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中文
Table of Content
24 September 2001, Volume 22 Issue 9
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Articles
Hydrothermal Synthesis and Ionic Conduction Properties of Ce
1-x
M'
x
Ca
0.2
O
1.8-0.4x
(M=Y, La and Gd)
ZHAO Hui, ZHU Xiang-Rong, LIU Shuang-Long, HAN Dong-Lin, XU Wei, FENG Shou-Hua
2001, 22(9): 1441-1445.
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Aseries of lanthanide co doped ceria solid solution, Ce
1-x
M'
x
Ca
0.2
O
1.8-0.4 x
(M=Y, La and Gd) has been prepared by mild hydrothermal method at 240 ℃ for less than 24h. The doping effect of lanthanide on the conduction properties was investigated. It is found that the conductivity increased from Y, Gd to La, whereas the activation energy changed in a reverse trend. It is also found that the mean particle size decreases from Y, Gd to La, they are 32 nm, 20 nm and 15 nm, respectively. All these results can be contributed to the size similarity of Y
3+
and Ce
4+
.
Synthesis, Anticancer Activity and Mechanism of Water-soluble Porphyrin and Metalloporphyins
LIU Jie, XU Dong-Hui, MEI Wen-Jie, PU Han-Lin, HUANG Jin-Wang, JI Liang-Nian
2001, 22(9): 1446-1449.
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A water-soluble porphyrin tetrakis[4-(trimethylammoniumly)phenyl]porpyrin (TAPP) and its metalloporphyrin derivatives MTAPP with M=Zn(Ê),Cu(Ê),Fe(Ë),Co(Ë),Ni(Ê),Mn(Ë), containing various functional groups within the porphyrin have been synthesized and characterized by elemental analysis, and UV-Vis spectra. Binding of TAPP and Zn-TAPP with calf thymus DNAwas investigated by absorption spectra, fluorescence spectra and viscosity measurements. Addition of CT DNAresulted in obvious hypochromism and bathochromic of 12 nm in absorption spectra, and an enhancement in fluorescence spectra were also observed. The anticancer activities of these complexes were also tested by MTTon two mice tumor cells of Ac and Hept, the results indicated that Co(Ë)-TAPPshowed a high inhibitory action and high anticancer activity in cell.
Synthesis and Characterization of a Novel Hybrid Single Crystal [Ga
3
(PO
4
)
3
F
2
]H
3
O·(H
3
NCH
2
CH
2
)
2
NH
2
YAO You-Wei, ZHAO Yong-Nan, YUE Shan-Tang, XU Heng-Lian, LIANG Hong-Bin, ZHAO Da-Qing
2001, 22(9): 1450-1452.
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Anovel three dimensional fluorinated gallium-phosphate has been hydrothermally synthesized by using diethylenetriamine as an organic structure directing agent. X-ray single crystal structure analysis indicates this compound crystallizes in the orthorhombic space group Pbca, a=1.6056(7) nm, b=10114 (4) nm, c=1.8546(5) nm, V=3.0116(19) nm
3
, Z=4. The three dimensional framework based on linkage of corner sharing polyhedron PO
4
, GaO
4
Fand GaO
4
F 2 delimit ten ring channels along b axis in which the triply protonated amines are located serving as charge compensating guests and supporters.
Synthesis and Photocatalytic Behavior of Layered Double Hydroxide Pillared by Paratungstate A Ion, Mg
12
Al
6
(OH)
36
(W
7
O
24
)·4H
2
O
GUO Yi-Hang, LI Dan-Feng, HU Chang-Wen, WANG Yong-Hui, WANG En-Bo
2001, 22(9): 1453-1455.
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Layered double hydroxide pillared by Paratungstate Aion, Mg
12
Al
6
(OH)
36
(W
7
O
24
)·4H
2
O, was prepared via anion exchange reaction of the synthetic precursor, Mg
4
Al
2
(OH)
12
TA·x H
2
O(TA
2-
=terephthalate), and W
7
O
24
6-
ion. Trace aqueous organochlorine pesticide, hexachlorocyclohexane, was totally degraded and mineralized into CO
2
and HCl by irradiating a suspension of Mg
12
Al
6
(OH)
36
(W
7
O
24
)·4H
2
Oand HCHin the near UVarea. The model and pathway for the photocatalytic degradation of HCHon the Mg
12
Al
6
(OH)
36
(W
7
O
24
)·4H
2
Owere proposed, indicating that the interlayer space is the reaction field, and that photogeneration of OH ·radicals are responsible for degradation pathway.
A New Technique for the Synthesis of Carbon Nanotubes From Coal
TIAN Ya-Jun, XIE Ke-Chang, FAN You-San
2001, 22(9): 1456-1458.
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Anew technique for the synthesis of carbon nanotubes from coal is introduced in this paper. In this process, coal is selected as the raw material to injected into plasma jet directly, nanotubes are formed on the reactor wall. The metal elements contained in parent coal such as Cu, Al act as the catalyst. This technique is different from the traditional arc discharge process and has the advantages of easy and steady operation and low cost of raw material, so it is an attractive process.
Sponge-like Architectured Macroporous Oxides Templating by Egg White
FAN Jie, YU Cheng-Zhong, TU Bo, ZHAO Dong-Yuan
2001, 22(9): 1459-1461.
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In this paper, a novel protein templating approach to synthesize macroporous materials has been demonstrated. Sponge like architectured macroporous oxides(silica, titania) have been firstly synthesized by using low cost commercial egg white protein as the template. The pore size of the three dimensional macroporous materials can be tuned from 50 to 400 nm by adding different surfactant. The morphology and the channel of the macroporous materials can also be controlled by the surfactant. The formation of macroporous material is resulted from the phase separation between the protein and inorganic sol.
A Preliminary Study of Purification and Bioactivity of a 12600 Shark Cartilage Angiogenesis Inhibitor
ZENG Feng, XIE Tuan-Xia, YANG Wei-Xing, ZHANG Zhan-Xia, YU Jian-Xiu, PANG Yi
2001, 22(9): 1462-1465.
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The purification method and bioactivity of shark cartilage angiogenesis inhibitor a(SCAIa) from Guangdong Yangjiang were investigated. The 1.0 mol/Lguanidine and 002 mol/L MES(at 28 ℃ ) extracts of shark cartilage was centrifuged at 6000 r/min for 30 min and the pellet was discarded, and the supernatant was recentrifuged at 12000 r/min for 30 min, then ultrafiltrated and fractionally precipitated with 25%-90% acetone. The precipitate was applied to a Sephadex G 75 gel column and eluted after the predominant peak of A
280nm
absorbing material with 0.05 mol/L Tris HCl buffer(containing 0.02mol/L NaCl and 0.02% NaN
3
). The material Bwere composed of three single peptides with molecular mass of 18000, 15000 and 12600, then were purified using reverse phase high performance liquid chromatography, the eluate was collected, dried and observed by chichen chorioallantoic membrane. The pure inhibitor was homogeneous as a single band on a silver stained 125% sodium dodecyl sulfate polyacrylamide gel. SCAIa had a molecular weight of 12600. It specifically inhibited the chorioallantoic membrane of chick embryos.
Studies on Quantitative Structure-property Relationship of Lanthanide Metal Ions Using an Artificial Neural Network
YANG Xing-Hua, YIN Chun-Sheng, PAN Zhong-Xiao
2001, 22(9): 1466-1471.
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Systematical studies were made on the influencing factors concerned to the complexation, hydration, etc of lanthanide metal ions. Aset of parameters such as ionic radii, electronegativity, base state Lvalues, and periodic factors, defined in this work, were used to nonlinearly correlate the stability constants lg Kof EDTA, NTA and HTTAcomplexes, hydration energy Δ H, hydrolysis constants p K
1
and pK
m
of hydroxides of the lanthanide metal ions with the functional link net(FLN). The obtained results are satisfactory, and better than that obtained by using linearly statistic method. Some of the absent constants values were predicted by FLN.
Cation Recognition of Luminescent Ionophore-dansyl-monoaza-18-crown-6
LI Long-Di, WU Ying-Guang, TONG Ai-Jun, LONG Wen Qing
2001, 22(9): 1472-1476.
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Using the title ionophore DNS MAC(O
5
) as the host, its cation recognition properties for Li
+
, Na
+
, K
+
, Mg
2+
, Ba
2+
and Pb
2+
in acetonitrile and in aqueous solution were studied by fluorescence and NP RTPmethod, respectively. The corresponding stability constants and the recognition sensitive factors for the host guest complexes were determined. The results proved that the charge of guest cation and the spatial matching requirement between azacrown ring and the cation are the two most important factors on the recognition process. DNS MAC(O
5
) undergoes obviously a spectral change upon binding with cation. These changes are mainly controlled by the charge density of the cation. When the azacrown ether moiety of the ionophore was coordinated with a cation, not only the dipole moment of the lumino ionophore was increased, but also it was more favorable for the photoinduced intramolecular charge transfer, so the stability of exited state was increased and the fluorescence spectrum was red shifted. At the same time, the relative fluorescence quantum of DNS MAC(O
5
) in water and acetonitrile was determined by the comparative method in this paper.
Self-enrichment Effect of Neutral Solute in CEC
ZHANG Wei-Bing, ZHU Jun, ZHANG Yu-Kui
2001, 22(9): 1477-1480.
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During the injection of neutral solute in CEC, the partition equilibrium of solute between mobile phase and stationary phase will lead to an inhomogeneous distribution along column axes and bring on a self enrichment effect. Based on the relaxation theory, the transfer process of solute in column is delt with by no dimension method. The transfer equation forms an increasing series by degree. This equation is also solved with production function, and the second central moment of the profile is derived. Compared to the common injecting process and self enrichment, the expression which describes the effect of injecting time and retention value on enrichment is theoretically held and experimentally investigated with two drugs: mephenytoin and benzoin. The results show that the longer the injecting time and the larger the capacity factor of solute, the stronger the self enrichment effect. Under the conditions of constant column efficiency, the self enrichment effect can increase more than 10 fold detection sensitivity to the experimental solute.
Determination of Volatile Components of Ping-wei Powder(Ⅱ) --Analysis of the Volatile Oil in Cortex Magnoliae Officinalis with GC/MS
GONG Fan, LIANG Yi-Zeng, SONG You-Qun, PENG Yuan-Gui, Leung-Alexander-Kaiman, Chau-Footim
2001, 22(9): 1481-1485.
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This paper aims at detecting chemical components of the volatile oil in Cortex Magnoliae Officinalis with GC/MS. With the help of heuristic evolving latent projections(HELP) resolution and overall volume integration method upon two way data, 98 components are separated and 44 of them qualitatively and quantitatively analyzed representing about 58.74% of the total content.
Studies on the Electron Transfer for Reaction Center Isolated from Rhodobacter Sphaeroides in Self-assembly Composite Film
ZHAO Jie-Quan, ZOU Yong-Long, LIU Bao-Hong-PENG Xue-Song, XU Chun-He, KONG Ji-Lie, CUI Da-Fu
2001, 22(9): 1486-1491.
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The composite ordered protein film was assemblied on the surface of a gold electrode by self-assembly mono layer approach using meso 2,3 dimercaptosuccinic acid(DMSA), poly dimethyldiallylammonium chloride(PDDA) and reaction center membrane protein purified from purple bacteria(Rhodobacter sphaeroides). Square wave voltammetry(SWV) was employed to study the electrochemical behavior of the protein composite film. The reversible or quasi reversible electron transfer for redox couples therein was successfully detected. The reduction potential for each redox couple and the electrochemically driven effect was also discussed. The typical SWV-results were non linearly fitted to get the kinetic parameters for the composite protein film.
Studies on the Synthesis and Characters of Ferrocene Labeled DNA Probe
XU Chun, CAI Hong, HE Pin-Gang, FANG Yu-Zhi
2001, 22(9): 1492-1495.
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The preparation and characters of a ferrocene labeled DNAprobe was studied. Ferrocene was labeled onto a denatured calf thymus DNAby EDC. The electrochemical character, UVspectrum and IRspectrum of the ferrocene labeled probe were discussed. It was suggested that the ferrocene be labeled on the phosphoric group of calf thymus DNA. The probe synthesis was simple, quick and of efficiency. It made bases for the application of electrochemical DNAprobe to DNAdetection, damage and protection.
Synthesis, Characterization and Crystal Structure of Some Organotinferrocene and Organoarsinoferrocene Derivatives
DU Hong-Guang, WANG Shu-Ming, SHEN Li-Yang, SHI Shu-Jian
2001, 22(9): 1496-1500.
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The monolithio compound of N,N-dimethylaminomethylferrocene reacted with tribenzyltin chloride and dibenzyldichlorotin to form 2-(tribenzyltin)dimethylaminomethylferrocene(Ⅰ) and dibenzyl bis(2-dimethylaminomethylferrocenyl)tin(Ⅱ) respectively. While the monolithio compound of 2-(diphenylarsino)dimethylaminomethylferrocene reacted with diphenylchloroarsine to give 2,5-di(diphenyl-arsino)dimethy laminomethyl ferrocene(Ⅲ). The reaction of the dilithio compound of 2-(diphenylarsino)dimethylaminomethylferrocene with 2 mol diphenylchloroarsine gave 2,5,1'-tri(diphenylarsino)dimethyl-aminomethylferrocene(Ⅳ). The structures of the products were characterized by elemental analysis and
1
H NMRspectra. The structure of compound Ⅳ was established by X-ray crystal structure determination. The crystal of Ⅳ is triclinic, space group P1, with unit cell parameters: a=1.0548(2) nm, b=1.3622(3) nm, c=1.5846(3) nm, α=95.87(3)°, β=96.54(3)°, γ=107.67(3)°, Z=2.
Reaction of Divalent Samarium Complexes with Phenyl Isocyanate Synthesis, Molecular Structure and Catalytic Activity of [(CH
3
C
5
H
4
)
2
(THF)Sm]
2
[μ-η
4
-(PhN)OCCO(NPh)]·2THF
YUAN Fu-Gen, SHEN Qi, SUN Jie
2001, 22(9): 1501-1505.
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This article describes the reaction of divalent complexes (CH
3
C
5
H
4
)
2
Sm(THF) and SmI
2
(THF)
x
with phenyl isocyanate.(CH
3
C
5
H
4
)
2
Sm(THF) reacts with phenyl isocyanate to give the product of [(CH
3
C
5
H
4
)
2
(THF)Sm]
2
[μη
4
(PhN)OCCO(NPh)]·2THF(1), while SmI
2
(THF)
x
was oxidated to be [SmI
2
(THF)
5
][SmI
4
(THF)
2
] in PhNCOsolution. (CH
3
C
5
H
4
)
2
Sm(THF) and complex 1 display a catalytic activity for the oligomerization of phenyl isocyanate. The reaction of(CH
3
C
5
H
4
)
2
Sm(THF) with PhNCO to form complex 1 can be thought as the initiation reaction and complex 1 may be considered to be the real active species for the PhNCOoligomerization with the catalyst of(CH
3
C
5
H
4
)
2
Sm(THF). The structure of complex 1 was determined by X-ray diffraction analysis and confirmed to be a bimetallic complex with a dianionic oxamide ligand.
AM1 Study on the Mechanism of Catalytic Hydrogenation of 3-Anilinomethy lidene-6-alkyl-5,6-2H-dihydropyran-2,4-diones
FANG Ya-Yin, SHEN Rong-Xin, SUN Hong-Wei, YUAN Man-Xue, LIU Jie-LI Zheng-Ming, LAI Cheng-Ming
2001, 22(9): 1506-1510.
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3-(p-Methyl) anilinomethylidene 6-methyl 5,6-Hdihydropyran-2,4-dione was selected as model reactant to study the mechanism of catalytic hydrogenation of 3-anilinomethylidene 6-alkyl-5,6-2Hdihydropyran-2,4-diones by means of the AM1 and UHF/6-311Gmethods. The molecular informations such as heats of formation, net charges, bond orders, the values of frontier orbital energies, composition, their proportion and bonding contribution were acquired and analyzed. Thus the possible reactive sites were put forward and the reaction mechanism was postulated via two steps. The postulated intermediates and products of the two steps were also computed by AM1 method. Their heats of formation and energies of HOMO/LOMO/LUMOindicate that the mechanism of catalytic hydrogenation of 3-anilinomethylidene 6-alkyl-5,6-2Hdihydropyran-2,4-diones is not only a hydrogenolytic addition on CCbond but also a hydrogenolytic cleavage of the C-Nbond of anilinomethylidene.
Chiral Total Synthesis of (+)-Montbretyl12-Methyl Ether and (-)-Montbretyl12-Methyl Ether
LI An-Pai, PENG Xiao-Shui, WU Xiao-Ming, WU Tong-Xing, PAN Xin-Fu
2001, 22(9): 1511-1514.
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By using (S)-(-)-α-cyclocitral(9a) and(R)-(+)-α-cyclocitral(9b)-obtained by chemical resolution as the Aring synthon, and triphenyl phosphonium chloride(18)-obtained from p bromoanisole via eight steps as the Cring synthon, the sole trans key intermediate 3 was obtained after the condensation and intracyclization reactions. The structure modification, (+)-montbretyl-12-methyl ether(1a)-and-(-)-montbretyl-12 methyl ether(1b) were obtained enantioselectively. The cyclization reaction of BF3·Et
2
Ois the key step.
A New Diterpene Lactone from the Soft Coral Sarcophyton molle Tix. Dur.
SU Jing-Yu, YAN Su-Jun, ZENG Long-Mei
2001, 22(9): 1515-1517.
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Two diterpene lactones, sarcophinone(1) and iso sarcophinone(2), which are biogenetically related to the sarcophine, were isolated from the soft coral Sarcophyton molle Tix. Dur. iso Sarcophinone 2 is a new compound. Its structure was determined to be C-1 epimer of sarcophinone by spectroscopic methods. Bioassay showed that both sarcophinone(1) and iso sarcophinone(2) had potent cytotoxicity toward Ehrlich and S180 tumor cell lines.
Dibenzocyclooctadiene Lignans from Schisandra Propinqua
CHEN Ye-Gao, QIN Guo-Wei, XIE Yu-Yuan
2001, 22(9): 1518-1520.
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Eight dibenzocyclooctadiene lignans were isolated from the stems of Schisandra propinqua(Wall.)Hook. f. et Thoms. Their structures were elucidated as acetylgomisin R(1), angeloylgomisin R(2), gomisins A(3), B(4), N(5) and O(6), 6 Obenzoylgomosin O(7) and schisantherin A(8) by spectral studies. Among them, compound 1 was a new one, compound 2 was discovered in the genus Schisandra for the first time and the others were originally isolated from Schisandra propinqua.
Theoretical Study on the Weak-interaction of Thiophene-Na Charge Transfer Complex with Density Functional Theory
ZHANG Chong, BU Yu-Xiang
2001, 22(9): 1521-1525.
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Geometric parameters of three Na thiophene complexes(A, B, C) and the ground state bonding energy Δ Ehave been determined at the B3LYP/6-311+G
*
level in this paper. The results have indicated that there are two energy minimum points on the potential energy surface which correspond to two stable structures(Aand C) and geometry Bdoes not exist. Of the two structures, the geometry Acorresponds to the ground state in which R (Na-S)=0.407 nm and ∠CSC=91°, structure Cwith R (Na-S) of 0.825 nm and ∠CSCof 91° is energetically higher than structure Aby 78.0 kJ/mol. For structure A, 3s orbital of Na atom directly interacts with Π
5
6
bonding of the thiophene molecule, resulting in a new weak interaction organometallic complex with Cs symmetry. For the structure C, 3 s orbital of Na mainly interacts with the two Catoms apart from Satom in thiophene, forming a new Π
6
7
bonding derived from original Π
5
6
bonding of thiophene, but the structure Chas C
2v
symmetry. There is also a slight geometry deformation of thiophene molecule plane for structure Ain which the Sis slightly apart from cyclic Cplane. The bonding energies Δ Eaccurately calculated using by MP2, MP3, MP4 and B3LYPmethods with 6-311+G
*
and 6-311++G
*
*
basis sets for the ground state structure Afall within 8.3-10.9 kJ/mol.
Catalytic Behavior of Lipase in W/O Microemulsion and Immobilized Lipase in Gelatin Microemulsion-Based Organogels
ZHOU Guo-Wei, LI Gan-Zuo, HUANG Xi-Rong, XU Jian, HE Hong-Juan, LI Chuan-Guang
2001, 22(9): 1526-1529.
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The kinetics of the esterification of lauric acid and 1 pentanol catalyzed by Calytical (CL) lipase, was studied in water/bis (2-ethylhexyl)sulfosuccinate sodium(AOT)/isooctane microemulsions. The kinetics studies showed that the reaction followed a Ping Pong Bi-Bi mechanism. The values of all apparent kinetic parameters were determined. The apparent kinetic parameters of the reaction were found to be k
m
(lauric acid)=013518 mol/L, k
m
(1 pentanol)=022423 mol/Land v
max
=13873×10
-5
mol/(L·min·mg). Lipase has also been immobilized in gelatin containing AOT-microemulsion based organogels(MBGs). These lipase containing MBGs prove to be a novel solid-phase catalysts for the use in apolar organic solvents and have a good physical stability. These lipase containing MBGs retained its higher activity after 10 runs esterification reactions.
Theoretical Study on the Gas Phase Reaction: B
2
H
3
-
+CS
2
B
2
H
3
S
-
+CS
QU Zheng-Wang, LI Ze-Sheng, DING Yi-Hong, SUN Chia-Chong
2001, 22(9): 1530-1534.
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The mechanism for the gas phase ion molecule reaction B
2
H -
3+
CS
2
B
2
H
3
S
-
+CShas been investigated theoretically by using the B3LYP/6311++G( d,p ) and the high level electron correlation CCSD(T)/6311++G( d,p ) single point levels. It is shown that the B
2
H
3
-
anion may attack the carbon atom of CS
2
to form a three membered ring intermediate followed by a Hshift and subsequently a CSextrusion steps to reach the final dissociation product H
3
BBS
-
+CS. The reaction is largely exothermic and no activation energy is needed for this three membered ring mechanism. On the other hand, an activation barrier is found for the sulfur atom abstraction reaction initiated by the sulfur attack of B
2
H
3
-
towards CS
2.
The calculated results presented in this paper may be helpful for understanding the chemical behavior of electron deficient boron hydride anions such as B
2
H
3
-
, B
3
H
6
-
and B
4
H
7
-
, etc..
Formation of Active Phase of the Catalyst for the Reaction of Methane Aromatization
MA Ding, SU Ling-Ling, SHU Yu-Ying, XU Yi-De, BAO Xin-He
2001, 22(9): 1535-1538.
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The behavior of different species during the temperature programmed surface reaction (TPSR) of methane over various catalysts is traced by an on line mass spectrometer. It is demonstrated that the transformation of MoO
3
to molybdenum carbide hinders the activation of methane as well as the succeeding aromatization in the TPSR. If this transformation process is done before the reaction, the temperature needed for methane activation and benzene formation will be greatly lowered(760 Kand 847 K, respectively). It is strongly suggested that molybdenum carbide is one of the active center of this catalytic process.
Studies on the Stability about C
36
H
2
Isomers and Selection Rules for Choosing Positions in Additive Reaction
YANG Zuo-Yin, WANG Gui-Chang, SHANG Zhen-Feng, PAN Yin-Ming, WU Ben-Xiang, ZHAO Xue-Zhuang
2001, 22(9): 1539-1542.
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By using AM1 and PM3 methods, the nonrestrictive symmetrical C
36
H
2
isomers based on symmetrical C
36
( C
6v
, C
6h
and D
2d
) fullerenes have been exhaustively searched. According to the relationship between isomer stability and adding positions, we have induced three sorts of laws about H
2
choosing different places in the additive reactions.The results of the POAVanalysis show that the reactivity is forced by the intensive strains in the C
36
cages. On the other hand, in order to form stable compounds, the rules which guide H
2
chooses different carbon atoms are mainly determined by the conjugated effects in C
36
H
2
system, rather than strains released in C
36
cages.
Thermodynamic Research on the Coating Process of Silica Nano Film on Titanate Particles Surface
CUI Ai-Li, WANG Ting-Jie, JIN Yong, SUN Mu
2001, 22(9): 1543-1545.
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The critical nucleation radius is 2.8 nm obtained from calculation with thermodynamic method. If the nucleus caused by fluctuation is less than 2.8 nm, the nucleus will not grow up. Though the thermodynamic analysis is semi ideal, it is effective. We find a solution system in which the nucleation does not take place uniformly, but does on the surfaces of different solid phases. It gives a feasibility theoretically for titanate being coated uniformly with silica nanofilm and a single phase of silica not being formed.
Studies on Microstructures of PAN-ACF Modified by Catalytic CVD
LU An-Hui, ZHENG Jing-Tang, WANG Mao-Zhang
2001, 22(9): 1546-1550.
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PAN-ACF(polyacrylonitrile activated carbon fiber) was firstly impregnated with Ni(NO
3
)
2
·6H
2
Oby using 2-propanol as the solvent. By this method, nickel ion can be dispersed effectively in/on the micropore's entrance or external surface, which were made as an active site for coking to modify the micropore size in a narrower range. The porous structures of PAN ACFwere studied by means of nitrogen adsorption. The micropore size and micropore volume were calculated by Horvath Kawazoe(H-K) equations. The results showed that the ultramicropore concentrated on about 048 nm and the micropore volumes were 019-025 mL/g. The whole pore size distribution was obtained by using density functional theory(DFT). It was shown that the micropore was mainly concentrated on 0.6-0.8 nm. After being washed by acid and deionized water, the sample's BETsurface area and micropore volume were improved and the average pore size kept unchanged, this may be due to the catalyst loaded in the ultramicropore resolved by acid leaving more adsorption space. An X-ray diffractometer(XD-3XA) was used to observed the spectra of samples. It was shown that nickel ion might be effectively dispersed in ACF, the existence of NiOparticles were ascribed to the oxidation by air, and which were dissolved through acid treatment. A-JEM-EX1200 electron microscopy was used to examine the morphologies of PAN ACFs. The SEMresults showed that the sample impregnated with nickel ion could be well distributed by deposited carbon than that without nickel ion. All the results demonstrated that the microstructures of PAN-ACFcould be modified by CVDusing nickel ion as the catalyst for coking.
Theoretical Study on Stabilization and Nonlinear Optical Properties of Configuration Isomer of Schiff Base of the Condensation of Salicylaldehyde with Aniline
LIN Bin-Bin, QIU Yong-Qing, SU Zhong-Min, SUN Shi-Ling, FENG Ji-Kang
2001, 22(9): 1551-1554.
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The energy, structure and nonlinear optical susceptibilities of stable configuration several isomers of were studied by quantum chemical finite field method and semiempirical method. The effect of hydrogen bond and process of hydrogen transfer on stability of the system and nonlinear optical property was discussed. On the basis of those metioned above, the nonlinear optical susceptibilities obtained in this pater were compared with those oblained by ab initio HFmethod. As a result, the shiff base from condensation between salicylaldehyde and aniline bears a better nonlinear optical property, especially the second nonlinear optical property. This kind of compounds will become possibly a nicer optical material.
Advances of Multifunctional D-π-A Dyes System in LB Film
LI Fu-You, HUANG Yan-Yi, HUANG Chun-Hui
2001, 22(9): 1555-1560.
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The dyes with donor-π-conjugated bridge acceptor(D-π-A) structure exhibit a good photoelectric conversion property and excellent second order nonlinearity because they can cause photoinduced intramolecular electron transfer along-π-conjugated bridge. In the same time, the dyes receiving a suitable molecular modification also exhibit an electron conductivity and ion selectivity. The latest advances of multifunctional LBfilm of D-π-Adye systems were reviewed in this paper. The applications about LBfilm of D-π-Adye systems in second order nonlinear optics, photoelectric conversion and conductivity, etc. were specially discussed here.
A New Type of Low Noise Carbon Fiber Nanoelectrodes
HUANG Wei-Hua, PANG Dai-Wen, WANG Zong-Li, CHENG Jie-Ke
2001, 22(9): 1561-1563.
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Anew and facile method has been developed for the fabrication of low noise carbon fiber nanoelectrodes. The carbon fiber was flame fused sealed in a tip of the glass capillary. The carbon fiber microelectrodes were made by cutting the protruding carbon fiber to a desired length, and the carbon fiber nanoelectrodes were achieved by etching the protruding carbon on the flame to form a nanometer scale tip. The tip of carbon fiber nanoelectrodes can be controlled within the range from 100 to 300 nm. Thus no epoxy wax was involved in the carbon fiber sealed-in-glass capillary procedure. The carbon fiber nanoelectrodes were inspected by scanning electron microscopy. The results demonstrated that the surface of the electrodes and the glass/fiber interface are very smooth. Thus the noise caused by the glass/fiber is much lower than that caused by fabricates conventionally. The electrodes were characterized by CVand FSCVmeasurements of the ferricyanide and 5-Hydroxytryptamine(5-HT) neurotransmitters. The results show that the carbon fiber nanoelectrodes have a very excellent electrochemical behaviors and high sensitivity. This experiments offers a new and facile method for the fabrication of carbon fiber nanoelectrodes with very high sensitivity and low noise.
The Effects of Small Organic Additive on Micellar Catalysis
RUAN Ke, ZHAO Zhen-Guo, MA Ji-Ming
2001, 22(9): 1564-1566.
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The effects of isopropyl alcohol, tert-butyl alcohol, isopentyl alcohol, benzaldehyde on the first order rate constant k
1
of the basic hydrolysis reaction of 2,4-dinitrochlorobenzene in the solution of cetyltrimethylammonium bromide(CTAB) are studied. The results show that k
1
decreases with increasing the concentration of small organic additive. It was found that the smaller the alcohol solubility in water and the larger the binding constant with the micelles, the faster the reaction rate decreases. The pseudophase ion-exchange model is applied to quantitatively treat the experimental data. The above results are consistent with that obtained from dynamic light scattering, and are interpreted in terms of the change in micellar structure.
Association of Copolymer Acrylic Acid/Methyl-acrylic acid/Butyl Acrylate in Aqueous Solution
XU Gui-Ying, YANG Yan-Lian, YUAN Shi-Ling, CHEN Ai-Min, ZHENG Li-Qiang
2001, 22(9): 1567-1569.
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The associations of triblock copolymer made of acrylic acid, methyl-acrylic acid and butyl acrylate in aqueous solution as well as in NaCl and CaCl
2
solutions were studied by using fluorescence. The micelle-like clusters(MLCs) of copolymer formed is able to solubilize non polar material. Alittle electrolytes added in the copolymer solution can increase the value of critical aggregation concentration( ρ
ac
) and micropolarity. But with the increase of the concentration of electrolytes, the value of ρ
ac
and micropolarity will decrease. When there is NaCl with fixed concentration in the systems, the process of the MLCs loosening is relaxed because of the charge-screening. In the systems with fixed CaCl
2
concentration, Ca
2+
induced the cross-link of -COO
-
groups, so the interface between the MLCs and the water is not obvious and the big MLCs is formed between the clusters.
An Investigation on Photochemical Reactions of Pentane and Sulfur Dioxide
XU Zi-Li, SHANG Jing, DU Yao-Guo, WANG Ling, GUO Hai-Chen, SHEN Gang, WAN Xiao-Chun, GUO Xiao-Jing
2001, 22(9): 1570-1572.
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The photochemical reaction of pentane and sulfur dioxide were studied. Aseries of gaseous products such as alcohols, ketones, esters, sulfuric anhdride, carbon monooxide, carbon dioxide were identified by GC/MSand GC. The reaction kinetics and reaction mechanism were investigated. The influence of initial concentration of reactant on the photochemical reaction of pentane and sulfur dioxide was studied.
Studies on the Performances of Blue Organic Electroluminescent Device with Different Electron Transport Layers
LI Feng-Hong, TIAN Wen-Jing, WU Fang, ZHANG Zhi-Ming, LI Yan-Qin, MA Yu-Guang, WANG Yue, LI Guo-Wen, SHEN Jia-Cong
2001, 22(9): 1573-1575.
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Blue organic light emitting devices(OLEDs) with Alq, PBD, BBOTor F-OXDas the electron transport layer were fabricated by a high-vacuum multisource-type organic molecular deposition system. The effect of various electron transport layers on the performances of OLEDwas studied. The result indicates that the performances of devices with electron transport layer added between emitter and cathode are increased greatly. It is found that device: ITO/TPD/PPCP/Alq/Al is optimal in structure compared with other devices. Its turn-on voltage is 4 V. Its maximal brightness is 2000 cd/m 2 and its maximal efficiency is 0.36 lm/W.
Studies on the BF
3
·Et
2
O/MCM-41 Solid Acid Catalyst and Its Catalytic Performance
ZHOU Ren-Xian, MO Liu-Ye, ZHAO Shao-Fen, WANG Yue-Juan, ZHENG Xiao-Ming
2001, 22(9): 1576-1577.
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Asolid acid catalyst has been prepared by grafting Boron trifluoride on mesoporous molecular sieve MCM-41 and characterized by XRDand FTIRtechniques. The XRDand FTIRresults indicated that the BF
3
·Et
2
Ointerlocks with the silicon groups of MCM-41 surface to form strong solid acid. The solid acid catalyst would effectively promote the opening of epichlorohydrin with isobutanol to form 1-isobutoxy 3-chloropropanol, and showed a nice activity and selectivity.
Studies on the Thixotropy of Magnesium Aluminum Hydroxide-Kaolinite Suspension
DAI Xiao-Nan, HOU Wan-Guo, LI Shu-Ping, WANG Xin-Fang
2001, 22(9): 1578-1580.
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The thixotropy of suspension, the rheological properties change with the increase of shear time, is a complicated rheological phenomenon. The-shear thinning and the shear thickening phenomena, i.e., positive thixotropy and negative thixotropy, were observed respectively in the previous studies. Recently we found a novel thixotropic phenomenon, described as "complex thixotropy", during studying the thixotropic phenomenon of magnesium aluminum hydroxide montmorillonite suspension. The study of thixotropy of the aqueous suspension consisting of magnesium aluminum hydroxide(Mg-Al-MMH)possessing permanent positive and Kaolinite possessing permanent negative charges is reported. The suspensions studied may display a positive thixotropy and complex phenomenon successively in various Mg-Al-MMH/kaolinite ratios 0-0.16 examined. The effect of shear rate( D
L
)used in measuring viscosity on the thixotropy of the suspension was investigated, and the mechanism of the thixotropy was discussed.
Studies on Growth and Architecture of Self-assembled Multilayers Fabricated from Side Chain Azo Polyelectrolytes
TUO Xin-Lin, CHENG Hao, CHEN Zheng, WANG Xiao-Gong
2001, 22(9): 1581-1586.
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Growth and architecture of self-assembled multilayers, which were fabricated from four side chain azo polyelectrolytes by a layer-by-layer adsorption technique, have been studied. The azo chromophore in side chain was employed as a "probe" to investigate chromophore orientation, desorption and nonlinear growth in the multilayer growth process. All azo polyelectrolytes showed a good self-assembling ability, but the multilayer growth processes were different from one to another. Different pHvaluse resulted in the difference in multilayer growth and architecture, due to this effect on the ionization degree of the polyelectrolytes. The multilayer growth and architecture depend on the adsorption and desorption equilibrium in the systems. The end groups tethered to the azo chromophores, hydrophilic or hydrophobic, showed a significant influence on the multilayer growth. Nonlinear growth appeared at different stages of multilayer formation were found to be related to the substrates, solution properties and polyelectrolyte structures.
Studies on Sequence Distribution of Copolyureas and Relationship of Diamines Reactivity Ratio
DU Zhe-Wei, LIAN Yan-Qing, WANG Xiao-Gong, ZHOU Qi-Xiang, LIU De-Shan
2001, 22(9): 1587-1591.
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Aseries of copolyureas were synthesized by using
1
,6-hexanediamine(HAD), m-phenylenediamine(MPD), 4-aminophenyl ether(DDE), 4,4'-diaminodiphenyl methane(DDM), 4,4'-diaminediphenyl sulfone(DDS) and 2,4-tolyene diisocyanate(TDI). Based on the theory of sequence distribution of copolymers, a method was established which determined the sequence distribution parameters: random degree Band number average sequence length L
na
and L
nb
by
1
H NMRspectra and a computer program for the resolution of overlapping peaks. And the reactivity ratio of diamines with 2,4 TDIwas obtained based on the data. The result was that the diamine reactivity ratio changed in different reacting conditions.
Mechanical Properties of Bombyx mori Silk at Different Temperatures
YANG Yong, CHEN Xin, ZHOU Ping, YAO Wen-Hua, SHAO Zheng-Zhong
2001, 22(9): 1592-1596.
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The mechanical properties of both raw and degummed Bombyx mori silk fibers were carried out by Dynamic Mechanical Thermal Analyzer(DMTA) at different temperatures under precise temperature control. Both stress strain curve and hysteresis loop of single filament were tested. Moreover, the rupture section morphology and inner structure of raw and degummed Bombyx mori silk were examined by SEM, TEMand Raman spectroscopy. The results showed that the initial modulus as well as rupture strength of Bombyx mori silk decreased with the increase of temperature. It was also found that the stretching process induced more β-structure in silk fiber. In addition, sericin was found to perform a worse mechanical property than fibroin.
Polymer Flooding Agent CMC/P(AM-DMDAAC) Formed Through Interpolyelectrolyte Complexation
CHEN Zhe, WANG Qi
2001, 22(9): 1597-1600.
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Oppositely-charged polyelectrolytes, i.e., polyanion cellulose methyl carboxyl(CMC) and polycation poly(acrylamide-dimethyldiallyammonium)[(P(AM-DMDAAC)] were used to form interpolyelectrolyte complexed solution CMC/P(AM-DMDAAC). UV spectra and ionic conductivity measurements showed that polyanion CMCcould complex with polycation P(AM-DMDAAC) in aqueous solution through Coulomb forces. The complex with suitable complexing density is water soluble. The apparent viscosity of the complexed solution increases significantly due to the increased hydrodynamic volume, reaching97.4 mPa·s, 5.2 times that of CMCsolution and 90 times that of P(AM-DMDAAC) solution respectively. The particular structure of complexation endows the complexed solution with better viscosity durability under the condition of high temperature and high shear rate than its constituents polymer solutions.
Preparation of Ultrathin Multilayer Films Containing Poly(4-vinylpyridine) Complex of Osmium and Horseradish Peroxidase and Its Electrochemical Behavior
LI Wen-Jiang, SONG Li-Zhu, SUN Chang-Qing, WANG Zi-Chen, GUO Yu-Peng, ZHAO Chun, Xu Ying-kai
2001, 22(9): 1601-1604.
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We prepared a new kind of multilayer films based on ionic self-assembly technique by successive alternating deposition of positively charged polycation bearing Os complex(PVP-Os) and horseradish peroxidase(HRP) on the surface modified of gold electrode to study the electrochmical behavior and quartz slides to monitor the assembly process by ultraviolet-visible spectroscopy. The electrochemical behavior of the enzyme electrode showed that the multilayer films were stable, electroactive, the mediator PVP-Os as electron shuttle was able to transfer electrons successfully between the active center of the immobilized HRPand the electrode surface.
Synthesis and UV Curing Properties of (Meth)acrylated Dendritic Poly(ether-amide)
WEI Huan-Yu, SHI Wen-Fang
2001, 22(9): 1605-1609.
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Dendritic polymers have received increasing interests from polymer scientists because of the unique structural characteristics, synthetic methods as well as application fields. The (meth)acrylated dendritic poly(ether-amide)s were synthesized by a divergent manner and characterized by
1
H NMR, VPOand FTIRmeasurements. Their UVcuring properties were investigated by Raman, Photo-DSCand DM-TAmeasurements. Over 80% of unsaturation conversion has been obtained for the systems in the presence of a photoinitiator under UVirradiation, and the polymerization rate at peak maximum was promoted with increasing the concentration of double bonds. The softening and glass transition temperatures of their UVcured films were also promoted with increasing the concentration of double bonds.
Surface Photo-oxidation and Photostabilization in Photoinitiated Crosslinking of Polyethylene
WU Qiang, QU Bao-Jun, WU Qiang-Hua
2001, 22(9): 1610-1613.
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The surface photo-oxidation and photostabilization in the photoinitiated crosslinking of polyethylene were studied using Fourier transform infrared spectroscopy(FTIR), X-ray photoelectron spectroscopy(XPS), and the determination of gel content with irradiation time. The data show that the surface photo-oxidation of photocrosslinked polyethylene(XLPE) increases apparently with increasing UVirradiation time. The main photo-oxidation products have been identified as hydroperoxides and various carbonyl compounds. The photostabilization of XLPEcan be realized by suitable pre-irradiation using low pressure mercury(LPM) lamp or by the addition of some hindered amine light stabilizers(HALS). The optimum time of pre-irradiation by LPMlamp is 10 s under the experimental conditions in the present study. However, some HALScan reduce the efficiency of photoinitiated crosslinking process of PE.
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