阳离子型双子表面活性剂的合成及表面活性

合成了一种季铵盐型双子表面活性剂Gem in i 12-3-12,采用红外光谱、元素分析和两相滴定法对其结构和纯度进行了分析,测定了不同浓度表面活性剂水溶液的表面张力,并得到临界胶束浓度(CMC)、饱和吸附量(Γm ax)、单分子饱和吸附面积(Am in)。结果表明,Gem in i 12-3-12的收率为77.2%,纯度为98.4%,它与相应的单尾基十二烷基三甲基溴化铵(DTAB)的表面活性相当,但CMC比DTAB低14倍左右。     

Adsorption isotherms of sesame oil in a concentrated miscella system

The adsorption of peroxides, unsaturated carbonyls, free fatty acids and carotenoids from unrefined sesame oil on vegetable carbon (5%, w/w) in a miscella system was studied. Three different solvent conditions (hexane/ethanol, 100:0, 95:5 and 75:25, vol/vol), combined in a factorial design with five levels of solvent (0, 10, 20, 30 and 40%, w/w), were used to develop the miscella. Equilibrium adsorption was not achieved during the 100 min of adsorption, mainly because the oil components were involved in oxidation reactions during the adsorption process. However, for a given solvent concentration, adsorption of the oil components showed a significant linear regression on their respective initial concentration in the miscella (C_i). Peroxides and carbonyls showed, at all solvent levels investigated, an affinity for the carbon more independent of their C_i than free fatty acids and carotenoids. In general, at the same C_i, a higher adsorption was achieved as solvent concentration increased. The results indicated that free fatty acid adsorption may depend on competitive adsorption based on molecule hydrophobicity. However, in spite of the higher hydrophobicity of carotenoids, compared with free fatty acids, they might not be competing for the same adsorbing sites. Ethanol showed a prooxidant effect that increased peroxide production during adsorption but did not affect the reaction involved in carbonyl production.     

莠去津的生态毒理学及其环境行为学研究进展

莠去津是世界范围内广泛使用的除草剂,在曾经使用莠去津的地区的水体中均检测到莠去津的残留,由于莠去津属于内分泌干扰物,长期暴露在该有机污染物的环境中,势必对各种生物产生不良影响。介绍了莠去津的生态毒理学研究进展及其环境行为研究的内容和热点,着重评述了莠去津对哺乳动物的各种毒性、在土壤中的吸附机制和迁移以及治理措施。     

Effect of charge density,molecular weight,and hydrophobicity on polycations adsorption and flocculation of polystyrene latices and silica

Adsorption and flocculation behavior of two series of synthetic polycations was investigated in dispersions of silica and polystyrene latices with various particle size and surface charge densities. Polycations of the first series (polydiallyldimethyl ammonium chloride‐PDADMAC) varied in molecular weight only, while polycations of the second series (derivatives of polymethacrylic acid) varied in both molecular weight and hydrophobicity. We have found that maximum adsorbed amount of high molecular weight PDADMAC on latex particles was nearly independent of the surface charge density when the particle size was comparable to the polymer coil dimensions in solution. Both low and high molecular weight PDADMACs were efficient flocculants, although significantly lower amounts of high molecular weight polyelectrolyte were required for the phase separation in the dispersions due to particles aggregation through “charge patch” mechanism. The increase of polymer hydrophobicity leads to higher adsorbed amounts and broadening of flocculation window by polycations of the second series on both substrates. However, no strong enhancement of segment–surface interactions on hydrophobic substrates was observed. Since formation of multilayers upon adsorption was also excluded, the difference in adsorption and flocculation behavior was related to the more compact conformation of hydrophobically associating derivatives in solution and at the interface. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3422–3429, 2006     

Study of the sorption and acidic properties of MTW-type zeolite

The acidity of H-MTW-type zeolite has been investigated using infrared spectroscopy of adsorbed pyridine. Pore volume has been measured by nitrogen andn-hexane adsorption. The zeolite exhibits infrared signals at 3612 and 3580 cm^–1 tentatively attributed to bridging hydroxyl groups vibrating in the main channel and in the six-membered rings of the structure, respectively. Both hydroxyl groups possess high acid strength and are readily accessible to pyridine. H-MTW shows an-hexane cracking activity at 350°C comparable to that obtained with MFI and BEA-type materials with a product selectivity between medium and large pore structural types.     

改性活性炭的表面特性及其对苯酚的吸附性能

研究了表面改性对活性炭吸附苯酚性能的影响。研究发现,硫酸氧化可增加活性炭表面酸性基团的含量,提高了活性炭的表面亲水性,降低pHPZC值,因而对吸附水中的苯酚的性能产生明显影响,降低了对苯酚的吸附。     

非常规汽油脱硫技术

水蒸气脱硫是一种以水代替氢的脱硫方法,降低脱硫成本显著。以酶代替传统加氢催化剂的生物脱硫技术是一个引人注目的课题。结合催化和精馏的催化精馏脱硫法,在选择脱硫的对象上,相对传统的催化脱硫更具优势。萃取脱硫是采用一些极性溶剂混合物脱除汽油馏分中的硫化物,须加入氧化助剂才有较好的脱硫效果,由此将导致大的辅助车间和有限脱硫效率。膜过程脱硫、声化学脱硫、等离子体和光脱硫都属于物理方法,环保意义很大。对于吸附脱硫,从流化催化裂化汽油中除硫完全,而汽油产率降低很少,辛烷值几乎没有损失,是一种有前途的脱硫方法。     

Molecular design and characterization of catalysts for NO x selective reduction by hydrocarbons in the oxygen excess based upon ultramicroporous zirconia pillared clays

Approaches to design of zirconia pillared clays via control of the properties of pillaring species in solutions were elaborated. Structural features of pillars and Pt + Cu active components fixed at these nanoparticles were shown to determine catalytic properties of pillared clays in NO_x selective reduction by hydrocarbons in the oxygen excess.     

阳光下TiO2/GAC光催化处理洗涤剂废水的研究

利用太阳光作光源，采用固定在颗粒活性炭中的TiO2(TiO2／GAC)作光催化剂，利用其将活性炭极好的吸附性与TiO2优良的光催化性能结合于一体的特性，设计了对以洗衣粉配置的洗涤剂模拟废水的两种处理方案：同时光照-吸附法和吸附饱和-光照水洗再生法，并在实验基础上对两种方案的一些性能进行了讨论。     

EPR Study of CO Adsorption onto CoZSM-5 Zeolite: Evidence for Spin Crossover upon Coordination and |z2, 2A1〉 Ground State

Adsorption of CO onto dehydrated cobalt-exchanged ZSM-5 zeolite was studied by CW-EPR techniques. It is shown that the reversible formation of a low spin carbonyl ¹{Co(CO) _n }⁷ adduct upon addition of carbon monoxide at p _CO>50–60 Torr involves significant change in the spin state of Co²⁺ from S=3/2 to 1/2. The spin Hamiltonian parameters of the adduct g _x =2.222, g _y =2.184, g _z =2.011, |A _x |=3.8 mT, |A _y |=3.2 mT, |A _z |=7.9 mT were determined by a computer simulation and further discussed in terms of the possible ground state and molecular structure. It is shown that the ¹{Co(CO) _n }⁷ cage complex exhibits a C_2v symmetry with |z ²,²A₁ ground state.