scholarly journals Microalgae Harvesting: A Review

2019 ◽  
Vol 27 (44) ◽  
pp. 129-143
Author(s):  
Alexandra Kucmanová ◽  
Kristína Gerulová
Keyword(s):  
Magnetic Particles ◽  
Precipitation Method ◽  
Synthesis Methods ◽  
Advantages And Disadvantages ◽  
Commercial Use ◽  
Microalgae Harvesting ◽  
Terrestrial Habitats ◽  
Algal Products ◽  
Co Precipitation ◽  
Surface Modified

Abstract Microalgae are photosynthetic autotrophic microscopic organisms growing in a range of aquatic and terrestrial habitats. They produce a huge complex of compounds in their surroundings which are of important use to humans. Their commercial use lies in human nutrition, animal and aquatic feed, in cosmetics products, natural pigments, pharmaceutical industry, bio-fertilizer for extracting high-value molecules, stable isotope biochemicals, and for the synthesis of antimicrobial, antiviral, antibacterial and anticancer drugs. Therefore, it is necessary to develop a simple, effective and economically advantageous method for harvesting the algal products. Magnetic separation is a simple separation process. Different synthesis methods have been used by researchers to obtain magnetic particles of varying size and shapes according to the algae to be studied. Chemical co-precipitation method has been the most commonly used method, which helps in synthesizing magnetic particles of the micro to nano range. Naked, coated and surface modified are the general types of magnetic particles used for algal harvesting with its own advantages and disadvantages.

Synthesis of Silica Modified Large-Sized Hydroxyapatite Whiskers by a Hydrothermal Co-Precipitation Method

2015 ◽  
Vol 645-646 ◽  
pp. 1339-1344 ◽  
Author(s):  
Yan Ting Yin ◽  
Qing Hua Chen ◽  
Ting Ting Yan ◽  
Qing Hua Chen
Keyword(s):  
Bone Repair ◽  
Ethanol Solution ◽  
Morphological Properties ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
New Type ◽  
Ft Ir ◽  
Co Precipitation ◽  
Surface Modified

The objective of this study was to develop a novel silica modified large-sized hydroxyapatite whiskers with improved properties for use in bone repair applications. Large-sized whiskers with a mean length of 250μm were obtained by a hydrothermal co-precipitation method at 150°C, 7.5Mpa in high-pressure reactor. Silica modified hydroxyapatite whiskers were prepared by dissolving TEOS in ethanol solution, then sintering with hydroxyapatite. The compositional and morphological properties of prepared whiskers were studied by means of x-ray diffraction (XRD), Fouier transform infrared (FT-IR), scanning electron microscopy (SEM). The results indicated the evidence of nanosilicon dioxide particles on the surface of HAP whiskers. The size of nanosilicon dioxide particles depends on dropping and stirring rate. Hence, this new type of silica modified large-sized hydroxyapatite whiskers is a valuable candidate for biomedical applications.Key words: hydroxyapatite, hydrothermal co-precipitation, surface modified, whiskers

scholarly journals Magnetically recyclable Ag/TiO2 co-decorated magnetic silica composite for photodegradation of dibutyl phthalate with fluorescent lamps

2020 ◽  
Vol 81 (4) ◽  
pp. 790-800
Author(s):  
Zhiqiang Ding ◽  
Yue Liu ◽  
Yong Fu ◽  
Feng Chen ◽  
Zhangpei Chen ◽  
...  
Keyword(s):  
Magnetic Particles ◽  
Dibutyl Phthalate ◽  
Degradation Process ◽  
Environmental Safety ◽  
Degradation Efficiency ◽  
Precipitation Method ◽  
Solution Ph ◽  
Fluorescent Lamps ◽  
Butyl Phthalate ◽  
Co Precipitation

Abstract In recent years, industrial contaminants and especially organic pollutions have been threatening both environmental safety and human health. Particularly, dibutyl phthalate (DBP) has been considered as one of the major hazardous contaminants due to its widespread production and ecological toxicities. Consequently, reliable methods toward the efficient and environmentally benign degradation of DBP in wastewater would be very desirable. To this end, a novel magnetically separable porous TiO2/Ag composite photocatalyst with magnetic Fe3O4 particles as the core was developed and successfully introduced to the photocatalytic degradation of DBP under visible irradiation with a fluorescent lamp. The presented work describes the grafting of Ag co-doped TiO2 composite on the silica-modified porous Fe3O4 magnetic particles with a simple and inexpensive chemical co-precipitation method. Through the investigation of the influencing factors including photocatalyst dosage, initial concentration of DBP, solution pH, and H2O2 content, we found that the degradation efficiency could reach 74%. The photodegradation recovery experiment showed that the degradation efficiency of this photocatalyst remained almost the same after five times of reuse. In addition, a plausible degradation process was also proposed involving the attack of active hydroxyl radicals generated from this photocatalysis system and production of the corresponding intermediates of butyl phthalate, diethyl phthalate, dipropyl phthalate, methyl benzoate, and benzoic acid.

Calcium Carbonate and Cellulose/Calcium Carbonate Composites: Synthesis, Characterization, and Biomedical Applications

2016 ◽  
Vol 875 ◽  
pp. 24-44
Author(s):  
Ming Guo Ma ◽  
Shan Liu ◽  
Lian Hua Fu
Keyword(s):  
Calcium Carbonate ◽  
Biomedical Applications ◽  
Value Added ◽  
Functional Materials ◽  
Industrial Applications ◽  
Precipitation Method ◽  
Synthesis Methods ◽  
Water Pretreatment ◽  
Potential Applications ◽  
Co Precipitation

CaCO3 has six polymorphs such as vaterite, aragonite, calcite, amorphous, crystalline monohydrate, and hexahydrate CaCO3. CaCO3 is a typical biomineral that is abundant in both organisms and nature and has important industrial applications. Cellulose could be used as feedstocks for producing biofuels, bio-based chemicals, and high value-added bio-based materials. In the past, more attentions have been paid to the synthesis and applications of CaCO3 and cellulose/CaCO3 nanocomposites due to its relating properties such as mechanical strength, biocompatibility, and biodegradation, and bioactivity, and potential applications including biomedical, antibacterial, and water pretreatment fields as functional materials. A variety of synthesis methods such as the hydrothermal/solvothermal method, biomimetic mineralization method, microwave-assisted method, (co-) precipitation method, and sonochemistry method, were employed to the preparation of CaCO3 and cellulose/CaCO3 nanocomposites. In this chapter, the recent development of CaCO3 and cellulose/CaCO3 nanocomposites has been reviewed. The synthesis, characterization, and biomedical applications of CaCO3 and cellulose/CaCO3 nanocomposites are summarized. The future developments of CaCO3 and cellulose/CaCO3 nanocomposites are also suggested.

Study on Different Synthesis Methods of Spherical YAG:Ce3+ Phosphor and its Luminescence Properties

2015 ◽  
Vol 1088 ◽  
pp. 371-376 ◽  
Author(s):  
Xia Zhang ◽  
Cui Xia Yan ◽  
Rong Feng Guan
Keyword(s):  
Sol Gel ◽  
Spherical Particles ◽  
Luminescence Properties ◽  
Precipitation Method ◽  
Thermal Method ◽  
Synthesis Methods ◽  
Processing Parameter ◽  
Gel Method ◽  
Sol Gel Method ◽  
Co Precipitation

Spherical YAG:Ce3+phosphors were synthesized by three different routes namely sol-gel method, co-precipitation method and solvethermal method. The microstructure, crystallization and luminescent properties of the phosphors were studied in order to find the best processing parameter for spherical shape and good luminescence properties of YAG:Ce3+phosphor. Adding citric acid to the precursor solution resulted in the formation of spherical particles in sol-gel method. YAG:Ce3+phosphor made by co-precipitation method was separated with PEG2000, and its spherical particles of size was around 500nm. The hydro-thermal method could get perfect spherical appearance, but it needed heat treatment improve the luminescence property.

scholarly journals The Influence of the Preparation Method on the Physico-Chemical Properties and Catalytic Activities of Ce-Modified LDH Structures Used as Catalysts in Condensation Reactions

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6191
Author(s):  
Alexandra-Elisabeta Stamate ◽  
Rodica Zăvoianu ◽  
Octavian Dumitru Pavel ◽  
Ruxandra Birjega ◽  
Andreea Matei ◽  
...  
Keyword(s):  
Preparation Method ◽  
Mixed Oxides ◽  
Condensation Reaction ◽  
Chemical Properties ◽  
Precipitation Method ◽  
Synthesis Methods ◽  
Molar Ratios ◽  
Base Catalysts ◽  
Physico Chemical ◽  
Co Precipitation

Mechanical activation and mechanochemical reactions are the subjects of mechanochemistry, a special branch of chemistry studied intensively since the 19th century. Herein, we comparably describe two synthesis methods used to obtain the following layered double hydroxide doped with cerium, Mg3Al0.75Ce0.25(OH)8(CO3)0.5·2H2O: the mechanochemical route and the co-precipitation method, respectively. The influence of the preparation method on the physico-chemical properties as determined by multiple techniques such as XRD, SEM, EDS, XPS, DRIFT, RAMAN, DR-UV-VIS, basicity, acidity, real/bulk densities, and BET measurements was also analyzed. The obtained samples, abbreviated HTCe-PP (prepared by co-precipitation) and HTCe-MC (prepared by mechanochemical method), and their corresponding mixed oxides, Ce-PP (resulting from HTCe-PP) and Ce-MC (resulting from HTCe-MC), were used as base catalysts in the self-condensation reaction of cyclohexanone and two Claisen–Schmidt condensations, which involve the reaction between an aromatic aldehyde and a ketone, at different molar ratios to synthesize compounds with significant biologic activity from the flavonoid family, namely chalcone (1,3-diphenyl-2-propen-1-one) and flavone (2-phenyl-4H-1benzoxiran-4-one). The mechanochemical route was shown to have indisputable advantages over the co-precipitation method for both the catalytic activity of the solids and the costs.

Impact of Synthesis Methods on Structural and Antifungal Properties of Metal Sulfide Nanoparticles

2021 ◽  
Vol 21 (12) ◽  
pp. 5896-5905
Author(s):  
Radha Ahuja ◽  
Anjali Sidhu ◽  
Anju Bala
Keyword(s):  
Electron Microscope ◽  
Chemical Properties ◽  
Metal Sulfide ◽  
Phytopathogenic Fungi ◽  
Biologically Active ◽  
Precipitation Method ◽  
Synthesis Methods ◽  
Sonochemical Method ◽  
Antifungal Properties ◽  
Co Precipitation

Nanotechnology has the ability to produce novel nano-sized materials with excellent physical and chemical properties to act against phytopathogenic diseases, essential for revolution of agriculture and food industry. The development of facile, reliable and eco-friendly processes for the synthesis of biologically active nanomaterials is an important aspect of nanotechnology. In the present paper, we attempted to compare sonochemical and co-precipitation method for the synthesis of metal sulfide nanoparticles (MS-NPs) for their structural and antifungal properties against various phytopathogenic fungi of rice. The preparation of nanospheres (NSs) and nano rods (NRs) of CuS, FeS and MnS was monitored by UV-Visible spectroscopy complemented by transmission electron microscope (TEM), scanning electron microscope (SEM), atomic force microscopy (AFM), dynamic light scattering (DLS) and Zeta potential analyser. Sonochemical method resulted in formation of spherical shaped nanoparticles of size (7–120 nm), smaller than those of nanorods (50–200 nm) prepared by co-precipitation produced. It was observed that the metal sulfide nanospheres exhibited a better antifungal potential against D. oryzae, C. lunata and S. oryzae as compared to rod shaped metal sulfide nanoparticles. Smaller size and large surface area of spherical shaped particles opens up an important perspective of the prepared MS-NPs.

Synthesis and Characterization of Magnetic Fe3O4/PAAm/LMSH Nanocomposite Hydrogel

2016 ◽  
Vol 848 ◽  
pp. 49-56 ◽  
Author(s):  
Shu Qiong Ma ◽  
Hai Hui Bai ◽  
Ran Jin ◽  
Qing Song Zhang ◽  
Xiao Nan Zheng ◽  
...  
Keyword(s):  
Magnetic Particles ◽  
Removal Rate ◽  
Testing Machine ◽  
Magnetic Characteristic ◽  
Magnesium Silicate ◽  
Adsorption Properties ◽  
Precipitation Method ◽  
Nanocomposite Hydrogel ◽  
Swelling Rate ◽  
Co Precipitation

Based on the preparation of polyacrylamide/clays lithium magnesium silicate hydrate (PAAm/LMSH, abbreviated as AP) nanocomposite hydrogel by in-situ free radical polymerization, Fe3O4 nanoparticles were introduced by chemical co-precipitation method, to form magnetic Fe3O4/PAAm/LMSH (abbreviated as MAP) nanocomposite hydrogel. With ESEM, XRD, and TGA technologies, the structures of MAP nanocomposite hydrogel and Fe3O4 nanoparticles formed. Magnetic characteristic of MAP nanocomposite hydrogel was characterized by VSM. The tensile test with Universal Testing Machine was employed for mechanical properties. Furthermore, taking cationic dye Crystal Violet (CV) and anionic dye Methyl Orange (MO) for example, the adsorption properties of MAP nanocomposite hydrogel were analyzed with UV-visible spectrophotometer method. The results show that MAP nanocomposite hydrogel had strong superparamagnetic properties. The introduced Fe3O4 magnetic particles illustrated spinel structure, and nanoparticle size of 8.52 nm. The swelling rate of MAP sample was up to 30.542, showing excellent swelling ability. Compared with AP nanocomposite hydrogel, MAP nanocomposite hydrogel had stronger mechanical strength with the tensile stress of 0.39MPa. Adsorption experiments indicated that MAP nanocomposite hydrogel had favorable adsorption properties on CV with removal rate of 97.6%, 1.27 times that of AP nanocomposite hydrogel. The conclusions confirm the application prospect of MAP nanocomposite hydrogel as dye adsorbent in textile printing and dyeing wastewater treatment.

scholarly journals Comparative studies on impact of synthesis methods on structural and magnetic properties of magnesium ferrite nanoparticles

2014 ◽  
Vol 8 (3) ◽  
pp. 137-143 ◽  
Author(s):  
Navneet Kaur ◽  
Manpreet Kaur
Keyword(s):  
Sol Gel ◽  
Thermolysis Product ◽  
Ferrite Nanoparticles ◽  
Precipitation Method ◽  
Synthesis Methods ◽  
Magnesium Ferrite ◽  
Solution Combustion ◽  
Magnetic Parameters ◽  
Physical Density ◽  
Co Precipitation

Magnesium ferrite nanoparticles (NPs) were synthesized by co-precipitation, sol-gel and solution combustion methods. Polyethylene glycol (PEG), urea and oxalyl dihydrazide (ODH) were used as fuels for the combustion. Various physicochemical techniques viz. X-ray diffraction (XRD), vibrating sample magnetometry (VSM), Fourier transform infrared spectroscopy (FT-IR), BET surface analysis and transmission electron microscopy (TEM) were utilized to study the effect of synthetic methodology on the properties of synthesized NPs. Differences in crystallinity, surface area, particle size and magnetic parameters of the ferrite NPs synthesized by different methods were observed. XRD pattern of NPs obtained by sol-gel and combustion methods confirmed phase purity where as in co-precipitation method ?-Fe2O3 was detected as impurity phase which also resulted in greater value of physical density and lowering of magnetic parameters of the final thermolysis product. TEM micrographs indicated that ferrite NPs are spherical with average diameter of 12-25 nm. Presence of rectangular shaped crystallites of ?-Fe2O3 was clearly evident in the TEM images of the NPs synthesized by co-precipitation method.

Green Magnetic Composite Sheet from Durian Shell and Nano-Magnetite Particles

2015 ◽  
Vol 761 ◽  
pp. 515-519 ◽  
Author(s):  
Mohd Khairul Shahril ◽  
Rose Farahiyan Munawar ◽  
Muhd Hafez Mohamed ◽  
Afraha Baiti Arif ◽  
Noraiham Mohamad ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Particles ◽  
Added Value ◽  
Precipitation Method ◽  
Magnetic Composite ◽  
Great Success ◽  
Composite Sheet ◽  
Biomass Waste ◽  
Co Precipitation

Biomass-derived materials such as kenaf pulp and wood chips are a perfect candidate to produce magnetic paper. Furthermore, by using biomass waste, such as paddy straw, sugarcane, bagasse and durian shell, the cost of producing magnetic paper can be further reduced while giving added value to the waste. This paper investigates the potential of producing magnetic sheet from durian shell. Initially, durian shells were dried before undergoing the pulping process. The resulted sheet was then combined with magnetic particles, the nanomagnetite using either lumen loading or in-situ co-precipitation to produce a magnetic composite sheet. After being loaded with magnetic particles, the composite sheets were tested in terms of the homogeneity of the magnetic particles in the samples, degree of loading of the magnetic particles and the magnetic properties of the samples. Results obtained show a great success in producing the magnetic sheet from durian shell waste and nanomagnetite particles. It was also found that the lumen loading method gives better magnetic properties compared to the in-situ co-precipitation method.

Preferential killing of bacterial cells by surface-modified organosilane-treated ZnO quantum dots synthesized through a co-precipitation method

2021 ◽  
Author(s):  
Hariventhan Ragupathi ◽  
Youngson Choe ◽  
Antony Arockiaraj M.
Keyword(s):  
Quantum Dots ◽  
Precipitation Method ◽  
Bacterial Cells ◽  
Antiviral Activities ◽  
Zno Quantum Dots ◽  
Co Precipitation ◽  
Surface Modified

The aim of this study was to screen and determine the significant antibacterial/antiviral activities of surface-modified ZnO@MPS QDs owing to their impressive activities against microorganisms.

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