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1.
Thin solid films of mixed Fe/Ti oxide composition (Fe/Ti molar ratios: 0.5∶1, 1∶1, 1.5∶1) have been made from Fe(NO3)3 alcoholic solution to which Ti(OiPr)4 was added. Films have been deposited by the dip-coating technique and heat-treated at 300°C and 500°C. Powders of Fe/Ti oxide
heat-treated at 300°C are amorphous, while powders annealed at 500°C for 40 hours transformed to mixed rutile, pseudobrookite
and hematite phases. The structure of the XRD amorphous films was identified with the help of near-normal reflection absorption
(6°) (IRRA) and near-grazing incidence angle (NGIA) spectroscopy. NGIA FT-IR spectra of films are characterised with a single
phonon mode appearing in the spectral range 600–950 cm−1 which shifts with increasing Ti concentration from 675 cm−1 (Fe2O3) to 904 cm−1 (TiO2) thus exhibiting one-mode behavior.
Electrochemical investigations made with the help of cyclic voltammetry (CV) and chronocoulometry (CPC) performed in 0.01M LiOH and in 1M LiClO4/propylene carbonate electrolytes revealed that films are able to uptake reversibly Li+ ions with a charge capacity (Q) per film thickness (d) in the range 0.1–0.26 mC/cm2nm and 0.06 mC/cm2nm, respectively. The temperature at which the films were prepared alters the rate of Li+ insertion which is faster for less compact films obtained at 300°C. In situ UV-VIS spectroelectrochemical measurements revealed
that Fe/Ti oxide films bleached in the UV spectral region (300 nm<λ<450 nm) and colored in the VIS spectral region (450 nm<λ<800
nm), thus exhibiting mixed anodic and cathodic electrochromism. 相似文献
2.
Bogdan Jurca Carmen Paraschiv Adelina Ianculescu Oana Carp 《Journal of Thermal Analysis and Calorimetry》2009,97(1):91-98
Activated carbons (AC), particularly those containing sulphur, are effective adsorbents for mercury (Hg) vapour at elevated
temperatures. Activated carbon-based technologies are expected to become a major part of the strategy for controlling mercury
emission from coal-fired power plants. Understanding the mechanism of mercury adsorption on sulphur impregnated activated
carbons (SIAC) is essential to optimizing activated carbons for better mercury removal efficiency and to developing technologies
for the handling of the spent AC.
In this work thermal analysis before and after mercury uptake was carried out for the SIAC prepared under various conditions
from oil-sand petroleum coke using a simultaneous differential thermal analyzer. Samples were heated at 20°C min−1 under nitrogen in the temperature range from ambient to 1000°C. The DSC curves suggest both endothermic and exothermic changes
during heating. The endothermic processes were attributed to evaporation of moisture and other volatile components. The exothermic
processes existed in a wide temperature range of 150–850°C likely due to the oxidation reactions between carbon and adsorbed
oxygen, oxygen-containing surface groups. The enthalpies of liquid mercury interaction with SIAC at different Hg/AC mass ratio
were also measured at 30, 40 and 50°C using a differential scanning calorimeter. The combination of thermal analysis and calorimetry
techniques enabled confirmation that the interaction of mercury with SIAC involves both physical and chemical processes. 相似文献
3.
H. Bayram M. Önal G. Üstünışık Y. Sarıkaya 《Journal of Thermal Analysis and Calorimetry》2007,89(1):169-174
An industrial raw material taken from Sivrihisar (Eskişehir, Turkey) region was heat-treated at different temperatures in
the range of 100–1000°C for 2 h. The volumetric percentage of the particles having a diameter below 2 μm after staying in
an aqueous suspension of the material was determined as 67% by the particle size distribution analysis. The mineralogical
composition of the material was obtained as mass% of 32% palygorskite, 10% metahalloysite, 35% magnesite, 20% dolomite and
3% interparticle water by using the acid treatment, X-ray diffraction and thermal analysis (TG, DTA) data.
The temperature ranges were determined for the endothermic dehydrations for the interparticle water as 25–140°C, for the zeolitic
water as 140–320°C, and for the bound water as 320–480°C, in the palygorskite. The temperature range for the endothermic dehydroxylation
and exothermic recrystalization of the palygorskite is 780–840°C. The temperature range for the endothermic dehydroxylation
of the metahalloysite and calcinations of magnesite are coincided at 480–600°C. Dolomite calcined in the temperature range
of 600–1000°C by two steps. The zig-zag changes in the specific surface area (S/m2 g−1) and specific micro and mesopore volume (V/cm3 g−1) as the temperature increases were discussed according to the dehydrations in the palygorkskite, dehydroxylation of palygorskite
and metahalloysite, and calcinations in magnesite and dolomite. 相似文献
4.
Tsai W. T. Chang C. Y. Lee S. L. Wang S. Y. 《Journal of Thermal Analysis and Calorimetry》2000,63(2):351-357
The thermochemical decomposition of agricultural by-product corn cob impregnated with ZnCl2, as a precursor material for producing the activated carbons, was investigated by thermogravimetric (TG) analysis at the
heating rate of 5 and 10°C min–1 under a controlled atmosphere of nitrogen (60 ml min–1). The appearance of a peak in the differential thermogravimetric plot (DTG) in the temperature range of 400–600°C is significantly
related to the extent of impregnation. The DTG curve of the sample impregnated with the optimal impregnation ratio of 175%
(i.e., the ratio of ZnCl2 mass of 87.5 g in the 200 cm3 of water to corn cobmass of 50 g), which yields an optimal BET surface area of the activated carbon and displays a DTG peak
at about 500°C. This may be partially due to the intense chemical activation and results in the formation of a porous structure
in the activated solid residue. This observation is also in close agreement with previous results at optimal pyrolysis temperatures
of 500°C and with similar experimental conditions. In order to support the results in the TG-DTG analysis, the development
of pore structure of the resulting activated carbons thus obtained by previous studies was also examined and explained using
the scanning electron microscopy (SEM).
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
5.
Thomaz Augusto Guisard Restivo Sonia Regina Homem Mello-Castanho 《Journal of Thermal Analysis and Calorimetry》2009,97(2):775-780
New 40 vol%[(Cu)–Ni]–YSZ cermet materials processed by mechanical alloying (MA) of the row powders are prepared. The powder
compacts are sintered in air, hydrogen and inert (argon) atmospheres at a dilatometer and tubular furnace up to 1,350 °C.
Sintering by activated surface concept (SAS) can anticipate and enhance the densification in such powders. Stepwise isothermal
dilatometry (SID) sintering kinetics study is performed allowing determining kinetic parameters for Ni–YSZ and Ni–Cu–YSZ pellets.
Two-steps sintering processes is indicated while Cu-bearing material features the smallest activation energy for sintering.
The allied MA–SAS method is a promising route to prepare SOFC fuel cell anode materials. 相似文献
6.
A. Wahby Z. Abdelouahab-Reddam R. El?Mail M. Stitou J. Silvestre-Albero A. Sepúlveda-Escribano F. Rodríguez-Reinoso 《Adsorption》2011,17(3):603-609
The textural characterization of a series of activated carbons prepared from olive stones, by carbonization at different temperatures
(400, 550, 700 and 850 °C) and thermal activation with CO2, has been investigated using N2 adsorption at −196 °C and CO2 adsorption at 0 °C. The effect of pre-oxidation of the carbonized precursor has also been studied, using temperature-programmed
decomposition (TPD), to evaluate the effect of oxygen content of the chars in the performance of the obtained activated carbons
for mercury removal. The adsorption of Hg(II) cations from aqueous solutions at room temperature by the prepared activated
carbons was studied. Experimental results show that all samples exhibit a large microporosity (pore diameter below 0.56 nm).
The amount of surface oxygen groups increased after pre-oxidation treatment, this enhancing the Hg(II) uptake (up to 72%).
It can be concluded that these groups make the support more hydrophilic, thus providing a more efficient adsorption of Hg(II).
The formation of a great amount of surface oxide groups such as carboxyl, phenol and lactone alters the surface charge properties
of the carbon, this enhancing the surface-Hg(II) interaction. 相似文献
7.
V. A. Dodonov A. A. Oleynik M. B. Molotovshchikova G. N. Lysenko O. N. Druzhkov 《Russian Chemical Bulletin》1993,42(10):1639-1642
Dimethyl- and diethylcadmium interact with both free hydroxyl and siloxane groups of the Aerosil surface to form ≡Si-O-Cd-C≡
and ≡Si-H fragments. At 200 °C these structures undergo β-elimination to form surface ≡Si-O-Cd-H groups. It has been established
that on heating to 600 °C, these groups decompose to afford metallic cadmium with the regeneration of the ≡Si-OH surface groups.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1717–1720, October, 1993. 相似文献
8.
1. Results of thermodynamic and kinetic investigations for the different crystalline calcium carbonate phases and their phase
transition data are reported and summarized (vaterite: V; aragonite: A; calcite: C). A→C: T
tr=455±10°C, Δtr
H=403±8 J mol–1 at T
tr, V→C: T
tr=320–460°C, depending on the way of preparation,Δtr
H=–3.2±0.1 kJ mol–1 at T
tr,Δtr
H=–3.4±0.9 kJ mol–1 at 40°C, S
V
Θ= 93.6±0.5 J (K mol)–1, A→C: E
A=370±10 kJ mol–1; XRD only, V→C: E
A=250±10 kJ mol–1; thermally activated, iso- and non-isothermal, XRD
2. Preliminary results on the preparation and investigation of inhibitor-free non-crystalline calcium carbonate (NCC) are
presented. NCC→C: T
tr=276±10°C,Δtr
H=–15.0±3 kJ mol–1 at T
tr, T
tr – transition temperature, Δtr
H – transition enthalpy, S
Θ – standard entropy, E
A – activation energy.
3. Biologically formed internal shell of Sepia officinalis seems to be composed of ca 96% aragonite and 4% non-crystalline calcium carbonate.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
9.
N. N. Chumachenko G. D. Bukatov S. A. Sergeev V. A. Zakharov 《Kinetics and Catalysis》2011,52(2):234-241
The oxidation state of titanium and the coordination state of Ti3+ ions in TiCl4/D1/MgCl2 (D1 is a phthalate) supported titanium-magnesium catalysts (TMCs) after the interaction with an AlEt3/D2 cocatalyst (D2 is propyltrimethoxysilane or dicyclopentyldimethoxysilane) were studied by chemical analysis and EPR spectroscopy. Different
oxidation state distributions of titanium ions were observed in the activated catalyst and mother liquor: Ti3+ and Ti2+ ions were predominant in the activated catalyst and mother liquor, respectively. The effects of interaction conditions (reaction
temperature and time and Al/Ti and D2/Ti molar ratios) of TMCs with the cocatalyst on the state of titanium in activated samples were studied. The interaction
of TMCs with the cocatalyst decreased the titanium content and caused the appearance of aluminum in the activated sample,
which was most clearly pronounced at a temperature of 25°C and occurred within the first 10 min of treatment. An increase
in the temperature to 70°C and an increase in the interaction time to 60 min only slightly affected the concentrations of
titanium and aluminum. The presence of D2 as a cocatalyst constituent facilitated the removal of titanium compounds and restricted the adsorption of aluminum compounds
on the catalyst surface. The main fraction of titanium consisted of Ti3+ ions (62–89%), and the rest was Ti4+ ions (22–35%) under mild interaction conditions (25°C; Si/Ti = 25) or Ti4+ (0–21%) and Ti2+ (9–21%) ions under more severe conditions (50 or 70°C; Si/Ti from 0 to 5). According to EPR-spectroscopic data, at D2/Ti from 1 to 5, Ti3+ ions mainly occurred as associates, whereas they occurred as isolated ions at D2/Ti = 25. The initial and activated catalysts were similar in activity in the reaction of propylene polymerization, and titanium
compounds, which were removed from the catalyst upon interaction with AlEt3/D2, were inactive in this process. 相似文献
10.
Alaa Eldin M. Abdel-Hady 《Transition Metal Chemistry》2008,33(7):873-878
A kinetic study of the oxidation of [Co(H2L)(H2O)2]2+ (H2L = N,N-bis (salicylaldehyde-1,2-diaminoethane) Schiff base) by periodate in aqueous solution was performed over pH (2.3–3.4) range,
(0.1–0.5) mol dm−3 ionic strength and temperatures 20–35 °C for a range of periodate and complex concentrations. The reaction rate showed a
first-order dependence on both reactants and increased with pH over the range studied. The effects of Cu(II) and Fe(II) on
the reaction rate were investigated over the (1.0–9.0) × 10−5 mol dm−3 range. The reaction was inhibited as the concentration of Cu(II) increased, and it was independent on Fe(II) concentrations
over the ranges studied. An inner-sphere mechanism is proposed for the oxidation pathways of both the protonated and deprotonated
CoII complex species. 相似文献
11.
Ingo G. M. Riccucci C. Bultrini G. Dirè S. Chiozzini G. 《Journal of Thermal Analysis and Calorimetry》2001,66(1):37-46
Amorphous SiO2, TiO2 and xSiO2–(1–x)TiO2 ceramic materials with selected values of x 0.5, 0.7 and 0.9, have been prepared via sol-gel process using silicon tetraethoxysilane (TEOS) and titanium tetraisopropoxide
Ti(OPri)4. By means of the combined use of differential thermal analysis (DTA),thermogravimetry (TG), X-ray diffraction (XRD), scanning
electron microscopy (SEM),X-ray photoelectron spectroscopy (XPS) and X-ray induced Auger electron spectroscopy(XAES), the
surface microchemical structure and morphology of the sol-gel materials have been studied as a function of thermal treatments
carried out in air up to 1200°C. In the range of temperature from 50 to 450°C, DTA-TG results evidence a remarkable mass loss
due to the evaporation of organic solvents entrapped in the sol-gel materials and of the remnant organic components of the
precursor metal alkoxides. In the range of temperature from 400 to about 1000°C, by means of the combined use of DTA, XRD,
XPS and XAES techniques as a function of temperature and of chemical composition, it is possible to evidence the formation
of crystalline phases such as quartz, anatase and rutile. Furthermore, line shape analysis of O1s XPS peak allows to distinguish
between single O–Ti and O–Si bonds and also to disclose the presence of cross linking Si–O–Ti bonds, that act as bridges between
SiO2and TiO2 moieties. As a function of temperature, Si–O–Ti bonds are broken and the formation of new Ti–O and Si–O bonds as in TiO2 and SiO2takes place as well as a silica segregation phenomenon.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
12.
T. N. Rostovshchikova M. S. Korobov D. A. Pankratov G. Yu. Yurkov S. P. Gubin 《Russian Chemical Bulletin》2005,54(6):1425-1432
Nanosized iron oxides stabilized on the surface of ultradispersed poly(tetrafluoroethylene) (UPTFE) granules were synthesized
by the thermal destruction of iron formate in boiling bed of UPTFE on the surface of heated mineral oil. The particle size
of nanoparticles (∼6 nm) containing 5, 10, and 16 wt.% Fe depends weakly on the temperature of synthesis and iron to polymer
ratio. The metal state is determined by the synthesis conditions. The nanoparticles synthesized at 280 °C consist mainly of
the Fe3O4 and Fe2O3 phases. The samples obtained at 320 °C also contain iron(II) oxide. The catalytic properties of the obtained samples were tested in dichlorobutene isomerization. Unlike isomerization
on the iron oxide nanoparticles supported on silica gel, reaction over the UPTFE supports proceeds without an induction period.
The sample with 10 wt.% Fe containing magnetically ordered γ-Fe2O3 nanoparticles possesses the highest catalytic activity. Fast electron exchange between the iron ions in different oxidation
states and high defectiveness of the nanoparticles contribute, most likely, to the catalytic activity.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1383–1390, June, 2005. 相似文献
13.
Tanmay Chattopadhyay Manami Ghosh Arpita Banerjee Kazi Sabnam Banu Debasis Das Munirathinam Nethaji 《Transition Metal Chemistry》2007,32(4):531-535
Linkage isomers trans-bis(N-propyl-1,2-diaminoethane)dinitronickel(II) (brown, 1), trans-bis(N-isopropyl-1,2-diaminoethane)dinitritonickel(II) (blue-violet, 2a) and trans-bis(N-isopropyl-1,2-diaminoethane)dinitronickel(II) (brown, 2b) have been synthesized from solution and X-ray single crystal structure analysis of complex (1) has been performed. Simultaneous TG-DTA analyses reveal that complex (1) exhibits two successive phase transitions before to undergo decomposition (initial temperature of decomposition, Ti = 215
°C). The first one is reversible (82–98 °C; ΔH = 1.75 kJ mol−1 for heating and 93–77 °C; ΔH = −1.65 kJ mol−1 for cooling) and the second one is irreversible endothermic (135–150 °C kJ mol−1; ΔH = 1.80 kJ mol−1) phase transition. No visual color changes are observed in any of the two transitions. The causes related to the first phase
transition remain unexplored. However, on the basis of IR spectral studies the second phase transition is supposed to be due
to conformational changes of the diamine chelate rings. On the other hand, complexes (2a) and (2b) undergo decomposition without showing any phase transition [Ti = 185 and 195 °C for (2a) and (2b), respectively]. 相似文献
14.
M. Getsova D. Todorovsky V. Enchev I. Wawer 《Monatshefte für Chemie / Chemical Monthly》2007,4(4):389-401
Cerium(III/IV) and Ce(IV)–Ti(IV) citric complexes were synthesized in ethylene glycol medium under conditions similar to those
of the polymerized complex method (PCM). Solution phase 1H, 13C NMR, solid state 13C CP MAS NMR and IR spectroscopy, and X-ray powder diffractometry were used to characterize the composition and structure
of the synthesized products. Thermal decomposition of the isolated complexes was studied and a scheme of the processes taking
place is proposed. Complexes of Ce(III) can be prepared at low temperature (40°C), only. In the presence of Ti(IV) ions, the
oxidation takes place even at this temperature. A mixed-metal nature of the Ce(IV)–Ti(IV) complexes is established. The comparison
between their composition and the one of analogous lanthanide(III)–Ti(IV) citrates contributes to the elucidation of the complexation
process mechanism in the case of the PCM application. The increased charge of the complexation agent in the Ce4+–Ti4+ complex (in comparison with Ln
3+–Ti4+ citrates) is “compensated” by the increase of the relative number of the ligands with deprotonated OH group. 相似文献
15.
M. Getsova D. Todorovsky V. Enchev I. Wawer 《Monatshefte für Chemie / Chemical Monthly》2007,138(5):389-401
Summary. Cerium(III/IV) and Ce(IV)–Ti(IV) citric complexes were synthesized in ethylene glycol medium under conditions similar to those
of the polymerized complex method (PCM). Solution phase 1H, 13C NMR, solid state 13C CP MAS NMR and IR spectroscopy, and X-ray powder diffractometry were used to characterize the composition and structure
of the synthesized products. Thermal decomposition of the isolated complexes was studied and a scheme of the processes taking
place is proposed. Complexes of Ce(III) can be prepared at low temperature (40°C), only. In the presence of Ti(IV) ions, the
oxidation takes place even at this temperature. A mixed-metal nature of the Ce(IV)–Ti(IV) complexes is established. The comparison
between their composition and the one of analogous lanthanide(III)–Ti(IV) citrates contributes to the elucidation of the complexation
process mechanism in the case of the PCM application. The increased charge of the complexation agent in the Ce4+–Ti4+ complex (in comparison with Ln
3+–Ti4+ citrates) is “compensated” by the increase of the relative number of the ligands with deprotonated OH group. 相似文献
16.
I. Oja
Açik J. Madarász M. Krunks K. Tõnsuaadu D. Janke G. Pokol L. Niinistö 《Journal of Thermal Analysis and Calorimetry》2007,88(2):557-563
Thermal decomposition of precursor xerogels for TiO2,
obtained by gelling of acetylacetonate-modified titanium(IV) tetraisopropoxide
(prepared at Ti-alkoxide:acetylacetone molar ratios of 1:1 (Ti-1) and 1:2
(Ti-2)) in boiling 2-methoxyethanol, was monitored by simultaneous TG/DTA/EGA-MS
and EGA-FTIR measurements. Thermal degradation processes of Ti-1 and Ti-2
in the temperature range of 30–700°C consist of six mass loss steps,
the total mass loss being 46.3% and 54.4%, respectively. EGA by FTIR and MS
revealed release of H2O below 120°C; followed by
evolution of acetone and acetic acid between approximately 100 and 320°C,
and that of CO2 up to 560°C. Acetylacetone is evolved
to a significant extent from sample Ti-2 at 120–200°C. 相似文献
17.
A series of silicon containing poly(ester imide)s [PEIs] were synthesized using novel vinyl silane diester anhydride (VSEA)
and various aromatic and aliphatic dimines by two-step process includes ring-opening polyaddition reaction to form poly(amic
acid) and thermal cyclo-dehydration process to obtain poly(ester imide)s. VSEA was synthesized by using dichloro methylvinylsilane
and trimellitic anhydride in the presence of K2CO3 by nucleophilic substitution reaction. The PEIs were characterized by FTIR spectroscopy. The thermal properties of PEIs were
investigated by using differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) methods. The prepared PEIs
showed glass transition temperatures in the range of 320–350°C and their 5% mass loss was recorded in the temperature range
of 500–520°C in nitrogen atmosphere. These had char yield in the range of 45–55% at 800°C. 相似文献
18.
A TPD-MS study of the adsorption of ethanol/cyclohexane mixture on activated carbons 总被引:1,自引:0,他引:1
Camelia Matei Ghimbeu Roger Gadiou Joseph Dentzer Lo?c Vidal Cathie Vix-Guterl 《Adsorption》2011,17(1):227-233
The adsorption of ethanol/cyclohexane binary mixtures on different types of activated carbons was studied in this work by
temperature programmed desorption coupled with mass spectroscopy (TPD-MS). The texture, morphology and surface chemistry of
the carbons were evaluated by N2 adsorption, scanning electron microscopy (SEM) and TPD-MS techniques. The ethanol and cyclohexane TPD-MS desorption profiles
showed that specific interactions between the carbon material and the adsorbate are involved during the adsorption. Most of
the activated carbons adsorb strongly ethanol on the surface, leading to desorption temperatures above 100 °C. Only one carbon
exhibits an affinity for cyclohexane. These observations were correlated to the different surface chemistry of the materials. 相似文献
19.
Bharti U. N. Verma Kingsuk Mukhopadhyay 《Journal of Thermal Analysis and Calorimetry》2011,104(3):1071-1075
The ligand [2-(1,2,3,4-thiatriazole-5-yliminomethyl)-phenol] (L) is a schiff base derived from condensation reaction of 1,2,3,4-thiatriazole-5-ylamine
and Salicylaldehyde. Synthesis of the ligand (L) and the complex [Cu(II)(L)2]·2H2O have been studied in our previous work (Bharti et al., Asian J Chem 23(2):773–776, 2011). Thermal decomposition behavior
of synthesized Cu(II) complex has been investigated by thermo gravimetric (TG) analysis at heating rate of 10 °C min−1 under nitrogen atmosphere. The mechanism of decomposition of Cu(II) complex has been established from TG data. Kinetic parameters
such as order of reaction (n), activation energy (E
a), frequency factor (Z) and entropy of activation (∆S
≠) were calculated by using Freeman and Carroll (J Phys Chem 62:394–397, 1958) as well as Doyle’s methods as modified by Zsako
(J Phys Chem 72(7):2406–2411, 1968). 相似文献
20.
Sari MM 《Applied biochemistry and biotechnology》2011,163(8):1020-1037
Cupric ion-chelated poly(hydroxyethyl methacrylate-n-vinyl imidazole) (poly(HEMA-VIM)) microspheres prepared by suspension polymerization were investigated as a specific adsorbent
for immobilization of yeast invertase in a batch system. They were characterized by scanning electron microscopy, surface
area, and pore size measurements. They have spherical shape and porous structure. The specific surface area of the p(HEMA-VIM)
spheres was found to be 81.2 m2/g with a size range of 70–120 μm in diameter, and the swelling ratio was 86.9%. Then, Cu(II) ion chelated on the microspheres
(546 μmol Cu(II)/g), and they were used in the invertase adsorption. Maximum invertase adsorption was 51.2 mg/g at pH 4.5.
Cu(II) chelation increases the tendency from Freundlich-type to Langmuir-type adsorption model. The optimum activity for both
free and adsorbed invertase was observed at pH 4.5. The optimum temperature for the poly(HEMA-VIM)/Cu(II)-invertase system
was found to be at 55 °C, 10 °C higher than that of the free enzyme at 45 °C. V
max values were determined as 342 and 304 U/mg enzyme, for free and adsorbed invertase, respectively. K
m values were found to be same for free and adsorbed invertase (20 mM). Thermal and pH stability and reusability of invertase
increased with immobilization. 相似文献