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Materials (Basel, Switzerland) Sep 2022The poly(lactic acid) (PLA) biodegradable polymer, as well as natural, siliceous reinforcement in the form of diatomaceous earth, fit perfectly into the circular economy...
The poly(lactic acid) (PLA) biodegradable polymer, as well as natural, siliceous reinforcement in the form of diatomaceous earth, fit perfectly into the circular economy trend. In this study, various kinds of commercial PLA have been reinforced with diatomaceous earth (DE) to prepare biodegradable composites via the extrusion process. The structure of the manufactured composites as well as adhesion between the matrix and the filler were investigated using scanning electron microscopy (SEM). Differential scanning calorimetry (DSC) analyses were carried out to determine crystallinity of PLA matrix as function of DE additions. Additionally, the effect of the ceramic-based reinforcement on the mechanical properties (Young's modulus, elongation to failure, ultimate tensile strength) of PLA has been investigated. The results are discussed in terms of possible applications of PLA + DE composites.
PubMed: 36143522
DOI: 10.3390/ma15186210 -
Materials (Basel, Switzerland) Apr 2022This work studies the possibility of using geopolymer materials to enhance the mechanical and durability properties of hydrated lime-pozzolan mixtures, which gave rise...
This work studies the possibility of using geopolymer materials to enhance the mechanical and durability properties of hydrated lime-pozzolan mixtures, which gave rise to the so-called "hybrid systems". Two different waste types were used as pozzolan in the lime-pozzolan system: rice husk ash (RHA) and spent fluid catalytic cracking (FCC). The geopolymer fabricated with FCC was activated with commercial reagents (NaOH and NaSiO), and also with alternative sources of silica to obtain a lower carbon footprint in these mixtures. The alternative silica sources were RHA and residual diatomaceous earth (RDE) from the beer industry. The geopolymer mixture substituted the lime-pozzolan mixture for 30% replacement in weight. The hybrid systems showed better mechanical strengths for the short and medium curing ages in relation to the lime-pozzolan mixtures. Thermogravimetric analyses were performed to characterise the types of products formed in these mixtures. In the durability studies, hybrid systems better performed in freeze-thaw cycles and obtained lower capillarity water absorption values.
PubMed: 35454428
DOI: 10.3390/ma15082736 -
Molecules (Basel, Switzerland) Mar 2024In this work, diatomaceous earth (Diat) was explored as filler for polycaprolactone (PCL) to obtain composite green materials with promising viscoelastic and thermal...
In this work, diatomaceous earth (Diat) was explored as filler for polycaprolactone (PCL) to obtain composite green materials with promising viscoelastic and thermal properties. The composites were prepared by blending variable Diat amounts (5, 15 and 50 wt%) with a molten PCL matrix. The viscoelastic characteristics of PCL/Diat hybrids were studied by Dynamic Mechanical Analysis (DMA) under an oscillatory regime, while the thermal properties were determined by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). We detected that the presence of Diat enhances the energy storage capacity of PCL for temperatures lower than the polymer melting point. Both DMA and DSC data revealed that the PCL melting temperature is slightly affected by the Diat addition, while the TGA results showed that the thermal stability of the polymer can be significantly improved by mixing PCL with diatomaceous earth. Moreover, we observed that the dispersion of Diat into the matrix favors the crystallization process of PCL. Interestingly, the improvements of PCL properties (elasticity, thermal stability, and crystallinity) are proportional to the Diat concentration of the composites. These findings reflect the interfacial compatibility between PCL and diatomaceous earth. In conclusion, this study highlights that the preparation of PCL/Diat hybrids by melt blending is suitable for the development of composite materials for technological applications, including the remediation of air pollutants within museum environments.
PubMed: 38542840
DOI: 10.3390/molecules29061203 -
Scientific Reports Jan 2023In this study, injection moulding was applied to produce biocomposites consisting of polylactide (PLA) and amorphous diatomaceous earth used as a filler at different...
In this study, injection moulding was applied to produce biocomposites consisting of polylactide (PLA) and amorphous diatomaceous earth used as a filler at different concentrations. Natural wax and synthetic wax were added to improve processing properties, comparing the resulting biocomposites. The use of natural beeswax makes the composite environmentally friendly. The prepared composites contained 2.5, 5, 10 and 15% w/w filler. The test samples have been injection moulded. Rheological, mechanical, surface and other properties were assessed for the fabricated composites. The testing has shown that the use of wax additives has a significant influence on the mechanical properties (tensile strength, flexural strength, impact strength) and the hydrophilicity/hydrophobicity of composite surfaces. The addition of natural wax, especially at lower concentration, has a positive effect on the rheological properties of composites (melt flow rate, MFR), flexural modulus and impact strength. Different composite parameters are modified by different wax types so both natural and synthetic waxes, can be used interchangeably, depending on the required final material characteristics.
PubMed: 36670202
DOI: 10.1038/s41598-023-28435-0 -
Scientific Reports Nov 2019Here, we describe a simple, universal protocol for use in nucleic acid testing-based pathogen diagnostics, which requires only hand-powered sample preparation, including...
Here, we describe a simple, universal protocol for use in nucleic acid testing-based pathogen diagnostics, which requires only hand-powered sample preparation, including the processes of pathogen enrichment and nucleic acid isolation. The protocol uses low-cost amine-functionalized diatomaceous earth with a 1-μm Teflon filter as a reaction matrix in both stages of the process, using homobifunctional imidoesters. Using a simple syringe as a pump, the capture efficiency for a large sample volume (<50 mL) was enhanced by up to 98.3%, and the detection limit was 1 CFU/mL, 100-fold better than that of common commercial nucleic acid isolation kit. This protocol can also be combined with commercialized 96-well filter plates for robust sample preparation. Our proposed system is robust, simple, low-cost, universal, and rapid (taking <20 min), and it works regardless of the ambient environment and sample pretreatment, requiring no electricity or instruments. Its benefits include the simplicity of producing its components and its ease of operation, and it can be readily integrated with other assays for point-of-care diagnostics.
Topics: Aspergillus fumigatus; Brucella ovis; Diagnostic Equipment; Diatomaceous Earth; Equipment Design; Escherichia coli; Humans; Limit of Detection; Molecular Diagnostic Techniques; Nucleic Acids; Point-of-Care Systems; Real-Time Polymerase Chain Reaction; Salmonella enterica
PubMed: 31705044
DOI: 10.1038/s41598-019-52922-y -
Insects Oct 2023Over the past two decades, there has been a worldwide resurgence in the bed bugs L. and (F.). This is primarily due to insecticide resistance, making bed bug...
Over the past two decades, there has been a worldwide resurgence in the bed bugs L. and (F.). This is primarily due to insecticide resistance, making bed bug management and eradication challenging and expensive. To address the need for more affordable control solutions, "lethal harborages" were explored. Cardboard squares were treated using insecticidal dusts at different dosage levels, including silica dioxide, diatomaceous earth, deltamethrin, permethrin, and fipronil. Two strains of , one susceptible and one resistant, were allowed to enter the treated harborages, and mortality rates were recorded daily. The silica dioxide products proved to be the most efficacious, consistently achieving 100% mortality between 14-17 d at the highest dose. An artificial environment trial using the "new ChinChex" formulation of silica dioxide resulted in the complete elimination of bed bugs in the treated harborages within 21 d. These findings suggest that lethal harborages, especially those impregnated with silica dioxide, offer a cost-effective solution that could be incorporated into broader integrated bed bug management strategies. This approach may help alleviate the burden of bed bug infestations in economically disadvantaged communities.
PubMed: 37887826
DOI: 10.3390/insects14100814 -
ACS Omega May 2023Optofluidic sensors have accelerated the growth of smart sensor platforms with improved sensitivity, reliability, and innovation. In this article, we report the...
Optofluidic sensors have accelerated the growth of smart sensor platforms with improved sensitivity, reliability, and innovation. In this article, we report the integration of a surface-enhanced Raman scattering (SERS) material consisting of silver nanoparticle-decorated diatomaceous earth (AgNPs-DE) with a flow-through microfluidic device, building up a hierarchical structured micro-total analysis system (μ-TAS) capable of achieving part-per-quadrillion (ppq)-level sensitivity. By the synergic integration of millimeter-scale microfluidic devices and porous laboratory filter paper with a micrometer-sized crosslinked cellulosic network that carries SERS-active AgNPs-DE, which possesses submicron to nanometer regimes of photonic crystals and plasmonic nanostructures, we achieved enhanced mass-transfer efficiency and unprecedented detection sensitivity. In our experiment, fentanyl as the testing analyte at different concentrations was measured using a portable Raman spectrometer. The limit of detection (LOD) was estimated to be 10 ppq from a small detection volume of 10 mL with an ultrafast time of sensing (TOS) of 3 min. To attain comparable signals, the traditional soaking method took more than 90 min to detect 10 part-per-trillion fentanyl from a 10 mL sample. Compared with existing SERS sensing results of fentanyl, the limit-defying μ-TAS reduced the LOD-TOS product by almost 4 orders of magnitude, which represents a new stage of ultrafast sensing of extremely low concentration analytes.
PubMed: 37214736
DOI: 10.1021/acsomega.3c01519 -
Multi-Sample Preparation Assay for Isolation of Nucleic Acids Using Bio-Silica with Syringe Filters.Micromachines Aug 2020The spin-column system for the isolation of nucleic acids (NAs) from multiple samples presents the inconvenience of repeated experimentation, time-consumption, and the...
The spin-column system for the isolation of nucleic acids (NAs) from multiple samples presents the inconvenience of repeated experimentation, time-consumption, and the risk of contamination in the process of the spin-column exchange. Herein, we propose a convenient and universal assay that can be used to diagnose multiple pathogens using a multi-sample preparation assay. The multi-sample preparation assay combines a 96-well filter/membrane plate, a bio-micromaterial lattice-like micro amine-functional diatomaceous earth (D-APDMS), and homobifunctional imidoesters (HI) for the processing of pathogen enrichment and extraction for multiple samples simultaneously. The purity and quantity of the extracted NAs from pathogens ( and ) using the proposed assay is superior to that of the commercialized spin-column kit. The assay also does not require the replacement of several collection tubes during the reaction processing. For the multi-sample testing, we used as many as six samples simultaneously with the proposed assay. This assay can simultaneously separate up to 96 NAs from one plate, and the use of multichannel pipettes allows faster and simpler experimentation. Therefore, we believe it is a convenient and easy process, and can be easily integrated with other detection methods for clinical diagnostics.
PubMed: 32872601
DOI: 10.3390/mi11090823 -
Biomolecules Aug 2023Sand flies (Diptera: Psychodidae) serve as vectors for transmitting protozoan parasites, spp., that cause the disease called leishmaniasis. The main approach to...
Sand flies (Diptera: Psychodidae) serve as vectors for transmitting protozoan parasites, spp., that cause the disease called leishmaniasis. The main approach to controlling sand flies is the use of chemical insecticides. The discovery of alternative methods for their control is needed because of potential health risks of chemical insecticides and development of sand fly resistance to these pesticides. The biomineral produced by diatoms (diatomaceous earth, DE; Celite) and a volcanic glass bio-mimic (Imergard) have been shown by our group to be efficacious against mosquitoes, filth flies, and ticks but never studied for the control of sand flies. In a modified World Health Organization cone test, 50% of adult sand flies at 29 ± 1 °C, 55 ± 5% RH, and 12:12 LD, when exposed to Imergard and Celite, were dead in 13.08 and 7.57 h, respectively. Proof of concept was established for the use of these biominerals for sand fly and leishmaniasis disease control. Using a light source as an attractant to the minerals had no significant effect on the LT, the time to 50% mortality. The LT at a higher relative humidity of 70 ± 5% increased to 20.91 and 20.56 h for Imergard and Celite, respectively, suggesting their mode of action was dehydration. Scanning electron microscopy of dead sand flies showed high coating levels of Celite only on the sides of the thorax and on the tarsi, suggesting an alternative mode of action for mechanical insecticides.
Topics: Animals; Diatomaceous Earth; Insecticides; Leishmania; Minerals; Parasites; Psychodidae
PubMed: 37627300
DOI: 10.3390/biom13081235 -
Journal of Applied Biomaterials &... 2020The doping of silicon (Si) has been proved to improve the bioactivity of Ca-P ceramics. In light of this thinking, in the present study, Ca-P coatings with LaO by...
The doping of silicon (Si) has been proved to improve the bioactivity of Ca-P ceramics. In light of this thinking, in the present study, Ca-P coatings with LaO by addition of 10 wt% SiO and 10 wt% diatomaceous earth (DE) were fabricated by laser cladding on Ti6Al4V, respectively. Coating doped without Si was also fabricated as the comparison group for the experiment. The effect of two different Si sources on the surface morphology, microstructure, microhardness, and bioactivity was systematically studied. The experimental results show that the Si-doped coating is of rough surface morphology, and the addition of DE significantly reduces the number of cracks and improves the microhardness. The X-ray diffraction results reveal that the amount of bioactive phase tricalcium-phosphate (TCP) and hydroxyapatite (HA) reaches maximum in the DE-doped coating. After soaking in simulated body fluid (SBF), the precipitate of bone-like apatite in the DE-doped coating is significantly higher than that of the other coatings.
Topics: Alloys; Body Fluids; Calcium Phosphates; Ceramics; Coated Materials, Biocompatible; Durapatite; Hardness; Lanthanum; Lasers; Oxides; Silicon Dioxide; Surface Properties; Titanium; X-Ray Diffraction
PubMed: 32552186
DOI: 10.1177/2280800020917322