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Background Cereals and cereal-based products as an important part of the daily diet provide a considerable percent of macronutrients such as carbohydrate, protein and fiber and a range of micronutrients including vitamins (E and some of the B vitamins) and minerals (Mg and Zn). However, thermal (boiling or baking) and mechanical (milling) processes applied for conversion of cereals into consumable products and also improvement of the digestibility and palatability of cereal products lead to the reduction or even removal of some bioactive compounds, consequently loss of their nutritional and health values. Scope and approach The fortification process is a suitable means for the addition of the lost components to the formulation of cereals; although, direct usage of bioactive compounds and additives in bakery products has some limitations such as sensitivity to undesirable environmental and processing conditions, adverse effects on sensory attributes of products and interaction with other food ingredients. Encapsulation not only can solve these problems, but also improves the overall quality and shelf life of bakery products by release controlling, protecting and uniform distribution of these components. Key findings and conclusions Most studies in the literature show that the use of bioactive substances instead of free compounds can be used effectively to enrich or fortify cereal-based products, without having a significant negative impact on their physicochemical and textural properties. Spray drying was the most commonly used technique for encapsulation of bioactive compounds, which can be explained by its advantages such as flexibility and low cost. This review will provide valuable information that may be useful for identifying trends in the production of new functional cereal-based products through nano/microencapsulation technology. However, it is necessary to pay attention to the commercialization and also the safety of nanoformulations used in cereal products.

Metal-oxide based gas sensors are widely used as the gas sensing elements in industrial and residential areas. Many efforts have been made to increase sensitivity and reduce the working temperature of metal-oxide based gas sensors. In this paper, ZnO nanowires (NWs) were successfully grown on graphene (Gr) nanosheets by the hydrothermal method. The synthesized Gr/ZnO NWs nanocomposite were investigated as the sensing material. Not only is the sensor response much higher, it also works in a lower working temperature toward a low concentration of ethanol in comparison with pure ZnO NWs. The optimum working temperature is reduced from 200 °C in pure ZnO NWs to 125 in Gr/ZnO NWs sensor. The maximum response of the Gr/ZnO NWs sensor is 26, which is approximately enhanced twice as much as the pure ZnO NWs sensor. The lower limit of detection (LLOD) of the proposed sensor is as low as 1 ppm ethanol vapor. The sensor was shown a high response, good selectivity, fast response toward ethanol vapor, excellent repeatability, and low sensitivity toward a high relative humidity, as well as remarkable long-term stability.

The fabrication of magnetic porous nanocomposites is of great significance owing to their excellent properties and their application as promising catalysts. Herein, a novel covalent organic framework (COF)-modified magnetic chitosan (CS) supported copper (Fe3O4/CS/COF/Cu) nanocomposite was prepared through modification of Fe3O4 with CS, chemical attachment of melamine-rich COF on Fe3O4/CS followed by reaction with Cu(NO3)2·3H2O. The resulting nanocomposite was characterized by FT-IR, XRD, SEM, TEM, EDX, BET and VSM analyses. Fe3O4/CS/COF/Cu possesses large specific surface area and supermagnetism, making it an ideal catalyst for the organic reactions. Thus, Fe3O4/CS/COF/Cu was applied as an efficient and recoverable catalyst for the green and rapid synthesis of biologically active polyhydroquinoline derivatives via the unsymmetric Hantzsch reaction under solvent-free conditions. Fe3O4/CS/COF/Cu exhibits high reactivity and selectivity for the preparation of different derivatives of polyhydroquinolines under mild reaction conditions and short time. Furthermore, the catalyst was recovered and reused several times without an important decrease in efficiency.

Background Curcumin, the major bioactive material of turmeric, has wide functional features such as anti-diabetic, anti-cancer, anti-inflammatory, and antioxidant activities. However, curcumin exhibits some major limitations including low water solubility, degradation during processing or within the gastrointestinal tract and alkaline conditions, leading to decrease of its bioavailability. For these reasons, many studies have tried to improve functionality of curcumin and overcome its limitations through delivery systems, especially nanoencapsulation. Scope and approach In this review, practical applications of the nanoencapsulated curcumin, prepared by various techniques in different food, pharmaceutical and cosmetic products have been considered and explained. The importance of nanoencapsulation in improving functional effects of curcumin in processed foods, such as coloring, antioxidant and antimicrobial activity has been discussed thoroughly and its potential applications for medicinal proposes including cancer, cardiovascular and neurodegenerative diseases, viral and bacterial infections have been reviewed. Key findings and conclusions Nano-delivery systems, because of exclusive characteristics of nanoparticles as well as conventional properties of an encapsulation medium, can provide chemical stability, hydrophilicity, sustained release and adequate dispersibility of curcumin in final products (food, cosmetics and drug). Consequently, the pharmacokinetic properties of curcumin including biological half-life and bioavailability (or bioaccessibility) can be improved resulting in better clinical and functional efficacy in vivo. Although the potentials of curcumin nanoformulations have been extensively studied in the literature, future studies can better help to find optimum formulations for clinical and industrial applications of nanoencapsulated curcumin.

In recent decades, due to the increase in awareness, most consumers prefer foods that not only satisfy their primal urge of hunger but also include health-promoting effects on the body. Therefore, the food industry has an increasing tendency to apply the nutrients (like vitamins, essential fatty acids and minerals) and replace synthetic additives with natural bioactives (like phenolics and essential oils) to produce functional products. However, low dispersibility and shelf-stability as well as presenting unpleasant taste and odor are the most critical barriers for direct incorporation of these useful compounds into foods. In this context, nanoencapsulation has been proposed as a relatively new solution to overcome the mentioned limitations. However, fewer studies have focused on incorporating the bioactive-loaded nanocarriers into the food matrices. This study intends to help the development of functional food production by doing an exhaustive review on the incorporation of nanoencapsulated ingredients into the real food system and resulted interaction of nanocarriers and food products. According to the literature, incorporation of the nanoencapsulated bioactive ingredients into foods can be effectively used to enhance their stability during the processing and storage stage and their bioavailability as well as to delay lipid oxidation and microbial growth in food, without negatively affecting physicochemical, organoleptic and qualitative properties. However, some published results to date declared that food matrix might adversely affect the bioavailability and antimicrobial activity of nanoencapsulated ingredients. It seems that further studies are required to contribute to the choice of appropriate healthy ingredients and wall materials for incorporating into a given food structure.

Zeolitic imidazolate framework materials belong to an important class of Metal-organic frameworks that show attractive applications in various fields including adsorption and chemical separation. In this study, nonwoven fibrous polyester sponge surface was modified by cross-linked carboxymethyl cellulose and synthesized ZIF-8 and used to remove methylene blue dye from aqueous solution. The prepared filter was characterized using Field Scanning Electron Microscopy, Fourier Transform Infrared Spectrometer, X-ray Diffraction, and nitrogen adsorption-desorption analyses, and effects of contact time and dye concentration were investigated in batch and continuous fixed bed dye adsorption processes. Batch kinetics experimental data were estimated with the models of pseudo-first-order, pseudo-second-order, Elovich, and intra-particle, and continuous kinetics experimental data were estimated with Thomas, Adams-Bohart, and Yoon-Nelson models. Batch and continuous adsorption kinetics were more consistent with the pseudo-second-order and the Yoon-Nelson models, respectively. The filter adsorption capacity were 0.824 and 0.829 mg/g in continuous and batch systems at initial concentration of 8 mg/L, respectively. With increasing initial dye concentration from 2 to 8 mg/L, the adsorption capacity was increased about 80 and 90% in batch and continuous systems, respectively. By regeneration experiments after 5 cycles, acceptable results were observed.

In present study, nanoliposomes were prepared by thin hydration method with different concentrations of phenolic compounds (500, 750 and 1000 ppm) of pure extract and lecithin (1, 2 and 3% w/w) and characterized by considering the particle size, polydispersity index (PDI), zeta potential, encapsulation efficiency (EE) and morphology. The results showed that nanoliposome (90.39–103.78 nm) had negative surface charge varied from −51.5 ± 0.9 to −40.2 ± 0.2 mV with a narrow size distribution (PDI ≈ 0.069–0.123). Nanoliposomes composed of 1% lecithin with 1000 ppm of phenolic compounds had the highest EE (52.93%). The FTIR analysis indicated the formation of hydrogen bonds between the polar zone of phospholipid and the OH groups of phenolic compounds. Phenolic compounds also increased phase transition temperature ( Tc ) of nanoliposomes (2.01–7.24 °C). Moreover, nanoliposomes had considerable stability during storage. Consequently, liposome is an efficient carrier for protection and improving PGHE biofunctional actives in foodstuffs.

ZnO nanowires (NWs) are known to be highly sensitive to glucose due to their strong electron transfer and adsorption as well as stability and high surface to volume ratio. On the other hand, thanks to its suitable conductivity, and chemical stability, Graphene is the most rampant nanomaterial used in electrochemical sensors. We have previously reported the fabrication of a glucose biosensor based on ZnO NWs synthesis on an Au interdigitated electrode. In this paper, we present the modification of the sensor by incorporation of Graphene Nanoplates (GNPs) beneath the ZnO NWs to achieve a glucose biosensor with high proficiency. The experimental results show excellent improvement in the sensor performance in glucose detection due to this modification. The synergetic effects of ZnO NWs and GNPs have resulted in a desirable performance by the proposed sensor. The response time of 5 s, the detection range of 0.003–30000 mg/dL and long-term electrical stability are three outstanding characteristics of the sensor.

Maintaining connectivity to the grid and resisting against voltage dip in the grid are important for doubly fed induction generator based wind farms (DFIG-based WFs) to meet the requirements of new grid codes. In this paper, a hybrid approach is proposed to improve low voltage ride through (LVRT) capability in DFIG-based WF using an improved series resistive limiter (SRL) in rotor and superconducting magnetic energy storage (SMES) as an improved chopper circuit (ICC) along with the transient voltage control (TVC) method. The connection of the wind turbine to the grid while preventing the disturbances duo to the voltage dip (VD) through compensating the VD by using the proposed controller and ICC method. The new control method relies on active power control and reactive power injection to the grid for improving the performance of DFIG-based WF during the grid VD. The proposed controller and ICC method reduce the VD at the point of common coupling (PCC) while improving the overall system performance by injecting active and reactive power into the grid during a fault. In addition, the proposed methods effectively improves the LVRT capability of the generator and maintains its controllability during a fault Compared to other solutions including the crowbar parallel resistance. The proposed methods are simpler, cheaper, and have less computational complexity compared to active methods including series voltage compensator of the stator along with power electronic converters (PEC). Finally, the continuous operation of a 9 MW wind turbine during a VD in the grid has been investigated and simulated using the proposed method in Matlab/Simulink®.

In this study, novel polyurethane/cellulose hybrid bionanocomposite films have successfully been prepared by dispersing microcrystalline cellulose in a polyurethane matrix. Incorporation of microcrystalline cellulose in a polyurethane matrix improved the mechanical properties significantly. The polyurethane/cellulose bionanocomposites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and transmission electron microscopy (TEM). The TEM results confirm that the nanoparticles were dispersed uniformly in polymer matrix. Additionally, thermogravimetric analysis data showed an improvement of thermal stability of novel nanocomposite films as compared to the neat polymer.

Here, a selective nano-sized magnetic sorbent based on iron oxide (Fe3O4) core and molecular imprinted polymer (MIP) shell was synthesized and used as a selective sorbent for separation of piroxicam (PIX) from aqueous media. The magnetic MIP functionalized with NH2 group (Fe3O4@SiO2@NH2) was prepared by a surface imprinting approach. The characterization of the MMIP sorbent was carried out by scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Brumauer-Emmett-Teller (BET) and Barrett–Joyner–Halenda (BJH) analyses. The results indicated that the magnetic sorbent were as microspherical nanoparticles with the average size of 50 nm, with well water-dispersibility and easily magnetically separation. The influence of the variables on PIX recovery including initial pH of sample solution, volume and concentration of the eluent, ultrasonic time, ionic strength, and the amount of MMIP were studied and optimized. The linear range (LR), relative standard deviation (RSD) and limit of detection (LOD = 3Sb/m) for determination of PIX were found to be 0.01–10.0 mg L−1, 2.56 % and 5.0 ng mL−1, respectively. The used Fe3O4@SiO2@NH2-MMIP sorbent can be regenerated with 2 ml of pure methanol, without any significant decrease in its adsorption affinity. The results demonstrated an enhanced affinity for the as-prepared MMIP toward the PIX compared to non-imprinted polymer.

In this study, a novel mesoporous silica nanocomposite (MSNC) based on poly(acrylic acid) and amine-functionalized MCM-41 mesoporous silica as amplification agents was constructed via an ultrasonic-assisted method as a straightforward, fast, eco-friendly and it is denoted as M-MCM-41. Then Cu (II) was immobilized on PAA/M-MCM-41 surface and the novel heterogeneous reusable catalyst was fully characterized using appropriate techniques such as Fourier transform infrared (FT-IR), X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), field emission scanning electron microscopy (FE-SEM), thermogravimetry analysis (TGA) and N2 adsorption–desorption. The resulting catalyst was successfully used for the condensation of various aromatic aldehydes, dimedone, s-ketoester and ammonium acetate under solvent-free and mild conditions to yield polyhydroquinoline derivatives in good to excellent yields. Also, the experimental evidence was demonstrated that Cu (II)-PAA/M-MCM-41 nanocomposite could act as a recoverable and reusable nanocatalyst without a meaningful drop in the yield and the reaction time at least four times.

The purpose of this review is to provide appropriate details concerning the application of ionic liquids (IL)s associated with microwave-assisted polymer chemistry. From the viewpoint of microwave chemistry, one of the key significant advantages of ILs is their high polarity, which is variable, depending on the cation and anion and therefore can effectively be tuned to a particular application. Hence, these liquids offer a great potential for the innovative application of microwaves for organic synthesis as well as for polymer science. ILs efficiently absorb microwave energy through an ionic conduction mechanism, and thus are employed as solvents and co-solvents, leading to a very high heating rate and a significantly shortened reaction time. Since an IL-based and microwave-accelerated procedure is efficient and environmentally benign, we believe that this method may have some potential applications in the synthesis of a wide variety of vinyl and non-vinyl polymers. This review describes application of combination of ILs with microwave irradiation as a modern tool for the addition and step-growth polymerization as well as modification of polymers and it was compared with ILs alone and conventional polymerization method.

A novel compound constructed from polyoxometalate (H3PW12O40, PW12) and poly(amidoamine) (PA) was prepared at room temperature in an aqueous solution by an impregnation method. A series of novel 1,3,5-triaryl-2-pyrazoline derivatives was synthesized by the reaction between chalcone and phenylhydrazine in the presence of the title compound, PW12/PA, in high yields. The structures of the compounds obtained were determined by IR and 1H NMR spectra.

A new diacid monomer, 5-[3-phenyl-2-(9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboximido)propanoylamino]isophthalic acid was successfully synthesized starting from cis -9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid anhydride and l -phenylalanine. A highly effective, very fast microwave method is described to synthesize optically active aromatic polyamides (PA)s under microwave heating for only 3 min. Generally, better yields are obtained under faster and cleaner reactions when compared to those from conventional heating. Therefore, this approach could considerably reduce the synthesis time, cost, and energy. The resulting PAs had inherent viscosities in the range of 0.35–0.58 dL/g. All of the these polymers having bulky anthracenic and amino acid functionality in the side chain showed excellent solubility and readily dissolved in various solvents such as N- methyl-2-pyrrolidinone, N,N -dimethylacetamide and N,N -dimethylformamide. PAs were thermally stable, with 10% weight loss recorded at 385 °C and 341 °C in the nitrogen atmosphere, and char yields at 800 °C higher than 50% and glass transition temperature above 180 °C.

Ionic liquids are outstanding microwave-absorbing agents owing to their high ionic conductivity and polarizability, thus leading to a high heating rate and a considerably shortened reaction time. In this study, a series of novel optically active polyamides ( PA )s with pendent 4-(2-phthalimidiyl-propanoylamino)benzamide units were prepared with excellent yields via a simple microwave heating method using 1,3-dipropylimidazolium bromide and triphenyl phosphite. In comparison with classical heating, microwave irradiation was demonstrated to be a more effective energy source. The resulting PA s have inherent viscosity in the range of 0.52–0.71 dL/g. All of the polymers were readily soluble in many organic solvents and showed good thermal stability associated with high glass-transition temperatures above 200 °C as measured by differential scanning calorimetry. Thermogravimetric analysis showed that the 10% weight-loss temperatures in nitrogen were 455 and 410 °C, a significant improvement in thermal stability having been observed with the increase in the side-chain length.

An efficient, fast and easy method for synthesis of new optically active and thermally stable aromatic polyamides (PAs) containing pendent phthalimide group and l -alanine flexible side spacer using room temperature ionic liquid (RTIL) by microwave irradiation has been investigated. The results found that RTIL efficiently absorb microwave energy, thus leading to a very high heating rate. All the PAs showed excellent solubility and readily dissolved in various organic solvents. Thermogravimetric analysis (TGA) exhibited that polymers were stable, with 10% weight loss recorded above 373 and 418 °C in the nitrogen atmosphere. In order to see the efficiency of microwave irradiation, this method was compared with polycondensation of the same monomers in RTILs using conventional heating.

Dicarboxylic acid, 5-(3-acetoxynaphthoylamino)isophthalic acid was prepared in three steps. The direct polycondensation of this novel diacid with several aromatic diamines was studied in 1,3-diisopropylimidazolium bromide as an ionic liquid ( IL ) under microwave irradiation and conventional heating. The polymerization reaction was effectively preceded in IL , and triphenyl phosphite as an activating agent, and the resulting novel photoactive polyamides were obtained in high yields and moderate inherent viscosities in the range of 0.44–0.69 dL/g. Thermogravimetric analysis showed that polymers are thermally stable, 10% weight loss temperatures in excess of 390 and 470 °C, and char yields at 600 °C in nitrogen higher than 60%. These macromolecules exhibited maximum UV–vis absorption at 265 and 300 nm in N , N -dimethylformamide (DMF) solution. Their photoluminescence in DMF solution demonstrated fluorescence emission maxima around 361 and 427 nm for all of the polyamides. It is very important to note that, because of, high polarizability of IL s, they are very good solvents for absorbing microwaves.

In this investigation, a novel urazole containing 3-hydroxynaphthalene group, 4-(3-hydroxynaphthalene)-1,2,4-triazolidine-3,5-dione (3HNTD) was synthesized in six steps starting from 3-hydroxy-2-naphthalene carboxylic acid. The reaction of 3HNTD with n-propylisocyanate was performed in N,N-dimethylacetamide solution at different molar ratios, and the resulting monosubstituted as well as disubstituted urea derivatives were obtained in high yields and were used as model compounds for polymerization studies. An efficient, fast and easy method for the preparation of new soluble poly(urea-urethane)s (PUU)s containing heterocyclic and chromophoric moieties from 3HNTD and various diisocyanates are employed using room temperature ionic liquids and molten tetrabutylammonium bromide under microwave irradiation as well as conventional heating. The polymerization reactions occurred rapidly under microwave and produced a series of PUUs with good yields and moderate inherent viscosities of 0.21–0.46 dL/g. All of the new PUUs showed good solubility and were readily dissolved in organic solvents.

This is the first report of application of molten ionic liquid (MIL) for the synthesis of heterocyclic polyureas. An inexpensive and readily available MIL, tetrabutylammonium bromide (TBAB) was used for the synthesis of polymers. Therefore, polycondensation of 4-(4-dimethylaminophenyl)-1,2,4-triazolidine-3,5-dione (DAPTD) with various commercially available diisocyanates was performed in molten TBAB with or without dibutyltin dilurate (DBTDL) as a catalyst. The polymerization reaction gave similar results in the presence or absence of DBTDL, indicating that, the catalyst was not needed in this process. Various polyureas were obtained with high yields and moderate inherent viscosities ranging from 0.26 to 0.38 dL/g. This method was compared with the polymerization reaction in conventional solvent and in the presence of DBTDL as a catalyst. In the case of using TBAB, higher yields and inherent viscosities were obtained. This process was safe and green since toxic and volatile solvent such as N,N-dimethylacetamide (DMAc) was eliminated.