scholarly journals Adsorption of Cellulase on Wrinkled Silica Nanoparticles with Enhanced Inter-Wrinkle Distance

Nanomaterials ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1799
Author(s):  
Aniello Costantini ◽  
Virginia Venezia ◽  
Giulio Pota ◽  
Aurelio Bifulco ◽  
Valeria Califano ◽  
...  
Keyword(s):  
Silica Nanoparticles ◽  
Morphological Characterization ◽  
Operational Stability ◽  
Successful Outcome ◽  
Glucose Yield ◽  
Transmission Electron ◽  
Ft Ir ◽  
Immobilized Cellulase

Mesoporous silica materials offer a unique opportunity for enzyme immobilization thanks to their properties, such as tuneable pore size, large surface area and easy functionalization. However, a significant enhancement of cellulase enzyme activity entrapped inside the silica pores still represents a challenge. In this work, we immobilized cellulase by adsorption on wrinkled silica nanoparticles (WSNs), obtaining an active and stable biocatalyst. We used pentanol as co-solvent to synthesize WSNs with enhanced inter-wrinkle distance in order to improve cellulase hosting. The physical-chemical and morphological characterization of WSNs and cellulase/WSNs was performed by thermogravimetric (TG), Fourier transform infrared (FT-IR), and transmission electron microscopy (TEM) analyses. The obtained results showed that this matrix generates a favourable microenvironment for hosting cellulase. The results of the catalytic assays and operational stability confirmed the key role of size, morphology and distribution of the pores in the successful outcome of the cellulase immobilization process. The immobilization procedure used allowed preserving most of the secondary structure of the enzyme and, consequently, its catalytic activity. Moreover, the same value of glucose yield was observed for five consecutive runs, showing a high operational stability of the biocatalyst.

scholarly journals In Situ IR Characterization of CO Interacting with Rh Nanoparticles Obtained by Calcination and Reduction of Hydrotalcite-Type Precursors

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
F. Basile ◽  
I. Bersani ◽  
P. Del Gallo ◽  
S. Fiorilli ◽  
G. Fornasari ◽  
...  
Keyword(s):  
Crystal Size ◽  
Liquid Nitrogen Temperature ◽  
Transmission Electron ◽  
In Situ Ir ◽  
Ft Ir ◽  
Co Disproportionation ◽  
Ft Ir Spectroscopy

Supported Rh nanoparticles obtained by reduction in hydrogen of severely calcined Rh/Mg/Al hydrotalcite-type (HT) phases have been characterized by FT-IR spectroscopy of adsorbed CO [both at room temperature (r.t.) and nominal liquid nitrogen temperature] and Transmission Electron Microscopy (TEM). The effect of reducing temperature has been investigated, showing that Rh crystal size increases from 1.4 nm to 1.8 nm when the reduction temperature increases from 750°C to 950°C. The crystal growth favours the formation of bridged CO species and linear monocarbonyl species with respect to gem-dicarbonyl species; when CO adsorbs at r.t., CO disproportionation occurs on Rh and it accompanies the formation of RhI(CO)2. The role of interlayer anions in the HT precursors to affect the properties of the final materials has been also investigated considering samples prepared from silicate-instead of carbonate-containing precursors. In this case, formation of RhI(CO)2 and CO disproportionation do not occur, and this evidence is discussed in terms of support effect.

Synthesis and Characterization of Thiol- and Carboxyl-Functionalized Mesoporous Silica Nanoparticles

2017 ◽  
Vol 1142 ◽  
pp. 220-224 ◽  
Author(s):  
Wan Xia Wang ◽  
Yu Wang ◽  
Hua Meng Gong ◽  
Hong Hao Sun ◽  
Ming Xing Liu
Keyword(s):  
Electron Microscopy ◽  
Mesoporous Silica ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Spherical Shape ◽  
Synthesis And Characterization ◽  
Functionalized Mesoporous Silica ◽  
Transmission Electron ◽  
Ft Ir

The purpose of this article is to synthesize the thiol-and carboxyl-bifunctionalized mesoporous silica nanoparticles (CMS-SH-COOH). CMS-SH-COOH was successfully synthesized by co-condensation and post-grafting methods. Moreover, the particle size and structural properties of CMS-SH-COOH were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS) and Fourier transform infrared spectroscopy (FT-IR). The obtained results indicated that the CMS-SH-COOH presented a uniform spherical shape with a wormhole arrangement of the mesopores and a relatively narrow paticle distribition. Therefore, the CMS-SH-COOH might be a great potential carrier for the drug delivery system in the future.

One Step Synthesis and Characterization of Zirconia-Graphene Composites

2012 ◽  
Vol 600 ◽  
pp. 174-177 ◽  
Author(s):  
Jian Fei Xia ◽  
Zong Hua Wang ◽  
Yan Zhi Xia ◽  
Fei Fei Zhang ◽  
Fu Qiang Zhu ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Composite ◽  
Transmission Electron ◽  
One Step ◽  
Ft Ir ◽  
Xrd Techniques

Zirconia-graphene composite (ZrO2-G) has been successfully synthesized via decomposition of ZrOCl2•6H2O in a water-isopropanol system with dispersed graphene oxide (GO) utilizing Na2S as a precursor could enable the occurrence of the deposition of Zr4+ and the deoxygenation of GO at the same time. Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD) techniques were used to characterize the samples. It was found that graphene were fully coated with ZrO2, and the ZrO2 existing in tetragonal phase, which resulted in the formation of two-dimensional composite.

Facile Synthesis of Cu2O Nanocubes in Triblock Copolymer Solutions

2007 ◽  
Vol 121-123 ◽  
pp. 275-278
Author(s):  
Jin Hua Jiang ◽  
Qiu Ming Gao
Keyword(s):  
Triblock Copolymer ◽  
Solar Spectrum ◽  
Blue Shift ◽  
Edge Length ◽  
Promising Candidate ◽  
Organic Species ◽  
Transmission Electron ◽  
Ft Ir ◽  
Average Edge Length

Cuprous oxide and related materials in nanosizes are of much interest and investigated extensively recently. It is reported here that cubic Cu2O nanocubes were synthesized successfully in aqueous solutions at room temperature in air condition. Copper (II) salts in water were reduced with ascorbate acid in air, using the nonionic pluronic amphiphilic triblock copolymer EO20PO70EO20 (P123) as the template-directing and protecting agent. The average edge length of the cubes varied from 50 to 100 nm. Transmission electron microscopy (TEM) has been used for the shape and structural characterization of the obtained Cu2O nanocubes. The UV-Vis spectra showed an obvious blue-shift (0.53 eV), compared to the band gap of the bulk Cu2O crystal, which makes it a promising candidate in solar energy conversion since this sample can make use of higher energy visible rays of solar spectrum. In the FT-IR spectra the peak of Cu-O bond for the Cu2O is clearly distinguished and several weak peaks of the C-H, C-C and C=O bonds for the organic species can also be detectable, implying a little P123 residua in the products. The effect of the triblock copolymer P123 on the growth of the Cu2O nanocubes is discussed.

Bentonite-Based Organoclays as Innovative Flame Retardants Agents for SBS Copolymer

2008 ◽  
Vol 8 (12) ◽  
pp. 6316-6324 ◽  
Author(s):  
M. Comes Franchini ◽  
P. Fabbri ◽  
A. Frache ◽  
G. Ori ◽  
M. Messori ◽  
...  
Keyword(s):  
Flame Retardants ◽  
Morphological Characterization ◽  
Tem Analysis ◽  
Important Functional Property ◽  
Octadecyltrimethylammonium Bromide ◽  
Nitrogen Containing Compounds ◽  
Styrene Butadiene ◽  
Heat Released

Two organophilic bentonites, based on nitrogen-containing compounds, have been synthesised via ion exchange starting from pristine bentonite with octadecyltrimethylammonium bromide (OTAB) and with synthetic melamine-derived N2,N4-dihexadecyl-1,3,5-triazine-2,4,6-triamine (DEDMEL). The chemical and morphological characterization of the organoclays was based on XRD, TEM, Laser Granulometry, X-Ray Fluorescence and CEC capacity. Copoly(styrene-butadiene-styrene)-nanocomposites (SBS-nanocomposites) were obtained by intercalation of the SBS-copolymer into these new organoclays by melt intercalation method. XRD and TEM analysis of the organoclays and of the micro/nano-composites obtained are presented. The effect of the organoclays on the SBS-nanocomposite's flammability properties was investigated using cone calorimeter. An encouraging decrease of 20% in the peak heat released rate (PHRR) has been obtained confirming the important role of melamine's based skeleton and its derived organoclays to act as effective fire retardants and for the improvement of this important functional property in SBS copolymers.

STRUCTURAL AND MORPHOLOGICAL CHARACTERIZATION OF GOLD NANOPARTICLES BY TEM AND DIGITAL CIS TECHNIQUE

2010 ◽  
Vol 09 (05) ◽  
pp. 399-406 ◽  
Author(s):  
A. A. EL-DALY
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Au Nanoparticles ◽  
Morphological Characterization ◽  
Particle Sizes ◽  
Rigid Surface ◽  
Gold Nanocrystals ◽  
Driving Mechanisms ◽  
Transmission Electron

In this paper, we report a convenient and informative procedure for detecting the morphology and surface structure of individual gold nanocrystals using digital Crystal Image Software (CIS) processing of transmission electron microscopy (TEM) image, which comprises coalescence phenomena of these nanoparticles. The results show that the internal structure of Au nanoparticles has a core of gold atoms arranged as a Marks decahedron, surrounded by additional gold–organic compound layers forming a rigid surface layer, and its outer layer comprises four staple motif bridge molecules that resemble handles, formed an unusual pattern. The obtained results improved our understanding of the basics of the coalescence phenomena such as the driving mechanisms acting at different particle sizes. However, these discrete natures of the nanoparticles will assist in the understanding of principles of nanocore assembly and opens a new window for nanoparticles chemistry.

Structural and Morphological Characterization of Ultrathin Films of an Asymmetric Polydiacetylene

1996 ◽  
Vol 440 ◽  
Author(s):  
H. C. Wang ◽  
D. W. Cheong ◽  
J. Kumar ◽  
C. Sung ◽  
S. K. Tripathy
Keyword(s):  
Second Harmonic ◽  
Morphological Characterization ◽  
Lb Films ◽  
Force Microscopy ◽  
Langmuir Blodgett ◽  
Glass Substrates ◽  
Atomic Force ◽  
Transmission Electron ◽  
Air Water Interface

AbstractA soluble, asymmetrically substituted polydiacetylene, poly(BPOD), has been reported to form stable monolayers at the air-water interface by the Langmuir-Blodgett (LB) technique [2]. Preformed polydiacetylene has been deposited onto hydrophobic substrates as multilayers to form second order nonlinear optical thin films. Second harmonic generation was found to increase with the number of layers. From previous atomic force microscopy (AFM) studies backbone orientation along the dipping direction with an interchain spacing of about 5 A° was indicated [2].The film morphology and preferential molecular orientation of these LB films are further investigated by transmission electron microscopy (TEM). A specifically tailored sample preparation method for the ultrathin LB films was used. Multilayer films were deposited on hydrophobic collodion covered glass substrates for this purpose. Electron diffraction was employed to study the crystalline organization of mono and multilayers of LB films as well as cast films.

Structure and Properties of Modifier for Heat Transfer Printing on Cotton Fabric

2011 ◽  
Vol 331 ◽  
pp. 426-429
Author(s):  
Yi Mu ◽  
Lan Wang ◽  
Ming Hua Wu ◽  
Jun Xiong Lin
Keyword(s):  
Heat Transfer ◽  
Spherical Shape ◽  
Decomposition Temperature ◽  
Polymerization Process ◽  
Structure And Properties ◽  
Transfer Printing ◽  
Transmission Electron ◽  
Ft Ir ◽  
Regular Spherical Shape

Modifier for heat transfer printing on cotton fabrics was prepared by semi-continuous emulsion polymerization process with butyl acrylate (BA), styrene (St), acrylonitrile (AN) and cross-linking monomer. FT-IR characterization of modifier groups showed that individual monomer well carried out polymerization. Transmission electron microscopy (TEM) photos demonstrated that latex particles had regular spherical shape and uniform distribution. TGA curves indicated that thermal decomposition temperature of modifier was 439 oC. As for the transfer printing products had good colour fastness, high transfer rate and no formaldehyde.

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