scholarly journals Arginine-Induced Self-Assembly of Protoporphyrin to Obtain Effective Photocatalysts in Aqueous Media Under Visible Light

Molecules ◽  
2019 ◽  
Vol 24 (22) ◽  
pp. 4172 ◽  
Author(s):  
Mahmood D. Aljabri ◽  
Nilesh M. Gosavi ◽  
Lathe A. Jones ◽  
Pranay P. Morajkar ◽  
Duong D. La ◽  
...  
Keyword(s):  
Self Assembly ◽  
Aqueous Media ◽  
Protoporphyrin Ix ◽  
Head Group ◽  
X Ray Diffraction ◽  
Visible Radiation ◽  
Enantiomerically Pure ◽  
X Ray ◽  
Ft Ir ◽  
Self Assembled

The fabrication of controlled supramolecular nanostructures via self-assembly of protoporphyrin IX (PPIX) was studied with enantiomerically pure l-arginine and d-arginine, and we have shown that stoichiometry controlled the morphology formed. The nanostructure morphology was mainly influenced by the delicate balance of π-π stacking interactions between PPIX cores, as well as H-bonding between the deprotonated acidic head group of PPIX with the guanidine head group of arginine. PPIX self-assembled with l-/d-arginine to create rose-like nanoflower structures for four equivalents of arginine that were 5–10 μm in length and 1–4 μm diameter. We employed UV-vis, fluorescence spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR) techniques to characterize the resulting self-assembled nanostructures. Furthermore, we investigated the catalytic activity of PPIX and arginine co-assembled materials. The fabricated PPIX–arginine nanostructure showed high enhancement of photocatalytic activity through degradation of rhodamine B (RhB) with a decrease in dye concentration of around 78–80% under simulated visible radiation.

scholarly journals Synthesis of BaTi5O11 by an aqueous co-precipitation method via stable organic titanate precursor

2021 ◽  
pp. 14-14
Author(s):  
Pelin Aktaş
Keyword(s):  
Aqueous Media ◽  
Average Crystallite Size ◽  
Phase Evolution ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Ft Ir ◽  
Scherrer Formula ◽  
Co Precipitation

BaTi5O11 has been widely researched due to its unique microwave properties. Conventionally it is challenging to obtain this compound as a single phase. The BaTi5O11 was synthesized via co-precipitation technique using an aqueous solution of titanium(IV)(triethanolaminato) isopropoxide, barium nitrate and ammonia as precursors which are stable in an aqueous media. The phase evolution, purity, and structure were identified by X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive X-ray (EDX) spectroscopy analysis. The desired BaTi5O11 structure was obtained by calcination at 900?C. Furthermore, the structure is characterized by TGA, FT-IR and Raman studies. The study showed that the particles were between 80 and 120 nm in size and the average crystallite size was determined from the Scherrer formula as 68.1 nm at 900?C.

scholarly journals Different Polyoxometalate Structures Obtained from the Na11H[H(2-x)Bi2W20O70(HWO3)x]·46H2O(x=1.4).

2018 ◽  
Vol 1 (2) ◽  
pp. 93-100
Author(s):  
Suhair Atta
Keyword(s):  
Single Crystal ◽  
Self Assembly ◽  
Multiple Testing ◽  
X Ray Diffraction ◽  
Triclinic Space Group ◽  
X Ray ◽  
Space Groups ◽  
Cell Parameters ◽  
New Family ◽  
Ft Ir

In the supramolecular chemistry world, Polyoxometalates (POMs) are considered as a new family of inorganic molecular containers, construct itself by self-assembly reaction from very small units, to form a cluster with unique structural and properties. three structures reported in this paper - differ in their unit cell parameters and also differ from the well-known - as the result of reaction of the Na11H[H(2- x)Bi2W20O70(HWO3)x]·46H2O (x=1.4) with Ca ion at different pH conditions. These structures are [Ca(H2O)7]2[Na(H2O)2]2[HBi2W20O70(HWO3)].14H2O(1), H2[NH4]10[HBi2W20O70(HWO3)] (2), and [NH4]6[Na(H2O)4]2[Ca(H2O)4]2[W12O42].2H2O (3). The last one is bismuth-free and it is formed through reassembly of the precursor. Full structural characterization was made by multiple testing techniques such as single-crystal X-ray diffraction, UV-visible spectroscopy, FT-IR, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The single-crystal X-ray diffraction results for the three compounds are as follows:(1), Triclinic, space group P-1, while (2) and (3) crystallize in monoclinic space groups C2/m and P21/n respectively.

Preparation and characterization of a new sawdust/MNP/PEI nanocomposite and its applications for removing Pb (II) ions from aqueous solution

2018 ◽  
Vol 78 (12) ◽  
pp. 2469-2480
Author(s):  
Avat Ghasemi ◽  
Mahmoud Reza Sohrabi ◽  
Fereshteh Motiee
Keyword(s):  
Aqueous Solution ◽  
Contact Time ◽  
Adsorption Process ◽  
Aqueous Media ◽  
X Ray Diffraction ◽  
Phase Contact Time ◽  
X Ray ◽  
Langmuir Adsorption ◽  
Ft Ir

Abstract A new sawdust/magnetite nanoparticles/polyethyleneimine (SD/MNP/PEI) nanocomposite was synthesized by grafting polyethyleneimine (PEI) to magnetic sawdust. Features of SD/MNP/PEI were characterized using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), vibrating sample magnetometer (VSM) and scanning electron microscopy (SEM). SD/MNP/PEI was used as an adsorbent for the removal of lead (Pb (II)) from aqueous solution. The effects of independent variables including pH of solution, adsorbent dose and contact time were performed and adsorption isotherms were obtained. Experimental results show that priority effective variables were pH and the amount of nanocomposite, and it was found that the sorption capacity increases with the increasing phase contact time. The adsorption process followed the Langmuir adsorption isotherm. Although SD and SD/MNP do not show a high affinity for the adsorption of Pb (II) in aqueous media, polyethyleneimine cross-linked on SD/MNP showed 40 and 66% increases, respectively, in the adsorption of Pb (II) compared to the SD and SD/MNP. It was found that SD/MNP/PEI removes more efficiently lead ions from aqueous solutions than the SD, SD/MNP. Desorption of the lead from the SD/MNP/PEI was conducted. It was proved that SD/MNP/PEI has excellent properties and can be used as a sorbent of multi-use.

Construction of Highly Pure Nanocrystalline Heteropoly Acid Inside the Channels of Mesoporous Material with the Imprisoned Hydrolyzation Reaction of Heteropoly Acid Etherate

2008 ◽  
Vol 8 (6) ◽  
pp. 3235-3240
Author(s):  
Ying-Ying Gu ◽  
Shu-Yuan Yu ◽  
Ai-Guo Kong ◽  
Chun-Yan Hua ◽  
Han-Ming Ding ◽  
...  
Keyword(s):  
Self Assembly ◽  
Mesoporous Material ◽  
Heteropoly Acid ◽  
Building Blocks ◽  
X Ray Diffraction ◽  
X Ray ◽  
Novel Technique ◽  
Transmission Electron ◽  
Nanocrystalline Particles ◽  
Ft Ir

A novel technique was developed to prepare highly pure heteropoly acid (HPA) nanocrystals inside mesoporous SBA-15 by the imprisoned reaction of HPA etherate and water, which was utilized as a main driving force for the transportation of building-blocks. The transmission electron microscopy, X-ray diffraction, FT-IR spectrum and NMR characterizations unambiguously demonstrate that this method allows the highly pure heteropoly acid nanocrystals with intact Keggin-type structure controlled directionally self-assembly within mesopores of silica SBA-15. Such method may open up a new entry to the highly pure multicomponent nanocrystalline particles inside the cavity of the porous materials.

Novelty of Penicillium camembertii Lipase Supported on Glutaraldehyde Activated-SBA-15 Mesoporous Silica for Mono-Esterification of Bioglycerol in Non-Aqueous Media

2016 ◽  
Vol 14 (4) ◽  
pp. 919-928 ◽  
Author(s):  
Moreshwar P. Hude ◽  
Janusz Kozinski ◽  
Ajay K. Dalai ◽  
Ganapati D. Yadav
Keyword(s):  
Food Industry ◽  
Immobilized Lipase ◽  
Aqueous Media ◽  
Immobilized Enzymes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Penicillium Camembertii ◽  
Ft Ir ◽  
Environmentally Friendly Approach ◽  
Ft Ir Spectroscopy

Abstract Hexagonal mesoporous type silica SBA-15 with pore sizes in the range 5.0–8.3 nm was synthesized using non-ionic triblock copolymer and characterized by Accelerated Surface Area Porosimetry (ASAP), FT-IR spectroscopy, X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Different lipases were immobilized in glutaraldehyde activated mesoporous SBA-15 support. The resulting supported enzymes were shown to be active and stable catalysts for esterification of glycerol with oleic acid to produce monoglyceride (MG) which is commonly used in food industry. Various parameters were studied systematically to study kinetics. MG Synthesis using enzymatic process is an environmentally friendly approach. Enzyme immobilized on SBA-15 showed the best stability and catalytic activity in organic solvents. Out of various lipases studied penicillium camembertii (Lipase G) produced MG efficiently at low temperature. Reusability was studied on immobilized enzymes. Immobilized lipase maintained 90 % of its esterification activity in non-aqueous media even after 4 cycles of use. The selectivity of Lipase G is found to be 98 % for monoacylglyceride.

scholarly journals Controlled Synthesis of BaCO3 Microstructures Using Various Natural Gums - A Biomimetic Approach

2020 ◽  
pp. 453-465
Keyword(s):  
Self Assembly ◽  
Barium Carbonate ◽  
Low Cost ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Carbonates ◽  
Ft Ir ◽  
Biomimetic Approach ◽  
Size And Morphology ◽  
Rational Mechanism

In this study, Barium carbonate microstructures assembled from nanorods are successfully synthesized at room temperature and screw capped method at 100C. The experiments show that the protocol followed for the synthesis of BaCO3 as well as the concentration of various gums used, play an important role in the size and morphology of BaCO3. Here in, we obtained witherite type nanorods aggregates with unusual morphologies via transformation of metal carbonates at different conditions using natural gums as additives. A rational mechanism based on the oriented self-assembly of BaCO3 nuclei is proposed for the formed architectures. The crystals undergo an interesting morphology changes and have been well characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA) and Fourier Transform Infrared spectroscopy (FT-IR) techniques. This method is simple, low-cost and environmentally friendly route for the synthesis of BaCO3 microstructures with altogether different morphologies.

SELF-ASSEMBLY OF BISMUTH SELENIDE TWO-DIMENSIONAL SUPERSTRUCTURE FROM HEXAGONAL NANOSHEETS

2011 ◽  
Vol 04 (03) ◽  
pp. 245-248
Author(s):  
JUNJIE SHEN ◽  
QIAN SUN ◽  
TIEJUN ZHU ◽  
XINBING ZHAO
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Facile Hydrothermal Method ◽  
Lattice Match ◽  
X Ray ◽  
Good Lattice ◽  
Self Assembled ◽  
Scanning Electron

A kind of novel superstructure array composed of hexagonal Bi2Se3 nanosheets were fabricated via a facile hydrothermal method. The structure was characterized by X-ray diffraction and field emission scanning electron micrioscopy. It is suggested that the two dimensional superstructure was self-assembled by sheet-like Bi2Se3 building blocks on naturally-formed Bi2SeO2 precusor template. The present result indicates one promising way in design and growth of self-assembled superstructures by controllable crystal growth from deoxided substrates with good lattice match.

Self-Recognizing π-π Stacking Interactions Designed for the Generation of Ultrastable Mesoporous Hydrogen-Bonded Organic Frameworks

2019 ◽  
Author(s):  
KAIKAI MA ◽  
Peng Li ◽  
John Xin ◽  
Yongwei Chen ◽  
Zhijie Chen ◽  
...  
Keyword(s):  
Pore Size ◽  
Fiber Composite ◽  
Aqueous Media ◽  
Stacking Interactions ◽  
Mustard Gas ◽  
X Ray Diffraction ◽  
X Ray ◽  
Expansion Strategy ◽  
Π Stacking ◽  
Hydrogen Bonded

Creating crystalline porous materials with large pores is typically challenging due to undesired interpen-etration, staggered stacking, or weakened framework stability. Here, we report a pore size expansion strategy by self-recognizing π-π stacking interactions in a series of two-dimensional (2D) hydrogen–bonded organic frameworks (HOFs), HOF-10x (x=0,1,2), self-assembled from pyrene-based tectons with systematic elongation of π-conjugated molecular arms. This strategy successfully avoids interpene-tration or staggered stacking and expands the pore size of HOF materials to access mesoporous HOF-102, which features a surface area of ~ 2,500 m2/g and the largest pore volume (1.3 cm3/g) to date among all reported HOFs. More importantly, HOF-102 shows significantly enhanced thermal and chemical stability as evidenced by powder x-ray diffraction and N2 isotherms after treatments in chal-lenging conditions. Such stability enables the adsorption of dyes and cytochrome c from aqueous media by HOF-102 and affords a processible HOF-102/fiber composite for the efficient photochemical detox-ification of a mustard gas simulant.

scholarly journals Enhancement of Chloroprene/Natural/Butadiene Rubber Nanocomposite Properties Using Organoclays and Their Combination with Carbon Black as Fillers

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1085
Author(s):  
Patricia Castaño-Rivera ◽  
Isabel Calle-Holguín ◽  
Johanna Castaño ◽  
Gustavo Cabrera-Barjas ◽  
Karen Galvez-Garrido ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Black ◽  
High Performance ◽  
Rubber Matrix ◽  
Butadiene Rubber ◽  
X Ray Diffraction ◽  
X Ray ◽  
Rubber Blends ◽  
Ft Ir ◽  
Chloroprene Rubber

Organoclay nanoparticles (Cloisite® C10A, Cloisite® C15) and their combination with carbon black (N330) were studied as fillers in chloroprene/natural/butadiene rubber blends to prepare nanocomposites. The effect of filler type and load on the physical mechanical properties of nanocomposites was determined and correlated with its structure, compatibility and cure properties using Fourier Transformed Infrared (FT-IR), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and rheometric analysis. Physical mechanical properties were improved by organoclays at 5–7 phr. Nanocomposites with organoclays exhibited a remarkable increase up to 46% in abrasion resistance. The improvement in properties was attributed to good organoclay dispersion in the rubber matrix and to the compatibility between them and the chloroprene rubber. Carbon black at a 40 phr load was not the optimal concentration to interact with organoclays. The present study confirmed that organoclays can be a reinforcing filler for high performance applications in rubber nanocomposites.

scholarly journals Electrospun Nanosystems Based on PHBV and ZnO for Ecological Food Packaging

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2123
Author(s):  
Maria Râpă ◽  
Maria Stefan ◽  
Paula Popa ◽  
Dana Toloman ◽  
Cristian Leostean ◽  
...  
Keyword(s):  
Food Packaging ◽  
Spin Trapping ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
Hno3 Solution ◽  
X Ray ◽  
Trapping Method ◽  
Ft Ir ◽  
Doped Zno ◽  
Electron Paramagnetic

The electrospun nanosystems containing poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) and 1 wt% Fe doped ZnO nanoparticles (NPs) (with the content of dopant in the range of 0–1 wt% Fe) deposited onto polylactic acid (PLA) film were prepared for food packaging application. They were investigated by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), antimicrobial analysis, and X-ray photoelectron spectrometry (XPS) techniques. Migration studies conducted in acetic acid 3% (wt/wt) and ethanol 10% (v/v) food simulants as well as by the use of treated ashes with 3% HNO3 solution reveal that the migration of Zn and Fe falls into the specific limits imposed by the legislation in force. Results indicated that the PLA/PHBV/ZnO:Fex electrospun nanosystems exhibit excellent antibacterial activity against the Pseudomonas aeruginosa (ATCC-27853) due to the generation of a larger amount of perhydroxyl (˙OOH) radicals as assessed using electron paramagnetic resonance (EPR) spectroscopy coupled with a spin trapping method.

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