Facile Synthesis of ZSM-5/TiO2/Ni Novel Nanocomposite for the Efficient Photocatalytic Degradation of Methylene Blue Dye

It is critical to develop an appropriate dye degrading technique to preserve the natural environment and human health owing to the dangerous water pollution caused by effluent dyes. So, in this work, a ZSM-5/TiO₂/Ni photocatalyst was synthesized as a novel composite and used for degrading methylene blue dye in the solution. The sol–gel approach was used to immobilize titanium dioxide nanoparticles on the ZSM-5 surface, and the resulting photocatalyst was then modified using nickel nanoparticles to improve its photocatalytic performance. The nanocomposite was characterized using different tools such as FE-SEM, EDX, XRD, FT-IR, TGA, and UV–Vis spectrophotometer. The XRD confirmed that the synthesized composite has the characteristic TiO₂ peaks. FE-SEM images of ZSM-5 exhibited rough, uneven, and jagged surfaces. A distinct shift in the morphology of the surface resulted when titanium dioxide was fully immobilized on the surface of ZSM-5. Shape complexity and surface roughness of the particles are elevated in the case of the ZSM-5/TiO₂/Ni nanocomposite. The maximum % degradation of 50 mL of 15 mg/L of methylene blue dye is 99.17% and achieved at pH?=?8, irradiation time?=?140 min, and photocatalyst dosage?=?0.05 g. The synthesized composite can be regenerated and reused several times without losing its efficacy.

     

Synthesis of Co3O4 @ Organo/Polymeric Bentonite Structures as Environmental Photocatalysts and Antibacterial Agents for Enhanced Removal of Methyl Parathion and Pathogenic Bacteria

Two green nanocomposites of Co₃O₄ decorated CTAB/bentonite (Co@CT/BE) and chitosan/bentonite (Co@CH/BE) were synthesized as enhanced and environmental photocatalysts and antibacterial agents. As photocatalysts, the products were applied in the effective oxidation of toxic methyl parathion pesticide (MP) in wastewater under a visible light source. The application of Co@CH/BE (0.02 g) resulted in the complete oxidation of MP (50 mg/L) after 40 min and complete mineralization after 60 min. while the complete oxidation and mineralization of MP (50 mg/L) by Co@CT/BE was recognized after 75 min and 100 min, respectively. The Co@CH/BE composite is of higher activity than Co@CT/BE and can cause complete oxidation for MP at high concentrations up to 100 mg/L after 75 min. The oxidation pathway was illustrated considering the existence of the hydroxyl radicals as the active oxidizing species and the identified secondary organic compounds during the oxidation tests. The detected intermediate converted into end products of CO₂ and inorganic anions of SO₄^?2, NO₃^?, and PO₄^?3 at the final stages of the oxidation processes. As antibacterial agents, the two composites exhibit considerable inhabitation zones of about 20 mm against both the Gram-positive Staphylococcus aureus and Gram-negative bacterium Vibrio Sp. The synthetic Co@CH/BE showed the best antibacterial properties with 200 μg/mL as minimum inhibitory against Staphylococcus aureus.

     

Correction to: Synthesis of Co3O4 @ Organo/Polymeric Bentonite Structures as Environmental Photocatalysts and Antibacterial Agents for Enhanced Removal of Methyl Parathion and Pathogenic Bacteria

Journal of Inorganic and Organometallic Polymers and Materials -     

Green Nanoarchitectonics of Cu/Fe3O4 Nanoparticles Using Helleborus niger Extract Towards an Efficient Nanocatalyst,Antioxidant and Anti-lung Cancer Agent

Biogenic nanoarchitectured magnetic materials have drawn serious attention throughout the last decade. We have attempted the Helleborus niger flower extract functionalized and templated biogenic synthesis of Cu nanoparticles supported Fe₃O₄ as a likewise novel material. The plant phytomolecules were deployed as a non-toxic sustainable reductant and an outstanding capping agent to stabilize the synthesized NPs. The synthesized Cu/H.niger@Fe₃O₄ nanocomposite was undergone comprehensive characterizations through Fourier transformed infrared spectroscopy (FT-IR), electron microscopy (SEM and TEM), energy dispersive X-ray spectroscopy (EDX), elemental mapping, vibrating sample magnetometer (VSM), X-ray diffraction (XRD) and inductively coupled plasma (ICP) techniques. The material was catalytically explored in the synthesis of diverse pyrano[3,2-c]chromene derivatives by coupling 4-hydroxycoumarin, malononitrile and a range of aldehydes in hot water when it afforded excellent yields. Based on its core magnetism, the catalyst was easily recovered using a magnet and reused for 8 successive times without considerable loss in catalytic activity. After the chemical application, the synthesized Cu/H.niger@Fe₃O₄ nanocomposite was engaged in biological assays like study of anti-oxidant properties by DPPH mediated free radical scavenging test using BHT as a reference molecule. Thereafter, on having a significant IC₅₀ value in radical scavenging assay, we extended the bio-application of the desired nanocomposite in anticancer study of A549 and H358 human lung cell lines in-vitro through MTT assay. The cell viability of malignant lung cell line reduced dose-dependently in the presence of desired nanocomposite. So, these results suggest that synthesized Cu/H.niger@Fe₃O₄ as a chemotherapeutic nanomaterial have a suitable anticancer activity against lung cell lines.

     

Comparative study on oxidative decomposition behavior of vegetable oils and its correlation with iodine value using thermogravimetric analysis

A comparative study of oxidative decomposition behavior of a wide range of vegetable oils and its correlation to iodine value (IV) using thermogravimetric analysis (TGA) was described. The oxidative decomposition of saturated fatty acids shows weight loss before 385 degrees C while oxidative decomposition of unsaturated fatty acids shows lower rate of weight loss (dWt/dt) compared to saturated fatty acids due to the oxidation process ('up taking ' of oxygen) involving breaking down of double bond to form primary and secondary oxidation products, which leads to some weight gain in the sample before being decomposed. The relative differences in the dWt/dt (%/min) of the both fatty acids give different decomposition steps in TGA thermogram, enabling IV to be determined through the percentage weight loss of saturated fatty acids per 100% of total sample weight (excluding weight loss from moisture and volatile compounds). Therefore, TGA method can be used as an alternative method for IV determination with no sample pre-dilution and solvent consumption. Using the TGA methods, good correlation (r = 0.9889) with standard AOCS method was achieved.     

Synthesis and characterization of biodegradable poly(ester‐urethanes) based on bacterial poly(R‐3‐hydroxybutyrate)

A series of poly(R‐3‐hydroxybutyrate)/poly(ε‐caprolactone)/1,6‐hexamethylene diisocyanate‐segmented poly(ester‐urethanes), having different compositions and different block lengths, were synthesized by one‐step solution polymerization. The molecular weight of poly(R‐3‐hydroxybutyrate)‐diol, PHB‐diol, hard segments was in the range of 2100–4400 and poly(ε‐caprolactone)‐diol, PCL‐diol, soft segments in the range of 1080–5800. The materials obtained were investigated by using differential scanning calorimetry, wide angle X‐ray diffraction and mechanical measurements. All poly(ester‐urethanes) investigated were semicrystalline with T_m varying within 126–148°C. DSC results showed that T_g are shifted to higher temperature with increasing content of PHB hard segments and decreasing molecular weight of PCL soft segments. This indicates partial compatibility of the two phases. In poly(ester‐urethanes) made from PCL soft segments of molecular weight (M_n ≥ 2200), a PCL crystalline phase, in addition to the PHB crystalline phase, was observed. As for the mechanical tensile properties of poly(ester‐urethane) cast films, it was found that the ultimate strength and the elongation at the breakpoint decrease with increasing PHB hard segment content. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 703–718, 2002     

Rheology of concentrated solutions of hyperbranched polyesters

The solution rheology of different generations of hyperbranched polyesters in N‐methyl‐2‐pyrrolidinone (NMP) solvent was examined in this study. The solutions exhibited Newtonian behavior over a wide range of polyester concentrations. Also, the relative viscosities of poly(amidoamine) (PAMAM) dendrimers in ethylenediamine were compared with those of the hyperbranched polyesters in NMP. Both types of dendritic polymers have relative viscosities that are exponential functions of their molar fraction in solution. The slopes of these relative viscosity curves show a linear relationship with respect to the generation number. PAMAM dendrimers have the greater slopes for each generation, reflecting their relatively larger intrinsic viscosity values.     

Low molecular weight oligo-β-hydroxybutyric acids and 3-hydroxy-N-phenethyl-butyramide – new products from microorganisms

Summary A new group of low-molecular weight channel-forming oligo(hydroxybutyric acids) (cPHBs, 1 with n = 8–30; main component MW ≈ 1300 dalton) was isolated from microorganisms of different origin. Inclusion bodies were electron-microscopically visible in cells in the state of autolysis, not in cells in the exponential phase of growth. cPHB and high-molecular poly(l3-hydroxybutyric acid) (sPHB) is cleaved by phenylethylamine and forms the corresponding monomeric hydroxybutyramide and – under drastic conditions, the crotylamide. One of these compounds, the 3-hydroxy-N-phenethyl-butyramide (5), was isolated as a new natural product now. Received: 28 March 2002/Revised version: 26 July 2002/ Accepted: 26 July 2002 RID="*" ID="*"Marine Bakterien, XVII. XVI: R.P. Maskey, R.N. Asolkar, E. Helmke, and H. Laatsch, Chalcomycin B, a new antibiotic from a marine Streptomyces sp. B7064. J. Antibiot., submitted 2002 Correspondence to Hartmut Laatsch, e-mail: hlaatsc@gwdg.de, Fax: +49-551-399660     

Impacts of conservation agriculture on soil aggregation and aggregate-associated N under an irrigated agroecosystem of the Indo-Gangetic Plains

We evaluated impacts of conservation agriculture (zero tillage, bed planting and residue retention) on changes in total soil N (TSN) and aggregate-associated N storage in a sandy loam soil of the Indo-Gangetic Plains. Cotton (Gossypium hirsutum) and wheat (Triticum aestivum) crops were grown during the first 3 years (2008–2011) and in the last year, maize (Zea mays) and wheat were cultivated. Results indicate that after 4 years the plots under zero tillage with bed planting (ZT-B) and zero tillage with flat planting (ZT-F) had 15 % higher TSN concentrations than conventional tillage and bed planting plots (CT-B) (0.63 g kg^?1 soil) in the 0–5 cm soil layer. CT-B plots had lower soil bulk density that ZT plots in that layer. Plots under ZT-B (0.57 Mg ha^?1) contained 20 % higher TSN stock in the 0–5 cm soil layer than CT-B plots (0.48 Mg ha^?1). However, tillage had no impact on TSN concentration or stock in the sub-surface (5–15 and 15–30 cm) soil layers. Thus, in the 0–30 cm soil layer, ZT-B plots contained 6 and 5 % higher (P > 0.05) TSN stock compared with CT-B (2.15 Mg N ha^?1) and CT-F (2.19 Mg N ha^?1) plots respectively after 4 years. Plots that received cotton/maize + wheat residue (C/M + W RES) contained 16 % higher TSN concentration than plots with residues removed (N RES; 0.62 g kg^?1 soil) in the surface (0–5 cm) layer. Plots with only cotton/maize residue (C/M RES) or only wheat residue (W RES) retention/incorporation had similar TSN concentrations and stocks in the subsurface layer. Plots under ZT-B also had more macroaggregates (0.25–8 mm) and greater mean weight diameter with lower silt + clay sized particles than CT-B plots in that layer. A greater proportion of large macroaggregates (2–8 mm) in the plots under C/M + W RES compared with N RES were observed. In the 5–15 cm soil layer ZT-B and C/M + W RES treated plots had more macroaggregates and greater mean weight diameter than CT-B and N RES treated plots, respectively. Because of the greater amount of large aggregates, plots under ZT-B and C/M + W RES had 49 and 35 % higher large macroaggregate-associated N stocks than CT-B (38 kg TSN ha^?1) and N RES (40 kg TSN ha^?1) plots, respectively, in the 0–5 cm soil layer, although aggregates had similar TSN concentrations in all plots. Both tillage and residue retention had greater effects on aggregate-associated N stocks in the 5–15 cm layers. In addition to N content within large macroaggregates, small macroaggregate-associated N contents were also positively affected by ZT-B and C/M + W RES. Tillage and residue retention interaction effects were not significant for all parameters. Thus, the adoption of ZT in permanent beds with crop residue addition is a better management option for improvement of soil N (and thus possibly a reduced dose of fertilizer N can be adopted in the long run), as the management practice has the potential to improve soil aggregation with greater accumulation of TSN within macroaggregates, and this trend would likely have additive effects with advancing years of the same management practices in this region.