scholarly journals Immobilization ofAspergillus Oryzae β-Galactosidase on Newly Prepared Porous Poly(GMA-ST)

2011 ◽  
Vol 8 (3) ◽  
pp. 1232-1237 ◽  
Author(s):  
Sun Sufang ◽  
Xu Xiaobing
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Enzyme Activity ◽  
Kinetic Data ◽  
Immobilized Enzyme ◽  
Lauryl Alcohol ◽  
Optimum Conditions ◽  
Porous Poly ◽  
Scanning Electron

The macroporous and reactive carriers polyGMA-ST was synthesized simultaneously with a mixture of cyclohexanol and lauryl alcohol as liquid pore-forming agents and nano-calcium carbonate as solid one by bulk copolymerization. After the polymer was smashed, particles with diameters ranging 0.15 mm to 0.30 mm were taken as the carrier and the Scanning electron microscopy (SEM) micrographs were done to characterize its surface structure. Under the optimum conditions,β-galactosidaseAspergillus oryzaewas immobilized on the supporter obtained above, its enzyme activity could reach to 535.11U/g dry carrier and the activity recovery of the immobilizedβ-galactosidase was 79.63%. Meanwhile, the basic property and the kinetic data of the immobilized enzyme were determined and compared with those of the free enzyme and satisfactory results were obtained in pH stability, thermal stability and operational stability. The conclusion obtained here indicated that the ploy(GMA-co-ST) prepared concurrently with liquid and solid porogen was suitable to immobilize enzyme.

scholarly journals A Novel Method to Prepare PolyGMA and its Application to Immobilization of β-Galactosidase

2009 ◽  
Vol 6 (4) ◽  
pp. 1071-1076
Author(s):  
Sun Sufang ◽  
Dong Lingyun
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Scanning Electron Microscopy ◽  
Enzyme Activity ◽  
Calcium Carbonate ◽  
Surface Structure ◽  
Epoxy Group ◽  
Optimum Conditions ◽  
Novel Method ◽  
Scanning Electron

The reactive, macroporous and massive epoxy group containing polyGMA was synthesized simultaneously with methanol aqueous solution and nano-calcium carbonate as porogen by bulk copolymerization. After the polymer was smashed, particles with diameters in the range of 0.30 to 0.45 mm were taken as the carrier and the scanning electron microscopy (SEM) micrographs were done to characterize its surface structure. Under the optimum conditions, β-galactosidase was immobilized on the supporter obtained above and the enzyme activity bound per gram drier carrier could attained up to 77.33％, which was much higher than that bound on the carrier prepared by only using methanol aqueous solution as porogen. The conclusion obtained indicated that the ployGMA prepared concurrently with liquid and solid porogen was more suitable to immobilize enzyme because of the much more porous surface structure obtained.

scholarly journals Polymeric Composites Based on Polyurea Matrix Reinforced with Carbon Nanotubes

2017 ◽  
Vol 54 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Maria Adina Vulcan ◽  
Celina Damian ◽  
Paul Octavian Stanescu ◽  
Eugeniu Vasile ◽  
Razvan Petre ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Tensile Tests ◽  
Mechanical Analysis ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes ◽  
Scanning Electron

This paper deals with the synthesis of polyurea and its use as polymer matrix for nanocomposites reinforced with multi-walled carbon nanotubes (MWCNT). Two types of materials were obtained during this research, the first cathegory uses the polyurea as matrix and the second one uses a mixture between epoxy resin and polyurea. The nanocomposites were characterized by Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA), Scanning Electron Microscopy (SEM) and Tensile Tests .The elastomeric features of nanocomposites were highlighted by the results which showed low value of Tg. Also higher thermal stability with ~40oC compared with commercial products (M20) were observed, but lower mechanical properties compared to neat polyurea.

Effect of Anthracite on Preparation of Ceramsite Using Red Mud

2013 ◽  
Vol 467 ◽  
pp. 3-7
Author(s):  
Hui Fen Yang ◽  
Lin Fei Lu ◽  
Bei Ping Jiang ◽  
Jin Long Zhang
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Bulk Density ◽  
Red Mud ◽  
Absorption Rate ◽  
Weight Ratio ◽  
Foaming Agent ◽  
Thermal Stability Of ◽  
Scanning Electron

Based on analyzing of chemical composition, mineral composition and thermal stability of red mud, preparation of ceramisite, using anthracite added as foaming agent, was investigated. Internal structure was observed by scanning electron microscopy (SEM). The results showed the bulk density of ceramisite was obviously reduced by anthracite added. The ceramisite with bulk density of 1.30g/cm3, water absorption rate£ ̈WAR£©of 2.98% and cylinder compressive strength £ ̈CCS£©of 9.48 MPa was obtained when weight ratio of red mud/waste glass/bentonites/anthracite was at 73:15:11:1. Majority of porosity in ceramisite was closed based on SEM. The porosity of ceramisite was much higher when anthracite was added as foaming agent than only calcite in red mud was used as foaming agent. The bulk density of the former was lower than that of the latter.

scholarly journals Curing kinetics of phenolphthalein based polyphosphazene towards thermal stability and flame retardancy of polybenzoxazine

RSC Advances ◽  
2019 ◽  
Vol 9 (54) ◽  
pp. 31583-31593 ◽  
Author(s):  
Ling Zhao ◽  
Chunxia Zhao ◽  
Min Wu ◽  
Yuntao Li ◽  
Hui Li ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Fourier Transform ◽  
Flame Retardancy ◽  
Curing Kinetics ◽  
Ultrasound Assisted ◽  
Kinetics Of ◽  
Polymerization Method ◽  
Scanning Electron

Phenolphthalein type polyphosphazene (PZPT) microspheres were synthesized by an ultrasound assisted precipitation polymerization method, and their structures were confirmed by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy.

Characterization of PET-Silver Nanocomposite Filaments

2018 ◽  
Vol 930 ◽  
pp. 224-229
Author(s):  
Marcos Antônio Guerra ◽  
Jeferson Prado Swerts ◽  
Mei Abe Funcia ◽  
Neide Aparecida Mariano ◽  
Maria Gabriela Nogueira Campos
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Silver Nanoparticles ◽  
Addition Method ◽  
X Ray ◽  
Silver Nanocomposite ◽  
Thermal Stability Of ◽  
Scanning Electron

Polyethylene terephthalate (PET) fiber is a very versatile fiber that can be produced with different properties, such as antimicrobial activity. This study aims to synthesize antimicrobial PET filaments incorporated with silver nanoparticles immobilized in silica (NPAg-Si) by bulk additive method. Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray (EDX) characterized the obtained filaments at concentrations (w/w) of 0.008%, 0.016%, 0.032%, 0.047% and 0.063% NPAg-Si, in order to identify the nanoparticles and analyze their dispersion in the polymeric matrix. Moreover, thermogravimetric analysis (TGA) was carry out to confirm the presence and concentration of the silver nanoparticles in the filaments as well as the thermal stability of the nanocomposites. The bulk addition method was efficient to produce PET-Silver filaments with silver nanoparticles homogeneously dispersed in the PET matrix.

Synthesis and Thermal Stability of Nontransformable Tetragonal (ZrO2)0.96(REO1.5)0.04 (Re=Sc3+, Y3+) Nanocrystals

2013 ◽  
Vol 334-335 ◽  
pp. 60-64 ◽  
Author(s):  
Mohammad Reza Loghman-Estark ◽  
Reza Shoja Razavi ◽  
Hossein Edris
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Sol Gel ◽  
Average Diameter ◽  
X Ray ◽  
Transmission Electron ◽  
20 Nm ◽  
Thermal Stability Of ◽  
Scanning Electron

Scandia, yttria doped zirconia ((ZrO2)0.96(REO1.5)0.04(RE=Sc3+, Y3+)) nanoparticles were prepared by the modified sol-gel method. The microstructure of the products was characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Raman spectroscopy. Thermal stabillity of SYSZ nanocrystals were also investigated. The SYSZ nanocrystals synthesized with EGM:Zr+4mole ratio 4:1, calcined at 700°C, have average diameter of ~20 nm.

Synthesis and Characterization of Andalusite/Polyaniline Composites

2011 ◽  
Vol 675-677 ◽  
pp. 295-298
Author(s):  
Liang Shao ◽  
Jian Hui Qiu ◽  
Ming Zhu Liu ◽  
Hui Xia Feng ◽  
Guo Hong Zhang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Synthesis And Characterization ◽  
Conducting Phase ◽  
Polyaniline Composites ◽  
Inorganic Substrate ◽  
Thermal Stability Of ◽  
Scanning Electron

New types of conducting composites using andalusite as an inorganic substrate and polyaniline as the conducting phase were prepared. The composites exhibited conductivities in the 0.14-2.08 S/cm range, depending on the amount of polyaniline. The thermal stability of andalusite/polyaniline composites were studied by thermogravimetric analysis. The resulting composites were also characterized by using FTIR spectroscopy and scanning electron microscopy.

Effects of Polyaniline Doped by Different Acids on Thermal Stability of Epoxy Resin

2010 ◽  
Vol 160-162 ◽  
pp. 1405-1408 ◽  
Author(s):  
Qing Ming Jia ◽  
Shao Yun Shan ◽  
Li Hong Jiang ◽  
Ya Ming Wang
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Sulfuric Acid ◽  
Epoxy Resin ◽  
Inert Atmosphere ◽  
Pani Nanofibers ◽  
Thermal Stability Of ◽  
Scanning Electron

Polyaniline(PANI) nanofibers were firstly prepared by rapid mixture method, EP/PANI nanocomposite was obtained by in-situ adding the PANI nanofibers to epoxy resin(EP). Scanning electron microscopy(SEM) proves that the type of doped acids has a little effect on the morphologies of PANI, and the PANI doped by different acids present nanofiber structures with the diameter of about 50 nm. The thermal behaviour of EP/PANI nanocomposites were investigated in detail by using a dynamic rate mode of thermogravimetric analyser (TGA) in inert atmosphere, and the results show that the PANI nanofibers obviously improve thermal stability of pure EP. Compared with EP/PANI doped by nitric acid or sulfuric acid, EP/PANI doped by phosphoric acid has best thermal stability.

An easy approach to fabricating HgS/chitosan nanocomposite films and their ability to sense triethylamine

2014 ◽  
Vol 34 (4) ◽  
pp. 339-344 ◽  
Author(s):  
Shan Wang ◽  
Minyan Zheng
Keyword(s):  
Electron Microscopy ◽  
Thermal Stability ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Fluorescence Emission ◽  
Nanocomposite Films ◽  
Scanning Calorimetry ◽  
Sem Image ◽  
Thermal Stability Of ◽  
Scanning Electron

Abstract A chitosan (CS)–HgS nanocomposite was synthesized by a simulating biomineralization method. The effect of HgS nanoparticles on the physical properties of the composite was studied by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). The glass transition temperature (Tg) of the composite was 22°C higher than that of CS. The thermal stability of the composite was higher than that of CS, which was evidenced by the shift of onset temperature of degradation by 22°C as measured by DSC. The SEM image of the HgS/CS nanocomposite film shows that the nanoparticle size was 100 nm. The fluorescence emission of nanocomposite films was found to be very sensitive to the presence of triethylamine; even a small amount of triethylamine dramatically increased emissions. By contrast, emission was hardly affected by other common ions in water. The films are predicted to have the potential to be developed into excellent sensing films for triethylamine.

Conformation and Activity of Sol-Gels Encapsulated Cross-Linked Enzyme Aggregates of Lipase from Burkholderia cepacia

2011 ◽  
Vol 291-294 ◽  
pp. 614-620 ◽  
Author(s):  
Yun Liu ◽  
Yu Ling Guo ◽  
Da Wei Chen ◽  
Cheng Peng ◽  
Yun Jun Yan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Enzyme Activity ◽  
Burkholderia Cepacia ◽  
High Stability ◽  
Sol Gel ◽  
Specific Enzyme ◽  
Specific Enzyme Activity ◽  
Cd Studies ◽  
Scanning Electron

Cross-linked enzyme aggregates (CLEAs) of lipase from Burkholderia cepacia (BCL) were explored using different precipitants and different amount of glutaraldehyde as cross-linkers. The ‘fresh’ and ‘mature’ CLEAs-BCL was successfully encapsulated with sol-gel support. The latter showed the highest specific enzyme activity, which was 1.7 and 13.2-fold over CLEAs-BCL before encapsulation with sol-gel and free BCL, respectively. It performed high transesterification activity with the biodiesel yield of 88.5%. The ‘mature’ CLEAs-BCL presented high stability in the ranges of temperature (30-70 ºС) and pH (pH = 5-10). Scanning electron microscopy (SEM) and circular dichroism (CD) studies showed that the morph secondary structure of ‘fresh’ and ‘mature’ CLEAs-BCL was variant to some extent, which may be responsible for the catalytic activity variance.

Sign in / Sign up

Export Citation Format

Share Document