Dynamically controlled fibrillation under combination of ionic liquid with mechanical grinding

Combination of mortar grinder mill (MG) and ionic liquid (IL) treatment was employed in order to fibrillate fibers from oil palm mesocarp fiber (OPMF) in one‐step. The structural changes of OPMF before and after the treatment were examined by Thermogravimetric analysis (TGA), Fourier transformed infrared (FT‐IR) spectra, Wide‐angle X‐ray diffraction (WAXD), Dynamic light scattering (DLS) and Scanning electron microscopy (SEM). Compared with the only use of 1‐butyl‐3‐methylimidazolium tetrafluoroborate (BMIM[BF₄]), combination of MG and IL helped to remove hemicellulose and lignin components partially from OPMF, and also fibrillated OPMF fibers at average particle diameter of 127 nm. Afterwards, the fibrillated fibers were utilized as reinforcement material for the purpose of enhancement of mechanical properties of poly(?‐caprolactone)(PCL). The addition of OPMF treated with the combined method led to a 64% increase in tensile strength in comparison with that of untreated OPMF. These results indicate that the combined method enables effective fibrillation. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44469.     

Thermally curable main-chain benzoxazine prepolymers via polycondensation route

Polybenzoxazines are addition-cure thermosetting polymers exhibiting versatility in a wide range of applications due to their good mechanical properties, dimensional stability, chemical resistivity, flame resistance property phenolic or epoxy resins have myriad applications in diverse fields starting from commodity materials to high technology aerospace industries. In this paper, we present synthetic strategies to incorporate thermally curable benzoxazine functionality into polymers as main-chain fashion in order to further improve various properties. The strategies successfully employed including monomer synthesis and polycondensation routes like Mannich reaction, click chemistry, hydrosilylations, and coupling reactions. The structure–property relationships of the cured materials have also been presented and discussed.     

An investigation of the titanium effect on the structural and magnetic properties of BaNi2 based W-type hexaferrites

The polycrystalline samples of the composition Ba(Ni_1?xTi_x)₂Fe₁₆O₂₇ were prepared by the conventional ceramic method with (x = 0.0–1.0). Effects of titanium (Ti) doping on structural and magnetic properties of BaNi₂ based W-type hexaferrites were analyzed. The samples were initially sintered in air at 1000 °C for 4 h and finally at 1300 °C for 9 h. The X-ray diffraction patterns confirm the presence of single W-hexagonal phase. The lattice parameters ‘a’ and ‘c’ were found to show irregular behavior by increasing Ti content. The variations of magnetic properties were observed by analyzing hysteresis loop of prepared samples. The results show that maximum magnetization (M) and remanence (M_r) decrease up to x ≤ 0.6 due to replacement of Ti ions for spin down (4f₂) and spin up (12k, 2a and 2b) sublattices, but a substantial increase of M and M_r for (x = 0.8 and1.0) could be attributed to the replacement of Ti ions for spin down sublattices (4f₂). The coercivity (H_c) was found to decrease with increasing Ti content. An increase of grain size with Ti content was also observed. Since, H_c is inversely proportional to the packing fraction of magnetic materials or the grain size.     

Gallic acid crosslinked peanut protein-corn starch composite edible films produced at alkaline pH with ultrasound application

Corn starch and peanut protein blend films were prepared with and without gallic acid addition (0.25%, w/v) at pH 7, 9, and 11 by casting. The ultrasound (160 W, 20 kHz, 10 min) treatment was applied to the film-forming solutions. This study aimed to develop biopolymer-based films with gallic acid and to determine the interactions of components at different pHs and with ultrasound. The barrier, optical, mechanical, and thermal properties of films were examined. Moreover, structural characterization of films was conducted by Fourier transform infrared (FTIR), x-ray diffraction, and trinitro benzenesulfonic acid assay to enlighten the crosslinking interactions of gallic acid with biopolymers at different pHs. At neutral pH, gallic acid behaved as plasticizer. By acting as a crosslinker at pH 9, gallic acid provided the lowest moisture content, darker and more opaque appearance, enhanced barrier performance and thermal stability. The crosslinking degrees of gallic acid-enriched films were 49.1% (pH 7), 77% (pH 9), and 67.4% (pH 11). Additionally, gallic acid increased antioxidant capacity. The ultrasonication adversely affected the film properties by breaking bonds in the film structure. Peanut protein-corn starch-gallic acid films under mild alkaline conditions exhibited outstanding thermal stability, mechanical durability, light, and water barrier characteristics, making them appropriate for sustainable food packaging applications.     

Influence of different drying methods on carotenoids and capsaicinoids of paprika (Cv., Jalapeno)

Influence of Refractance Window™ Drying (RWD), a novel contact drying method, on carotenoids, capsaicinoids, Retinol Activity Equivalent (RAE) and Scoville Heat Unit (SHU) of paprika (Cv., Jalapeno) was investigated in comparison with freeze drying (FD), oven drying (OD), and natural convective drying (NCD) methods. Eight carotenoids (capsanthin, capsorubin, capsolutein, β-carotene, β-cryptoxanthin, mutatoxanthin, violaxanthin and zeaxanthin) and five capsaicinoid analogues (capsaicin, dihydrocapsaicin, homodihydrocapsaicin, isodihydrocapsaicin, nordihydrocapsaicin) were identified in paprika. All these components were significantly (P < 0.05) decreased by the RWD, FD and OD methods. However, due to ongoing synthesis, the NCD method resulted in higher carotenoids, except violaxanthin and mutatoxanthin, and capsaicinoids content than those of the others, even puree. Mutatoxanthin, naturally occurring pigment in red pepper, could only be detected in FD paprika. The highest RAE and SHU values, which were derived from the data of carotenoids and capsaicinoids, respectively, were also determined in NCD paprika.     

Determining the effect of trace elements on biohydrogen production from fruit and vegetable wastes

Trace elements are one of the important parameters for dark fermentative H₂ production because they work as co-factors in H₂ formation biochemistry. Lack or excess of trace element and its concentrations could be an important reason for the low yield of H₂ production. In this study, the effects of 11 different trace elements (Fe, Ni, Zn, Co, Cu, Mn, Al, B, Se, Mo and W) were tested at two levels in terms of biohydrogen production from Fruit and Vegetable Wastes (FVW) with Biochemical Hydrogen Potential (BHP) Tests using Plackett-Burman statistical design. 1.1–2.8 times enhancement of biohydrogen production was determined with its addition. The most effective trace elements were found as Zn and Ni. In order to reveal the resident microbial flora, Denaturing Gradient Gel Electrophoresis (DGGE) analysis was carried out on all BHP effluent samples. Results of DGGE analysis, four microbial sequences evaluated as Clostridium sp., Clostridium baratii, Uncultured bacterium, Uncultured Streptococcus sp., and their similarity rates were 99%, 100%, 89%, 98%, respectively.     

Phenolic compositions and antioxidant activities of Maya nut (Brosimum alicastrum): Comparison with commercial nuts

The goal of the present study was to investigate the antioxidant activity and total phenolic content (TPC) of Maya nut (Brosimum alicastrum) in comparison with commercially available nuts (i.e. walnut, almond, and peanut). Results indicated that Maya nut had the highest TPCs among these nuts. Maya nut also possessed strong 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) and 2.2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) scavenging activities and ferric reducing antioxidant power (FRAP) (p < 0.05) as compared to walnut, almond, and peanut. Five phenolic acids (gallic acid, p-hydroxybenzoic acid, vanillic acid, caffeic acid, and p-coumaric acid) and one flavonoid ((-)-epicatechin) were identified and the phenolic content ranged from 6.5 to 326.2 µg/g.     

Bottom-up fabrication of n-ZnO-based memristor and p-Cu2O/n-ZnO heterojunction diode using electroless deposition

Journal of Materials Science: Materials in Electronics - This study introduces a low-cost and feasible electroless deposition technique utilized to fabricate an n-ZnO-based memristor and...