Phytosynthesis of Iron Oxide Nanoparticles using Juncus inflexus Shoot Extract

To elude the toxic effects of chemically synthesized nanoparticles, the phytochemically synthesized nanoparticles may provide a better alternative. For the first time, an aqueous extract of Juncus inflexus shoot with FeCl3.6H2O was used for the phytosynthesis of iron oxide nanoparticles (FeONPs). As-synthesized FeONPs were characterized by UV-Vis spectroscopy, Transmission electron microscopy (TEM), Dynamic light scattering (DLS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). FeONPs showed UV-vis absorption spectra between 300-400 nm, whereas TEM analysis confirmed the particle sizes of 40-60 nm with aggregation. XRD is confirming the polymorphic composition of Fe3O4, α-Fe2O3, and Fe0 nanoparticles. Furthermore, FTIR analysis presenting the most probable mechanism for the synthesis of FeONPs. This multiphase FeONPs was applied for the decolorization of methylene blue dye (>83%). Phytosynthesized FeONPs have the benefits of low cost, no toxicity, sustainable, and eco-friendly technology so that they may be used as adsorbent/catalyst for remediation of toxic dyes in an aqueous medium.

Influence of Selected Saccharides on the Precipitation of Calcium-Vaterite Mixtures by the CO2 Bubbling Method

Calcium carbonate is a compound existing in living organisms and produced for many biomedical applications. In this work, calcium carbonate was synthesized by a CO2 bubbling method using ammonia as a CO2 absorption promotor. Glucose, fructose, sucrose, and trehalose were added into the reaction mixture to modify characteristics of precipitated calcium carbonate particles. To determine the polymorphic form of produced calcium carbonate particles, Fourier transform infrared spectroscopy (FTIR-ATR) and X-ray diffraction (XRD) analysis were performed. Scanning electron microscopy (SEM) was used to estimate the size and shape of produced particles. Mixtures of vaterite and calcite were synthesized in all experiments. The percentage content of the vaterite in the samples depended on used additive. The highest concentration of vaterite (90%) was produced from a solution containing sucrose, while the lowest concentration (2%) was when fructose was added. Saccharides affected the rate of CO2 absorption, which resulted in a change in the precipitation rate and, therefore, the polymorphic composition of calcium carbonate obtained in the presence of saccharides was more varied.

Morphology Development, Structure and Dielectric Properties of Biaxially Oriented Polypropylene

<p>This paper outlines our recent study on effects of cast film extrusion and biaxial orientation on the morphological development and dielectric performance of biaxially oriented polypropylene (PP) films based on two capacitor-grade isotactic PP (iPP) raw materials. Results on polymorphic composition, melting behavior, microstructure and dielectric properties are reported. Morphological development during film manufacturing is found to have a profound effect on film structure and dielectric characteristics. Formation of structural defects was traced back to beta --&gt; alfa crystal transformation upon biaxial stretching.</p>

Study on low temperature toughness and crystallization behavior of polypropylene random copolymer

This research designed a series of novel approaches aiming to tackle a long-standing problem that is the brittleness of polypropylene (PP) random copolymer (PPR) at low temperature. By introducing polyolefin elastomer (POE), the toughness of PPR was improved; talc improved the stiffness of PPR, low density polyethylene (LDPE) or high density PE (HDPE) improved the low temperature toughness of PPR, and annealing treatment also improved the low temperature toughness of PPR significantly. The addition of dicumyl peroxide (DCP) and triallyl isocyanurate (TAIC) increased its stiffness through the formation of cross-linking networks. Also, the crystallization behavior and morphology were investigated in detail. Differential scanning calorimetry (DSC) results indicated that the adoption of annealing treatment can improve the crystallinity of PPR, while a polarizing microscope revealed that the incorporation of foreign matter can facilitate the crystallization process of the matrix. X-ray diffraction (XRD) tests showed an unchanged polymorphic composition of PPR after introducing different additives, and scanning electron microscopy (SEM) indicated that annealing treatment can enhance interfacial interactions between the matrix and fillers.

The correlation between structure and β-nucleation efficiency of Ba, Sr, Ca and Mg pimelates in isotactic polypropylene

<p>The pimelates of the earth-alkaline elements and pimelic acid have been synthesized and studied. All prepared pimelates are crystallohydrates and Ba and Sr pimelates are isotypic. The obtained compounds have been characterized using infrared spectroscopy and X-ray diffraction, and it was found that, near and above the melting temperature of polypropylene, the pimelates of Ba and Sr are crystalline, whereas the ones of Ca and Mg are amorphous. The nucleation activity of these pimelates has been studied in the process of crystallization of polypropylene in non-isothermal conditions and followed by differential scanning calorimetry (at cooling rate <em>V</em>_c= 1–20 K min^–1). It was found that their nucleation activity, even at concentration of 0.1 %, differs considerably with regards to the cooling rate, and they induce different polymorphic composition of the polymer. The nucleation activity was mostly exhibited by Ca pimelate, and when it was used the content of the β crystalline phase (<em>U</em>_β) in polypropylene ranged from 0.90 to 0.94, depending on the cooling rate, compared to 0.18–0.35 when Mg pimelate was used. In the polymer crystallized by using Ba and Sr pimelate as nucleators, <em>U</em>_β ranged from 0.47 to 0.77. Based on the theoretical concepts for nucleation activity of solid substrates, an attempt was made to correlate the structurаl features of the synthesized pimelates with their β-nucleation activity in the process of nonisothermal crystallization of iPP.</p>