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Graphical abstract Lactose fatty acid ester was synthesized using commercially available aluminosilicate zeolite as Lewis acid catalyst in different organic solvents. Reactions were done at 55 °C using pure or raw lactose with lauric acid to synthesize lactose monolaurate as biosurfactant without using lipase. Highlights • A commercial zeolite was used as a catalyst for esterification of lactose with lauric acid. • Pure and raw lactose derived from whey were used in esterification. • Products were easily purified using a solvent extraction method. • Products showed low surface and interfacial tensions compared to industrial surfactants. Abstract Sugar-based biosurfactants are safer and healthier alternatives to synthetic surfactants especially for use in the food industry. In this work, biosurfactants were synthesized via the esterification of lactose with lauric acid in different organic solvents without using lipase or other enzymes. Commercial aluminosilicate zeolite was used as a catalyst. Conversions of up to 92% were obtained for pure lactose and 38% for raw lactose from whey. Surface-active properties including surface tension, interfacial tension, and contact angle were measured. All samples showed surface tensions lower than sodium dodecyl sulfate, SDS (19.59–36.57 mN/m compared to 38.8 mN/m for SDS) and interfacial tensions comparable with it (9.47–12.18 mN/m compared to 4.77 mN/m for SDS). Results showed that aluminosilicate zeolites can be used for the synthesis of lactose esters, which have potential applications as biosurfactants for the food industry featuring low surface and interfacial tensions. [ABSTRACT FROM AUTHOR]

Commercial aluminosilicate proppant particles have been coated with Ca-Si oxides, with the aim to provide an in-situ increase in the angularity (decrease in Krumbein roundness value) to facilitate their immobilization. Ca-Si oxide systems have been synthesized via sol-gel, cured, and sintered at 1200 °C using (a) CaCO 3 , (b) CaCO 3 + orthosilicic acid (Si(OH) 4 , SA), and (c) CaCO 3 + fused silica (SiO 2 , FS). When the proppant is cured in the presence of CaCO 3 and silicic acid the coatings undergo a significant compositional change, while sintering results in the conversion of the cured samples to ceramic agglomerates with the desired “popcorn” shapes. The best results are obtained in the presence of Si reagents, and hydration of these sintered proppants allows for a distinct increase in the angularity, which is the desired transformation to allow the proppant to be locked-in-place once located in the reservoir. The samples have been characterized at each stages of preparation by scanning electron microscopy (SEM) with associated energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and infrared (IR) spectroscopy. [ABSTRACT FROM AUTHOR]

Dynamic mechanical behavior of vertically and horizontally built AlSi10Mg_200C alloy, manufactured by SLM technique was investigated at high strain rates ranging from 150 s −1 to 1600 s −1 using Split Hopkinson Pressure Bar. Texture of the deformed samples was measured using X-ray diffraction technique. The yield strength, peak flow stress, and ductility increased in all samples with increase of strain rate. It was concluded that deformation at high strain rates had no effect on the texture components of vertical samples. However, texture transition was observed in horizontal samples, in which strong Goss and Cube components were developed at strain rate of 1600 s −1 . The texture transition and dynamic mechanical behavior of the samples were briefly discussed. [ABSTRACT FROM AUTHOR]

The present study concerns the preparation, characterization and testing of an inorganic ion exchanger Aluminum Silicate Modified Magnesia (ASMM). The ASMM composite was prepared using sol-gel technique and characterized by XRD, XRF, FTIR, TGA, DTA, SEM and surface area analysis. The capability of the prepared composite for the removal of ( Cs + , Co 2 + and Eu 3 + ) from aqueous solution was evaluated. Sorption studies were carried out taking into account important parameters such as (pH, initial concentration, contact time and temperature). Kinetic and isotherm models were applied to the prepared composite, kinetic data is well fitted with pseudo-second order kinetic model, Dubinin-Radushkevich isotherm model indicates that sorption was controlled by chemisorption process. The removal efficiency found to be 80% for Cs + , 90% for Co 2 + and 95% for Eu 3 + . [ABSTRACT FROM AUTHOR]

This study investigates the pore structure and shrinkage behavior of metakaolin-based geopolymer pastes and mortars containing 0–30% fly ash. Fly ash substitution decreases average reactivity of the solid precursors, resulting in a lower reaction rate and accompanying longer reaction time. Composition of the sodium aluminosilicate (N-A-S-H) gel formed in the geopolymers has been changed, and the continued reaction after hardening of the pastes generates a more compact binding gel phase with lower Al/Si ratio. Refinement of the pore structure entails a higher capillary tension developed in the binders to increase the autogenous shrinkage, but also restricts the water evaporation from the pore networks, resulting in a decreased drying shrinkage. The geopolymer mortars provide higher compressive strength and lower total shrinkage when compared with the pastes. [ABSTRACT FROM AUTHOR]

Two binary geopolymers were prepared from the mixture of low-calcium bayer red mud and kaolinite-based coal gangue. The geopolymers were synthesized using two affordable and feasible methods mainly differed in preactivation and curing processes. The influence of the mix ratio of raw material and alkali activator on the compressive strength properties of two series geopolymers was investigated, and the optimal specimens of which were then determined. Furthermore, a comparative research on the mineral composition, crystal structure and microstructure of the superior geopolymers was performed through XRD, TG-DTA, and SEM-EDXS. Results revealed that GR8G2 was the optimum sample for the series geopolymer I and CR9G1 for geopolymer II. The compressive strength of all samples ranges from 15.05 to 30.25 MPa, the geopolymer synthesized from mechanical grinding preactivation displayed better developed strength. Mineral composition and microstructure studies indicated that both the final products are consist of amorphous silica-alumina-based geopolymer gels and some impurity fillers. This study showed that the two geopolymer synthesis methods for red mud and coal gangue were feasible, and the geopolymers may be applied as a new building material. Further studies are necessary to determine the optimal application parameters. [ABSTRACT FROM AUTHOR]

We design and fabricate a silica optical fiber doped with yttrium aluminosilicate (YAS, Y 2 O 3 –Al 2 O 3 –SiO 2 ) nanoparticles in the core. The optical fiber is drawn directly from a silica tube with YAG (Y 3 Al 5 O 12 ) ceramics and silica powders (the molar ratio 1:18) in the core at the temperature of ∼1950 °C. The YAS nanoparticles are formed during the optical fiber drawing process. Supercontinuum (SC) generation in the optical fiber is investigated at different pump wavelength. At the pump wavelength of ∼1750 nm which is in the deep anomalous dispersion region, SC spectrum evolution is mainly due to multiple solitons and dispersive waves (DWs), and three pairs of multiple optical solitons and DWs are observed. When the pump wavelength shifts to ∼1500 nm which is close to the zero-dispersion wavelength (ZDW), flattened SC spectrum with ±7 dB uniformity is obtained at the wavelength region of ∼990–1980 nm, and only one obvious soliton and DW are observed. At the pump wavelength of ∼1100 nm, a narrow SC spectrum from ∼1020 to 1180 nm is obtained in the normal dispersion region due to self-phase modulation (SPM) effect. [ABSTRACT FROM AUTHOR]