on ZnO Formation during Zn Discharging Process

Rechargeable zinc batteries have been attracting extensive attention as promising candidates for next-generation energy storage, owing to their intrinsic safety, mature recycling processes, low material cost and high theoretical energy density.[1] Nevertheless, there are still several issues holding back the development of zinc batteries, such as the capacity loss due to Zn passivation and poor cyclability caused by Zn dendrite formation. [2] In the past few years, efforts have been made to improve the performance of zinc batteries, among which electrolyte modification with additives is the most widely used. [3] For further development of zinc batteries towards practical application, it is also essential to deepen the understanding of chemical state changes in a working Zn electrode. In our previous work, Zn dissolution−passivation behavior with ZnO formation during Zn discharging process has been systematically elucidated via in-situ analysis. [4] Herein this work, through comparative studies with silicate addition in the electrolyte, the correlation between ZnO formation and the discharging performance of Zn anodes is further clarified, shedding new insights into further optimization of zinc batteries.Firstly, various electrolyte additives were evaluated during Zn discharging at a current density of 40 mA/cm2. As a result, potassium silicate addition with an optimum concentration of 100 mM effectively enhanced the discharge capacity of Zn anode. Effects of silicate addition on Zn discharging process were then further investigated. After 500 s of discharging, ZnO layer with a thickness around 7 um is formed on Zn anodes, which is attributed to the dehydration of supersaturated zincate ions. [4] It is observed that as-formed ZnO petals turned from sharp to round with silicate addition. Moreover, a porous ZnO layer was formed with silicate addition, while a compact one was obtained without any additives. Accordingly, it is assumed that silicate may form adsorption or coordination with ZnO particles, leading to morphology and porosity changes in ZnO.Further analyses were carried out to verify whether the chemical state of ZnO changes with silicate addition. The TEM-EDS mapping result and XPS depth profile indicate that Si is uniformly distributed within the ZnO layer. Moreover, the presence of Si-O bond is confirmed, along with both Zn 2p 2/3 and O 1s peak shifts towards higher binding energy side. Accordingly, the coordination between silicate and ZnO via the formation of Si-O-Zn bridge is suggested, which is also supported by the DFT calculation result, as a stable existence of silicate on ZnO can be achieved.On the other hand, it is noticed via XRD and HRTEM characterization that the crystallite size of ZnO became smaller with silicate addition. Moreover, ZnO formed with silicate addition presented lower crystallinity with higher defect contents, as evidenced by Raman spectra. Given the above, it is considered that silicate modulates the electronic structure of ZnO molecules via the Si-O-Zn bonding, thereby suppresses ZnO crystal growth and particle aggregation, which eventually contributes to a loose ZnO structure that can maintain the activity of Zn anodes. With the discussion of ZnO formation herein, we hope this work may open a new avenue for developing high-performance zinc batteries.AcknowledgementsThis study was supported by the Research and Development Initiative for Scientific Innovation of New Generation Batteries (RISING) Projects, RISING3 [JPNP21006], commissioned by the New Energy and Industrial Technology Development Organization (NEDO), Japan.[1] P. Ruan et al., Angew. Chem., 2022, 134, e202200598[2] W. Shang et al., Energy Storage Mater., 2020, 31, 44–57[3] S. Guo et al., Energy Storage Mater., 2021, 34, 545–562[4] T. Wang et al., Energy Environ. Mater., 2023, 0, e12481

Performance of coal slime-based silicon fertilizer in simulating lead-contaminated soil: Heavy metal solidification and multi-nutrient release characteristics

High-ash coal slime-based silica fertilizer (CSF) has the potential to provide mineral nutrients and passivate lead (Pb) in the soil to ensure the sustainable development of the coal industry and agriculture. This study investigated the performance and passivation mechanism of CSF, which contains potassium tobermorite and potassium silicate as the main components for soil improvement. Leaching experiments showed that low-crystalline muscovite was the only crystalline phase for CSF etching and that the silicon (Si), calcium (Ca), and potassium (K) in CSF had significant citric solubility. Soil cultivation and planting trials confirmed the ability of CSF to neutralize soil acidity, increase available soil Si and K, improve exchangeable Ca content, reduce the bioefficacy of Pb (exchangeable Pb by 19–75 % and carbonate-bound Pb by 6–18 %), and increase residual state Pb content. Compared to untreated Pb-contaminated soil, the 0.4 % CSF treatment reduced Pb in Chinese cabbage (Brassica rapa) by 25 % and increased plant biomass, Ca, and K by 37 %, 36 %, and 4 %, respectively. At the same time, soil pH increased by 0.58, and residual state Pb increased by 5 %. In CSF-treated soils, lead silicate is the dominant form of Pb present in the residual state. First-principle calculations showed that Pb3Si2O7 (cohesion energy −1.98 eV) formed by the passivation of Pb by CSF had greater stability in the soil compared to lead carbonate (PbCO3) (cohesion energy −1.38 eV) and lead sulfate (PbSO4) (cohesion energy −1.41 eV). This work shows the promising application of coal slime mineral fertilizers prepared using hydrothermal methods for soil improvement.

The mathematical model for the optimization of compressive strength of sawdust ash geopolymer concrete

Geopolymer concrete offers an eco-friendlier option compared to traditional cement, as it lowers greenhouse gas emissions during production. It consists of an alkaline solution with sodium or potassium silicate and sodium or potassium hydroxide, as well as a source material abundant in silica and alumina. For this study, thirty geopolymer concrete samples were produced in the lab using a mix design approach from Scheffe’s (5,2) model. The focus of the research was on maximizing the compressive strength of the concrete, especially when incorporating sawdust ash as the source material. The findings indicated that subjecting sawdust ash to pyrolysis in the absence of oxygen significantly impacts its pozzolanic properties and, consequently, the characteristics of the concrete. The research determined the optimal compressive strength of geopolymer concrete incorporating sawdust ash to be 21.673 MPa, along with specific concentration ratios of NaOH, Na2SiO4 to NaOH, sawdust ash in the binder, water to binder, and activator to sawdust ash at 10.5415, 2.0446, 38.6307, 0.0363, and 2.5882 respectively. Furthermore, MATLAB-based computer programs were utilized to optimize and forecast the ideal mixture proportions for sawdust ash-based geopolymer concrete.

Influence of Spraying Kaolin and Potassium Silicate on Quality, Storability and Fungal Diseases Control of “King Roby” Grapevine

Influence of Spraying Kaolin and Potassium Silicate on Quality, Storability and Fungal Diseases Control of “King Roby” Grapevine

Utilization of silicon dioxide nanoparticles and silicon salts to enhance astaxanthin production in Haematococcus Pluvialis

Haematococcus pluvialis is a type of microalgae that is commercially important as it is the primary source of natural astaxanthin - a potent antioxidant used in nutraceuticals, cosmetics, food, and aquaculture industries. Various nanoparticles and chemicals have been used to stimulate the growth of H. pluvialis to increase astaxanthin production. In this study, silicon nanoparticles were synthesized from tetraethyl orthosilicate (TEOS) and characterized to ensure the pure synthesis of uniform nanocrystals of silicon dioxide. The microalgae were cultivated in optimal Haematococcus medium (OHM) under specific conditions, including a temperature of 25 °C, a pH of 7, and a light intensity of 50 μmol. s−1.m−2 for 12 h of light and 12 h of darkness. To study the amount of viability and astaxanthin production, the microalgae were exposed to different concentrations of silicon, sodium silicate, calcium silicate, and potassium silicate. The highest astaxanthin production (194 mg/g) was obtained after stimulation at 200 μg/ml of silicon compared to the control after 15 days by high-performance liquid chromatography (HPLC) technique. Therefore, it can be concluded that certain concentrations of silicon and silicon salts can be considered a suitable stimulus to produce astaxanthin in the H. pluvialis microalgae. This study highlights the potential of using silicon nanoparticles as a stimulant for astaxanthin production in H. pluvialis, which could have significant implications for the nutraceuticals, cosmetics, food, and aquaculture industries.

Correction: Sharma et al. Effects of Funneliformis mosseae and Potassium Silicate on Morphological and Biochemical Traits of Onion Cultivated under Water Stress. Horticulturae 2022, 8, 663

The Horticulturae Editorial Office wishes to make the following changes to the author’s paper [...]

Improvement of Buildings’ Air Quality and Energy Consumption Using Air Purifying Paints

Among the existing techniques to mitigate the problem of contamination in the indoor environment, photocatalytic technology is considered to be the most promising solution in terms of effectiveness and cost. To that end, in the frame of the LIFEVISIONS project, a novel photocatalytic powder (photo-powder) was mixed in paints’ matrix, producing a photocatalytic building material (photo-paint) able to improve indoor air quality (IAQ), upon its application, without downgrading paint physical properties. As a result, of IAQ improvement, less energy will be needed from ventilation systems, addressing not only health issues related to air quality but also energy reduction targets. Many powder formulae were synthesized using different synthetic pathways, concentration of dopants, and TiO2 particles’ size. They were tested in a photocatalytic reactor (lab-scale tests), according to CEN TS 16980-1:2017, under visible light and the results showed that the most promising photocatalytic performance degrades 85.4% and 32.4% of nitrogen oxide (NO) and toluene, respectively. This one was used for the production of two different kinds of paints, organic (with organic binder) and inorganic (with potassium silicate binder), in an industrial scale. Both were tested in the Demo Houses’ prototype demonstrator (real-scale tests) with an ultimate scope to estimate their effectiveness to degrade air pollutants under real-world conditions. In addition, the reduced energy consumption as a result of less ventilation needs was calculated in Demo Houses. More specifically, the energy reduction based on simulation results on Demo Houses was more than 7%. Although lab-scale tests showed better photocatalytic performance than the real scale, the efficiency of the paints under a more complicated environment was very promising.

Strawberry field trial in Australia demonstrates improvements to fruit yield and quality control conformity, from application of two biostimulant complexes

ABSTRACT Strawberry (Fragaria x ananassa) is a popular fruit consumed for its desirable flavour, aroma and colour and is considered a functional food due to its antioxidant properties. Noting the need for farmers to increase productivity to meet increasing consumer demands, this study aimed to explore the potential of biostimulants to enhance strawberry cultivation. Herein, a field trial was conducted on a commercial strawberry farm, wherein 1944 strawberry plants received fertigation supplementation with either a control solution (nutrients only) or nutrients combined with one of two biostimulant complexes (BCs). Biostimulant complex 1 (BC1) was composed of molasses, Aloe vera extract and fish-hydrolysate, and biostimulant complex 2 (BC2) was composed of potassium silicate and potassium phosphite. Results indicated that BC1 maintained total yields but increased the sellable proportion and decreased the proportion of waste. In contrast, BC2 increased total yields with both sellable yields and waste increased. No significant changes were observed for indicators of consumer preference (flavour, aroma and fruit colour), however, on-average large increases were observed to indicators of fruit antioxidant properties (phenolic and flavonoid content). Accordingly, these results support the utilisation of biostimulants as a strategy to improve strawberry on-farm productivity without compromising consumer quality measures.

Field evaluation of biostimulants on growth, flowering, yield, and quality of snap beans in subtropical environment

The cultivation of snap beans (Phaseolus vulgaris L.) in subtropical regions faces environmental challenges leading to potential declines in yield. This study explores the efficacy of biostimulants as a solution, specifically investigating spraying treatments with 6-benzylaminopurine (6-BA), chitosan (Ch), triacontanol (TRIA), and potassium silicate (KSi) on the snap bean cv. Paulista. Over two growing seasons with late sowing and elevated summer temperatures, the research assesses growth, flowering, yield, and quality. Notably, 5 ppm TRIA demonstrates the most significant impact on plant growth and leaf nutrient content. Treatments with 40 ppm 6-BA, 5 ppm TRIA, or 200 ppm KSi exhibit notable effects on inflorescence flower count and flowers per plant. These treatments prove most effective for crucial green pod yield measures, including the number and weight of marketable pods. Moreover, 40 ppm 6-BA or 5 ppm TRIA significantly enhances pod characteristics, such as length, diameter, and weight, consistently improving over both seasons. Particularly, 5 ppm TRIA outperforms in enhancing the chemical quality of pods throughout the study. Overall, the findings suggest that the application of 5 ppm TRIA offers the most favorable enhancements for the growth, flowering, productivity, and quality of snap bean plants in subtropical field conditions.

Corrosion behavior of low melting glass modified potassium silicate coating under the synergy of solid NaCl deposit and water vapor at 700 °C

The effects of LMG (SiO2–BaO–Al2O3–TiO2–Na2O–K2O–ZnO) modification on the performance of potassium silicate coatings on Ti–6Al–4V alloy during tests of either H2O/O2- or NaCl/H2O/O2- corrosion were investigated at 700 °C for 500 h using thermogravimetric, SEM, EPMA, and XRD. Adding 10-30 wt% LMG particles into the potassium silicate solution did not impair the intact and the surface roughness of the coatings and improved the resistance of the coatings against humid oxygen corrosion and NaCl/H2O/O2-induced corrosion. For the humid oxygen corrosion, the improvement was enhanced when the amounts of LMG was increased. However, the LMG10 coating with 30 vol% LMG had the most excellent corrosion resistance, the formation of titanate was prohibited; the coatings with more LMG additions were less protective than LMG10 though better than the coating without LMG.

Determining the Most Appropriate Concentration for Spraying with Potassium Silicate and the Best Planting Date for the Vegetative Growth Traits of Safflower (Carthamus tinctorius L.)

Determining the Most Appropriate Concentration for Spraying with Potassium Silicate and the Best Planting Date for the Vegetative Growth Traits of Safflower (Carthamus tinctorius L.)