Nitrogen Adsorption-desorption Measurements Research Articles

One-Pot Preparation of Mixed-Mode Reversed-Phase Anion-Exchange Silica Sorbent and its Application in the Detection of Cyclopiazonic Acid in Feeds and Agricultural Products.

A novel co-bonded octyl and pyridine silica (OPS) sorbent was prepared and applied for the solid phase extraction (SPE) of cyclopiazonic acid (CPA, a type of mycotoxin) in feed and agricultural products for the first time. A simple mixed-ligand one-pot reaction strategy was employed for OPS sorbent preparation. Nitrogen adsorption-desorption measurements, elemental analysis (EI), thermal gravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR) analysis demonstrated the successful immobilization of octyl and quaternary ammonium groups onto the surface of silica gel. The large specific surface area, high-density functional groups, and mixed-mode anion-exchange characteristics of these silica particles made them the ideal material for the efficient extraction of CPA. Additionally, the OPS sorbents displayed excellent batch-to-batch reproducibility, satisfactory reusability, and low cost. The SPE parameters were optimized to explore the ionic and hydrophobic interactions between CPA and the functional groups, and the ultra-high performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UPLC-MS/MS) parameters were optimized to obtain a desirable extraction efficiency and high sensitivity to CPA. Meanwhile, the OPS sorbent presented a satisfactory extraction selectivity and low matrix effect. Under the optimized conditions, our developed CPA detection method was used to determine CPA level in rice, wheat flour, corn flour, peanut, and feed samples, exhibiting a lower detection limit, better linearity, higher sensitivity, and satisfactory extraction recovery rate than previously reported methods. Therefore, our method can be preferentially used as a method for the detection of CPA in agricultural products and feeds.

Studies on the Process of Basic Dyes Adsorption on Uniform Spherical Carbons.

The influence of carbon pore structure on the sorption process of selected cationic dyes has been investigated. The structure and surface of carbonaceous materials have been characterized basing on various techniques: scanning electron microscopy, low temperature nitrogen adsorption-desorption measurements, X-ray photoelectron spectroscopy and thermal analysis combined with identification of gaseous products. The kinetic and equilibrium adsorption measurements of Basic Violet 3, Basic Red 1 and Basic Blue 9 from aqueous media were performed. The studied carbons seem to be promising adsorbents towards dyes, taking into account the easy-to-use uniform spherical form of the granules and a complex type of porosity with micro-, meso- and macropores appropriate for large molecule adsorption.

Ionic Liquid Modified Polymer Gel for Arsenic Speciation.

A new ionic liquid modified polymer gel containing methylimidazolium groups (poly(MIA)) is proposed as a sorbent for the separation and enrichment of trace inorganic and organic arsenic species in surface waters. The poly(MIA) was synthesized by chemical modification of polymeric precursor using post-polymerization modification of poly(glycidyl methacrylate-co-trimethylolpropane trimethacrylate). The composition, structure, morphology, and surface properties of the prepared particles were characterized using elemental analysis, Fourier transform infrared spectroscopy, scanning electron microscopy, and nitrogen adsorption-desorption measurements. Optimization experiments showed that at pH 8, monomethylarsonic acid (MMAs), dimethylarsinic acid (DMAs), and As(V) were completely retained on the poly(MIA), while the sorption of As(III) was insignificant. The desorption experiments revealed that due to the weaker binding of organic arsenic species, selective elution with 1 mol/L acetic acid for MMAs + DMAs, followed by elution with 2 mol/L hydrochloric acid for As(V), ensured their quantitative separation. The adsorption kinetic and mechanism were defined. The analytical procedure for As(III), As(V), MMAs, and DMAs determination in surface waters was developed and validated through the analysis of certified reference material.

Feroxyhyte - from synthesis and characterization to application.

Feroxyhyte (δ-FeOOH) was synthesized and characterized using X-ray diffractometry (XRD), simultaneous thermal analysis (STA), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDS), and low-temperature nitrogen adsorption-desorption measurements. Its potential application as adsorbent of an anionic and cationic dyes such as C.I. Acid Violet 1 (AV1) and C.I. Basic Blue 3 (BB3) was investigated by determining the adsorption capacities based on the Langmuir (36.6 mg/g for AV1 and 187 mg/g for BB3), Freundlich and Dubinin-Radushkevich isotherm models. Adsorption of AV1 and BB3 by δ-FeOOH drops with the presence of additives such as cationic and anionic surfactants (CTAB, SDS) and ionic polymers (PAA, PEI). The surface and electrokinetic properties of examined suspensions were also described. They include determination of the solid surface charge density and the zeta potential, as well as values of point of zero charge and isoelectric point of feroxyhyte particles without and with adsorbed layers of organic substances. Their analysis made possible to propose the most probable structure of electrical double layer formed at the iron mineral/aqueous solution interface.

Dendritic bifunctional nanotraps inside SBA‐15 for highly efficient removal of selected nonsteroidal anti‐inflammatory drugs from wastewater

AbstractLarge‐pore mesoporous SBA‐15 materials were functionalized with dendritic bifunctional ligands to achieve efficient adsorption of nonsteroidal anti‐inflammatory drugs (NSAIDs) in aqueous solution mainly through a combination of anion‐exchange ability of quaternary ammonium cations and π‐π interaction capability of oxygen activated phenyls. The synthesis of such a dendritic ligand starts from propylamine on SBA‐15 followed by consecutive amine‐epoxy reactions with resorcinol diglycidyl ether (RDGE) and methylamine, and then amination of terminal epoxy with trimethylamine. The results from Fourier‐transform infrared spectroscopy, nitrogen adsorption–desorption measurements and elemental analysis reveal that the bifunctional dendritic nanotraps have been created successfully inside the mesochannels of SBA‐15 (DNT@SBA‐15). Adsorption kinetics for NSAIDs was very rapid following a pseudo‐second‐order kinetic model, and adsorption isotherms were fitted well by the Langmuir isotherm model. Notably, DNT@SBA‐15 demonstrated remarkably high adsorption capacities for NSAIDs, with maximum values of 1037.3 mg g−1 for ibuprofen, 821.3 mg g−1 for naproxen and 781.3 mg g−1 for diclofenac at pH 7.0. The adsorption was presumed to be governed by a dual‐interaction mechanism including electrostatic and van der Waal's interactions. This study demonstrates that the developed dendritic anion‐exchanger can be a promising material for removing NSAIDs adsorption from environmental water.

Highly stable hybrid porous polymers containing polyhedral oligomeric silsesquioxane (POSS)/Dibenzo[g,p]chrysene and Dibenzo[b,d]thiophene units for efficient Rhodamine B dye removal

In this study, we employed the Heck reaction method to synthesize three types of hybrid porous organic/inorganic polymers (HPPs) incorporating octavinylsilsesquioxane (OVS) units. Specifically, we synthesized OVS-TBN-DBTH, OVS-TBN-THS, and OVS-TBN-THSO2 HPPs by reacting OVS with different brominated organic compounds, namely, 2,7,10,15-tetrabromodibenzo[g,p]chrysene (TBN-Br4)/2,8-dibromodibenzo[b,d]thiophene (DBTH-Br2), TBN-Br4/2,3,7,8-tetrabromothianthrene (THS-Br4), and TBN-Br4/2,3,7,8-tetrabromothianthrene-5,5,10,10-tetraoxide (THSO2-Br4). Based on thermal analysis (TGA), the onset decomposition temperatures (Td10) for these HPPs were as follows: OVS-TBN-DBTH at 575 °C, OVS-TBN-THS at 313 °C, and OVS-TBN-THSO2 at 490 °C. Additionally, these HPPs exhibited high char yields, with values of 83, 53, and 67 wt% for OVS-TBN-DBTH, OVS-TBN-THS, and OVS-TBN-THSO2 HPPs, respectively. Furthermore, when analyzed using nitrogen adsorption–desorption measurements, both OVS-TBN-DBTH and OVS-TBN-THSO2 HPPs demonstrated impressive specific surface areas (SBET) of up to 380 m2/g. In addition, the OVS-TBN-DBTH and OVS-TBN-THSO2 HPPs provide an adsorption capacity of 70.62 and 77.1 mg g−1 (qmax from Langmuir isothermal Mode) toward RhB dyestuff at room temperature. In this adsorption system, after calculation, the OVS-TBN-THS HPP could be inferred that the adsorption is a pseudo-first order adsorption model. The OVS-TBN-THS HPP and OVS-TBN-THSO2 HPP in the pseudo-secondary order model have a better representation of the adsorption system for rhodamine B. This study introduces an innovative method for developing HPPs as adsorbents for water treatment and purification.

Toward clima-resilient ultra-high performance concrete (UHPC): A survey on high-strength mortars engineered with extra-low dosage graphene-based materials (GBMs)

Latest advances showed that ultra-high performance concrete (UHPC) holds the potential to meet the criteria of future civil infrastructures. Several nanofillers (NFs) proved to enhance the performance of UHPC in terms of economic and environmental sustainability and even assigning novel features. Presently, this promising approach is still in its early stage. In this perspective, mortars based on Portland cement CEM I 52.5 N were engineered with extra-low dosage (0.01% by weight of cement) graphene nanoplatelets (GNPs) or nanographite (nG). An acrylic superplasticizer for high-strength concrete was used as additive. Fresh properties of the cementitious admixtures were characterized by viscosity measurements, flow table and bleeding tests. Prismatic specimens were hardened in water at room temperature for 28 days. Microstructure was observed by Scanning Electron Microscopy, the pore structure and specific surface area (SSA) investigated by Mercury Intrusion Porosimetry (MIP) and nitrogen adsorption-desorption measurements, thermal behavior studied by thermogravimetry, and mechanical strength evaluated by compression and bending tests. Electrical resistivity was determined by Electrochemical Impedance Spectroscopy (EIS). Both 2D-NFs induced a slight lubricant effect that did not significantly affect neither workability nor bleeding. GNPs do not appreciably impact on the mechanical properties of the hardened nano-engineered materials, a decay of bending strength was observed only for nG-loaded samples. The positive impact of the extra-low dosage GNPs on the hardened mortars was clearly detected by MIP and EIS in terms of reduced porosity (−31%), improved bulk density (+5.7%), pore refining (median and average pore diameter −35% and −9%, respectively), increased resistivity (+97%) and lowered predicted intrinsic permeability (−52%). In the same experimental condition, nG-engineered mortars suffered from uneven dispersion that led to increased porosity and pore coarsening.

Influence of thermal and acidic treatments on the morphology of a natural kaolinitic clay mineral

In this work, a natural kaolinitic clay mineral from Kribi in Cameroon is modified by thermal and acidic treatments. The influence of these treatments on the physicochemical properties of the clays is studied using X-ray diffraction, Fourier transform infrared spectroscopy, nitrogen adsorption–desorption measurements, scanning electron microscopy, inductively coupled plasma–atomic emission spectroscopy and thermal analysis. Three calcination temperatures are explored: 600, 700 and 800 °C. The XRD pattern of the untreated clay showed that the natural clay mineral was mostly composed of kaolinite. Calcination at high temperatures allowed the amorphization of the natural kaolinitic clay mineral to obtain metakaolinite. This heat treatment of the natural clay mineral produced disintegration by rupture of the strong hydrogen bonds between the layers of the clay mineral. Heat treatment did not increase the specific surface area of the clay, which stayed around 20-30 m2/g. The acid treatment produced a high material texture modification giving microporous materials with a large surface area up to 315 m2/g with the sample previously calcined at 800 °C. The microporosity and mesoporosity increase is greater when the clay is calcined at high temperature. The morphology of the samples observed by SEM are modified by the acidic treatment. The initial two-dimensional stacking of particles evolves towards a narrower three-dimensional porous structure. These treatments open the way to produce highly porous clay materials that could be used as adsorbent materials for pollutant removal from water.

Effect of nano-silica extracted from two different plant sources on survival and development of Phthorimaea opercullela (Zeller) larvae

Summary The study examined the effect of nano-silica extracted from two different plant sources on the survival and development of the potato tuber moth, Phthorimaea opercullela. The silica powder was derived from two different agricultural byproducts, olive stones and corncobs. Characterization by X-ray diffraction revealed that the extracted powder has an amorphous silica phase. The nitrogen adsorption-desorption measurements revealed that both extracted and treated silica have mesoporous structure, with a specific surface area of around 300 m2/g and 270 m2/g for the silica derived from olive stones and corncobs, respectively. The silica nanoparticles (SiO2 NPs) prepared from the silica derived from olive stοnes showed higher larvae mortality, pupae weight, and larval and pupal developmental time, compared to the silica derived from corncombs. The results show that the nano-silica derived from agriculture byproducts can be as effective as the synthetic insecticide (deltamethrin) utilized in control of the potato tuber moth, with lower environmental impact in terms of preventing pesticide residue accumulation. In addition, the efficiency of SiO2 NPs applications depends on the source of the silica nanoparticles and the applied concentration to achieve the optimum results for the pest control.

Construction of polydopamine-polyethyleneimine composite coating on the surface of poly (styrene–divinylbenzene) microspheres followed by quaternization for preparation of anion exchangers

As a mussel-inspired material, dopamine (DA) is widely applied for the surface modification of various bulk materials based on its self-polymerization properties. Whereas, polydopamine (PDA) modified poly (styrene–divinylbenzene) (PS-DVB) microsphere is still hard to be quaternized under mild conditions. In this work, polyethyleneimine (PEI) is selected as the comonomer to participate in the crosslinking with PDA to form PDA-PEI composite coating on the surface of PS-DVB microsphere. Then, PS-DVB@PDA-PEI microsphere is further quaternized utilizing PDA-PEI coating as the secondary functionalized platform to prepare anion exchanger. The anion exchanger is characterized by scanning electron microscope, fourier transform infrared spectroscopy, nitrogen adsorption–desorption measurement, X-ray photoelectron spectroscopy, elemental analysis, thermogravimetric analysis. The chromatographic performance is evaluated by separating seven conventional anions, organic weak acids, et. al. The results indicate that PDA-PEI shows higher reactivity than PDA due to the present of abundant amine groups. The introduce of PDA-PEI coating makes PS-DVB microspheres can be quaternized under mild conditions. The strategy presented here is very suitable for the preparation of anion exchangers.

Catalytic Ozonation of Pesticide Wastewater by Using MCM-41 and ZSM-5/MCM-41 as Catalysts

In the present study, two catalysts, MCM-41 and ZSM-5/MCM-41, were prepared by the hydrothermal synthesis method and their catalytic ozonation performances on pesticide wastewater were investigated. MCM-41 and ZSM-5/MCM-41 were proved to be a mesoporous structure and a micro-mesoporous structure, respectively, by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption-desorption measurements. The experimental results indicated that the chemical oxygen demand (COD) removal rate increased from 57.46% without catalysts to 79.35% and 87.56%, respectively, in the presence of MCM-41 and ZSM-5/MCM-41 after 100 min of catalytic ozonation. The catalytic activity of ZSM-5/MCM-41 was found to be greater than that of MCM-41. OH· played an important role in the catalytic ozonation, which was verified by the tert-butanol test. The catalysts had highest activity at pH of 7, and both higher and lower pH values reduced the catalytic ozonation. The optimal ozone dosage was found to be 22.0 mg L−1 min−1 for the COD removal of the pesticide wastewater. The catalysts could be reused five times without significant loss of the catalytic activity, suggesting that the catalysts could be promising catalysts for the catalytic ozonation of the pesticide wastewater.

Hydroformylation of Alkenes over Phosphorous-Free Rhodium Supported on N-Doped Silica

A new phosphorous-free rhodium supported on a nitrogen-doped silica was successfully used as a catalyst for the hydroformylation of alkenes. The obtained material and the catalyst were characterized by XRD, XPS, FTIR, SEM, TEM, ICP AES, and low-temperature nitrogen adsorption–desorption measurements. The catalytic performance was studied by the example of the hydroformylation of octene-1 at temperatures of 80–140 °C and a pressure of 5.0 MPa. The catalyst provided a 99% conversion of 1-octene with a 98% yield of aldehydes and showed a good conversion of styrene and cyclohexene. The catalyst can be repeatedly used in ten consecutive cycles, with its activity remaining constant.

Porous activated carbon materials from Triphala seed stones for high-performance supercapacitor applications

Porous activated carbon materials derived from biomass could be the suitable materials for high-rate performance electrochemical supercapacitors as it exhibits high surface area due to well-defined pore structure. Here, we report the novel porous activated carbon from Triphala seed stones by chemical activation with zinc chloride at different carbonization temperature (400-700 °C) under the nitrogen gas atmosphere. The activated carbon was characterized by Fourier transform-infrared (FTIR) spectroscopy, Raman scattering and scanning electron microscopy (SEM). Nitrogen adsorption-desorption measurements was used to study the surface properties (effective surface areas, pore volumes and pore size distributions). The electrochemical measurements were performed in an aqueous 1 M sulphuric acid (H2SO4) solution in a three-electrode cell set up. Triphala seed stones-derived porous carbon materials with well-defined micro- and mesopores exhibit high specific surface area ranges from 878.7 to 1233.3 m2 g-1 and total pore volume ranges from 0.439 to 0.626 cm3 g-1. The specific capacitance obtained by electrochemical measurement experiment was 208.7 F g-1 at 1 A g-1. These results indicate that the prepared nanoporous activated carbon material from Triphala seed stones would have significant possibility as supercapacitor electrode material for high-energy-storage supercapacitor applications.

Nanostructured films formed on Zn during anodic oxidation in different carbonate-based electrolytes

Electrochemical generation of nanowire arrays by one-step anodic oxidation of Zn in carbonate-based electrolytes of different pH values is described. Zn foil was anodized in a mixture containing 5 mM Na2CO3 and 5 mM NaHCO3, as well as in pure Na2CO3 and NaHCO3 (both 10 mM). The morphology of anodic films was verified by FE-SEM. A special emphasis was put on the analysis of the composition of as-received nanomaterials by various techniques including XRD, XPS, UV–Vis, and Raman spectroscopy. Contrary to previous reports, we confirmed that the unknown phase of zinc carbonate with a formula of ZnCO3·H2O or Zn(HCO3)(OH) is formed at the Zn surface during anodization. The formation of ZnO resulting in more evident electrode passivation was also observed in the electrolytes containing sodium carbonates. The changes occurring during the thermal treatment of as-received materials were described based on TG, XPS, XRD, Raman, and nitrogen adsorption-desorption measurements. It was verified that, except for a several-fold increase in the active surface area, no significant changes in the wire-like morphology of the anodically generated product occur during its thermal conversion to ZnO. Finally, no noticeable differences in the photoelectrochemical performance of ZnO nanostructures formed in different electrolytes were observed.

Dissolution kinetics studies of kaolin ore as raw material for mesoporous silica by acid leaching

ABSTRACT The high demand for nanoporous silica materials makes it worthwhile to further explore new, cheap and environmentally friendly resources. In this study, the selective acid dissolution of an indigenous kaolin ore after thermal activation for the preparation of mesoporous silica nanoparticles was reported. Experimental parameters (acid concentration, liquid/solid ratio and temperature) were optimised and resultant solid was characterised by X-ray diffraction; scanning and transmission electron microscopy and nitrogen adsorption–desorption measurements. The products were found to be nanoporous with pore sizes of 0.402 and 0.129 cm3 g–1, with specific surface areas of 45.23 and 16.89 m2 g–1, respectively. The pore development follows the Avrami model with parameter model n values of 0.80 and 0.63, and calculated apparent activation energies of 7.22 and 22.81 kJ mol–1 for hydrochloric and sulphuric acid respectively, suggesting that the leaching activity is controlled by diffusion processes. The products as characterised demonstrated the vast potential of kaolinite in the development of mesopore materials for diverse industrial applications.

Development of Bi2O3/MoSe2 mixed nanostructures for photocatalytic degradation of methylene blue dye

Herein, we demonstrate the sample and low coast hydrothermal synthesis of a nanocomposite of Bi2O3/MoSe2 for hybrid photocatalyst. The structure of as-synthesized samples was characterized by using several techniques, including XRD spectroscopy, Raman spectroscopy, XPS, SEM, BET, and UV-visible absorption spectroscopy. The nitrogen adsorption–desorption measurements show that the samples have a mesoporous texture with slits like pores. The Bi2O3/MoSe2 nanocomposite had BET surface areas of 36.439 m2/g, which were more than those of Bi2O3 (18.342 m2/g) and MoSe2 (12.923 m2/g). Under visible illumination, the photocatalytic activities of pure samples ( Bi2O3 and MoSe2) and the hybrid Bi2O3/MoSe2 sample for the disintegration of methylene blue were assessed. The results show that the Bi2O3/MoSe2 sample showed the highest photocatalytic degradation efficiency (i.e. 96.5% after an exposure time of 80 min). The increased photocatalytic activity is due to the mixed sample's high crystallinity and surface area, as well as the small particle size.

Study of the catalytic properties of MgNi(Cu)Al LDH in the one-pot cascade oxidation-Knoevenagel condensation reaction

In this work, the structural and bifunctional catalytic properties of MgNi(Cu)Al layered double hydroxides (LDH) with different molar ratios between the cations were studied. The LDH materials were prepared by co-precipitation and were characterized using X-ray fluorescence (XRF), X-Ray diffraction (XRD), diffuse reflectance infrared Fourier-transform spectroscopy (DRIFT), diffuse reflectance ultraviolet-visible spectroscopy (DR-UV-VIS), scanning electron microscopy (SEM), nitrogen adsorption-desorption and acidity-basicity measurements. They were tested in a one-pot cascade oxidation-Knoevenagel condensation reaction used to synthesize 2-Benzoyl-3-phenylprop-2-enenitrile also known as 2-Benzoyl-3-phenylacrylonitrile (BPA). This involved the benzyl alcohol (BnOH) oxidation under an oxygen atmosphere followed by the Knoevenagel condensation of benzaldehyde with 3-oxo-3-phenylpropanenitrile also known as benzoyl acetonitrile (BzACN). Three different non-polar solvents, i.e., toluene, benzene and 1,3,5-trimethylbenzene (mesitylene), were used as reaction media. For the LDH catalysts containing both nickel and copper, the alcohol conversion and BPA yield increased with Ni/Cu molar ratio. The acid-base properties of the solids and the nature of the solvent strongly influence the reaction performance.

Influence of Rapid Heat Treatment on the Photocatalytic Activity and Stability of Strontium Titanates against a Broad Range of Pollutants

Strontium titanate (STO) photocatalysts were prepared via a slightly modified Pechini sol–gel method. A unique rapid calcination technique with a short exposure time was used to obtain crystalline products. The samples were characterized by X-ray diffractometry, scanning electron microscopy, diffuse reflectance spectroscopy, infrared spectroscopy, nitrogen adsorption–desorption measurements, and X-ray photoelectron spectroscopy. Their photocatalytic activity was evaluated by the photocatalytic oxidation of phenol, oxalic acid, and chlorophenol under UV light irradiation using commercial STO as a reference. These pollutants, together with glucose and propanol, were used to investigate the stability of the samples against various functional groups. All our samples exhibited higher photocatalytic activity than the commercial STO reference. With increasing calcination temperature, the crystallinity and primary crystallite sizes increased while the band gaps and specific surface areas decreased. The photocatalytic activity of the most efficient sample was explained by the presence of SrCO3 on its surface. The STO catalysts were highly stable as they largely retained their crystalline composition after exposure to chemicals with different functional groups. Finally, we compared the costs associated with the unique calcination technique with a more conventional one and found that our method is ~35% more cost-effective.

Efficacy of Olive Stones and Corncobs Crystalline Silica Nanoparticles (SiO2, NPs) Treatments on Potato Tuber Moths (Phthorimaea Operculella)

Morphological and microstructural properties of silica (SiO2) are essential factors that need to be considered during the experimental applications. In this report, SiO2 nanoparticles (NPs) have been prepared at different concentrations from SiO2 powder derived from olive stones and corncobs by an alkali leaching extraction method. Thermal treatment has been used to modify the morphological and microstructural properties of the extracted SiO2. X-ray diffraction (XRD) shows that the extracted amorphous SiO2 has been transformed into a crystalline phase after the thermal treatment. Nitrogen adsorption–desorption measurements revealed significant reduction in both the specific surface area (SABET) and the total pores volume (Vtotal) of the derived SiO2 samples after the thermal treatment. The acquired thermal treatment properties of SiO2 found to have high impacts on the influence of the SiO2 NPs on the survival and development of larvae and pupae of P. opercullela. SiO2 NPs prepared from the crystalline silica samples exhibited less efficiency on suppressing potato tuber moth comparing to SiO2 NPs of the amorphous silica powders. Varied effects on biological parameters including larvae mortality, pupae weight, larval and pupal development time, fecundity and fertility are also linked to the SiO2 NPs source type and showed concentration depending manner effects. SiO2 NPs are conditionally effective as an alternative pesticide against P. opercullela, based on their sources, mesoporous structures and concentrations.

Structure of Y0.75La0.25PO4·0.67H2O rhabdophane nanoparticles synthesized by the hydrothermal microwave method

Nanopowders with a rhabdophane structure of nominal composition Y0.75La0.25PO4·0.67H2O were obtained by hydrothermal-microwave synthesis. The monoclinic structure of rhabdophane was refined by the Rietveld method within the C2 (5) space group. The nanopowders were studied by X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron microdiffraction (selected area electron diffraction, SAED), small angle X-ray scattering (SAXS), thermal analysis, low-temperature nitrogen adsorption-desorption measurements for analysis of surface area and porosity (ASAP) and pycnometric density measurements. These methods showed the formation of rod-like single-crystal rhabdophane nanoparticles with isolated pores inside the nanoparticles. To describe the formation of such nanoparticles, a mechanism of coherent-accommodative intergrowth of nanoscale clusters with rhabdophane structure is proposed.