N_2O在钾改性Cu-Co尖晶石型复合氧化物上的催化分解(英文)

制备了几个不同组成的Cu-Co尖晶石型复合氧化物,用于N2O分解反应,在活性较高的Cu0.8Co0.2Co2O4表面浸渍碱金属盐溶液,制备改性催化剂,考察了碱金属助剂类型、钾前驱物和钾负载量等对改性催化剂活性的影响。用BET、XRD、SEM、XPS等方法表征了催化剂结构。结果表明,几种碱金属碳酸盐改性Cu0.8Co0.2Co2O4的催化活性发生了显著变化,其中,K改性催化剂的活性有明显提高,而Cs的表面改性反而降低了催化剂活性;钾前驱物对K/Cu-Co的催化活性也有较大影响,其中,加入碳酸钾明显提高了催化剂的活性,而加入硝酸钾和醋酸钾反而降低了催化剂活性;有氧无水、有氧有水气氛中,400!C下N2O在碳酸钾改性催化剂0.05K/Cu0.8Co0.2Co2O4上的转化率分别达到了100%和87.6%;该催化剂在400!C下的恒温反应活性和稳定性均高于未改性催化剂。     

钛表面钠氢氧钛纳米线的结构、生物活性和MC3T3-E1细胞响应

采用化学方法处理微弧氧化(MAO)制备的含Si、Ca元素的Ti O2涂层(SC),获得钛氢氧钠(Na0.8H1.2Ti3O7)生物活性纳米线结构。化学处理过程中,SC涂料表面出现了Ca、Na元素溶解,Si元素沉积的现象。化学处理后的SC涂层比SC涂料具有更好的吸水性和诱导磷灰石形成能力。这与处理后涂层(SHTO)特殊的纳米结构有关,在模拟体液浸泡过程中更容易形成Ti-OH。同时,钠氢氧钛纳米线的表面形貌、相组成、OH基团以及良好的湿润能力使其更加适合于MC3T3-E1细胞的粘附和增值。     

铜Ⅱ与α,β-不饱和酸根和安替比林三元配合物的合成、表征、晶体结构和磁性

合成了铜 与丙烯酸根和安替比林及铜 与α 甲基丙烯酸根和安替比林两种三元配合物 ,进行了元素分析、红外光谱、电子反射光谱、ESR谱和变温磁化率等研究 ,确定配合物的组成为Cu2 A4 (C11H12 N2 O) 2 ,其中A =CH2 =CH COO- 、CH2 =C(CH3) COO- ,C11H12 N2 O =安替比林。测定了Cu2 [CH2 =C(CH3) COO]4 (C11H12 N2 O) 2 的晶体结构。晶体属单斜晶系 ;P2 1/n群 ;晶胞参数 :a =1.2 0 2 6 4 (8)nm ,b =0 .876 0 4 (10 )nm ,c=1.882 4 6 (14)nm ,β =10 0 .80 2 (5)° ;Z =2 ;最终偏离因子R =0 .0 30 4。Cu 具有畸变的四角锥形配位环境 ,两个Cu 由四个α 甲基丙烯酸根桥联 ,在Cu 的端位各有一个安替比林分子以O原子配位。Cu Cu 间具有一对称中心 ,Cu Cu 间距离为 0 .2 6 6 15(3)nm。变温磁化率研究表明两种配合物中Cu Cu 间具有强烈的反铁磁性偶合作用     

C3N4/BiVO4/Cu2O复合材料用于纯水中CO2光还原为甲醇

采用分步合成方法将Cu2O纳米颗粒原位还原组装到C3N4/BiVO4表面,设计并合成了 C3N4/BiVO4/Cu2O复合材料.在该过程中,首先将具有光氧化能力的BiVO4与C3N4复合制备出C3N4/BiVO4复合物,进一步通过原位合成法在C3N4/BiVO4复合物表面沉积Cu2O纳米颗粒制备出C3N4/BiVO4/...     

脱硝催化剂中金属Cu的价态变化及其影响因素的XPS研究

考察了X射线光电子能谱(XPS)测试过程中金属Cu改性钒基脱硝催化剂在X射线照射下Cu元素的价态变化及影响因素。结果表明,催化剂中Cu元素以Cu O(Cu2+)和Cu2O(Cu+)两种形式存在,X射线照射会引起Cu O的还原;且初始测得的Cu2O主要为样品焙烧后本征存在的物质。样品中Cu元素还原(Cu O转化为Cu2O)受X射线照射时间与功率、Cu负载量以及样品制备方法等因素的影响:随着照射时间的增加或X射线功率的提高,Cu O还原率均逐渐升高;随着Cu负载量的升高,Cu O还原率整体呈下降趋势,但当负载量达3%后,Cu O的绝对变化量与Cu负载量几乎无关(维持在~1.2%);制备方法中活性组分V元素的存在提高了Cu O的还原活性,而草酸的添加降低了其还原活性。该研究为Cu改性钒基脱硝催化剂的表征分析提供了重要参考,也为其它类似敏感样品的XPS分析提出了测试条件及方法上的建议。     

异烟酰肼缩水杨醛Schiff碱及其铜(Ⅱ)配合物的合成及表征

制备了异烟酰肼缩水杨醛Schiff碱(H2L)及其铜(II)配合物,经元素分析、IR光谱、UV-Vis光谱、电导率和热分析表征,确定了配合物的组成为[Cu(NO3)HL].2H2O,其中H2L=C13H11O2N3.     

铜(II)与α,β-不饱和酸根和安替比林三元配合物的合成、表征、晶体结构和磁性

合成了铜(II)与丙烯酸根和安替比林及铜(II)与α-甲基丙烯酸根和安替比林两种三元配合物,进行了元素分析、红外光谱、电子反射光谱、ESR谱和变温磁化率等研究,确定配合物的组成为Cu2A4(C11H12N2O)2,其中A=CH2=CH-COO-、CH2=C(CH3)-COO-,C11H12N2O=安替比林.测定了Cu2[CH2=C(CH3)-COO]4(C11H12N2O)2的晶体结构.晶体属单斜晶系;P21/n群;晶胞参数:a=1.20264(8)nm,b=0.87604(10)nm,c=1.88246(14)nm,β=100.802(5)°;Z=2;最终偏离因子R=0.0304.Cu(II)具有畸变的四角锥形配位环境,两个Cu(II)由四个α-甲基丙烯酸根桥联,在Cu(II)的端位各有一个安替比林分子以O原子配位.Cu(II)-Cu(II)间具有一对称中心,Cu(II)-Cu(II)间距离为0.26615(3)nm.变温磁化率研究表明两种配合物中Cu(II)-Cu(II)间具有强烈的反铁磁性偶合作用.     

Cu2O/g-C3N4催化合成吲哚-2-羧酸酯

我们通过原位还原的方法将吸附在g-C3N4表面上Cu2+还原,制备出Cu2O/g-C3N4复合材料,并利用XRD、SEM、FT-IR、XPS等分析手段表征Cu2O/g-C3N4.表征结果显示:Cu元素主要以Cu2O的形式吸附在g-C3N4载体上.另外,还考察了Cu2O/g-C3 N4在“一锅法”合成吲哚-2-甲酸乙酯的反应中的催化性能.结果表明:即使在较低的催化担载量和温和的反应条件下,Cu2O/g-C3 N4仍能表现出良好的催化性能并获得44.1％的收率.     

两个由铜离子与Waugh-型阴离子构筑的化合物的合成、晶体结构及表征

以(NH4)6[MnMo9O32]·8H2O为前体原料,与CuCl2及吡啶反应得到了2个Waugh型钼酸盐[Cu(H2O)4]3MnMo9O32·6H2O(1)和[Cu(H2O)4][Cu(C5H5N)(H2O)2]2(C5H5N)MnMo9O32·4H2O(2),并用元素分析、X-射线单晶衍射、红外光谱、固体紫外可见光谱、近红外光谱和热重分析对其进行了表征,并研究了化合物1的磁性质。晶体结构表明,化合物1属于三方晶系,空间群为R32;化合物2属于单斜晶系,空间群为C2/c。化合物1中Cu2+与[MnMo9O32]6-连接形成了三维二重穿插的α-Po拓扑结构。化合物2中单核铜"Cu(H2O)4"和双核铜建筑块"[Cu2(C5H5N)2(H2O)4]"作为桥连接阴离子[MnMo9O32]6-形成了三维网络结构。其中化合物2是首例有机配体参与过渡金属离子配位的Waugh型化合物。     

[Cu2(C2O4)(C12H8N2)2(C3H7NO)2](ClO4)2配合物的合成及其热分解

以邻菲罗啉、2,5二羟基-1,4-二噻烷和Cu(ClO4)2.6H2O为原料,合成了中心对称的双核配合物[Cu2(C2O4)(C12H,N2)2(C3 H7NO)2](ClO4)2(1).通过红外光谱、元素分析等分析测试手段对其进行了表征;借助TG-DTG技术在氮气气氛下研究了配合物的热分解情况,并根据热分析结果确定了...     

Synthesis, characterization and flame retardant of UV-curable hybrid coatings containing SiO2–P2O5–B2O3 via sol–gel method

A ternary sol containing silicon, phosphorus and boron modified by ??-methacryloxypropyltrimethoxysilane was synthesized by sol?Cgel method. The ternary sol was incorporated into the organic matrix and UV-curable organic/inorganic hybrid coating materials were obtained. Hardness, transmittance, haze, cross-cut adhesion and abrasion resistance results showed that the mechanical properties of the hybrid coatings improved effectively with no comprising on optical properties by increasing sol content. Scanning electron microscopy and Energy Dispersive X-ray spectrometer studies indicated that inorganic particles were homogenously dispersed in the organic matrix. The flame retardancy of the UV-curable coatings was investigated by thermogravimetric analysis and microscale combustion calorimeter. The results showed that the incorporation of sol into the organic network led to an improvement in the thermal stability and flame retardancy of the hybrid coating materials. It is a desirable achievement to improve simultaneously both flame retardancy and mechanical properties of the coatings.     

Scratch Resistant and Transparent UV-Protective Coating on Polycarbonate

UV-protective coating material has been developed to improve the scratch resistance and transparency of polycarbonate substrates. Acetyl acetone (AcAc) chelated silanes and 3-glycidoxypropyl-trimethoxysilane (GPTMS) modified nano-titania sols were used for the UV-protective hard coating materials by the sol-gel technique. The hybrid network is formed as a result of the controlled hydrolysis and condensation of the MTMS (Methyl Tri Methoxy Silane) and DMDMS (Di Methyl Di Methoxy Silane). Surface modified TiO₂ nano particles were dispersed in sterically stabilized in the hybrid network by the chelating agent. The coatings dried at 130°C after spray coating were shown to have excellent scratch resistance and adhesion and in addition, it roles as efficient UV-protector under UV irradiation. The long time UV test resulted in no crack formation, without loss of adhesion within the test period of 20 weeks.     

Substrate-Independent Stable and Adherent Reactive Surface Coatings and their Conversion with Amines

Summary: To create stable, adherent and reactive surface coatings, a hybrid polymer composed of poly(methylsilsesquioxane) (PMSSQ) and poly(pentafluorophenyl acrylate) PFPA with a M_n of 32000 g/mol was prepared by a RAFT polymerization procedure. These hybrid polymer has been used for coating experiments. The PFPA part enabled a variable functionalization of the coating afterwards. The stability on various substrates (e.g. glass, PMMA, steel) was tested in an ISO tape test. These reactive surface coatings were modified using different amines, such as amino-terminated PEG, dodecyl amine and N-isopropyl amine. The conversion was analyzed by FT-IR and contact angle measurements.     

The maleimide modified epoxy resins for the preparation of UV‐curable hybrid coatings

In the present study, maleimide‐modified epoxide resin containing UV‐curable hybrid coating materials were prepared and coated on polycarbonate substrates in order to improve their surface properties. UV‐curable, bismaleimide‐modified aliphatic epoxy resin was prepared from N‐(p‐carboxyphenyl) maleimide (p‐CPMI) and cycloaliphatic epoxy (Cyracure‐6107) resin. The structure of the bismaleimide modified aliphatic epoxy resin was analyzed by FTIR and the characteristic absorption band for maleimide ring was clearly observed at 3100 cm^?1. Silica sol was prepared from tetraethylorthosilicate (TEOS) and methacryloxy propyl trimethoxysilane (MAPTMS) by sol–gel method. The coating formulations with different compositions were prepared from UV‐curable bismaleimide‐based epoxy oligomer and sol–gel mixture. The molecular structure of the hybrid coating material was analyzed by ²⁹Si‐CP/MAS NMR spectroscopy techniques. In the ²⁹Si CP/MAS NMR spectrum of the hybrid coating, mainly two kinds of signals were observed at ?68 and ?110 ppm that correspond to T³ and Q⁴ peaks, respectively. This result shows that a fully condensed structure was obtained. The thermal and morphological properties of these coatings materials were investigated by using TGA and SEM techniques. Hardness and abrasion resistance properties of coating materials were examined and both were found to increase with sol–gel precursor content of the coating. The photopolymerization kinetics was investigated by using RT‐IR. 70% conversion was attained with the addition of 15 wt% of BMI resin into the acrylate‐based coating formulation. It was found that the UV‐curable organic–inorganic hybrid coatings improved the surface properties of polycarbonate. Copyright © 2009 John Wiley & Sons, Ltd.     

镍基彩色电沉积Cu_2O椭圆偏振光谱研究

应用电化学方法在Ni基底上沉积Cu2O彩色膜层以期提高装饰效果.X光电子能谱(XPS)、扫描电子显微镜(SEM)和能量色散谱(EDS)测试表明,膜层由Cu2O组成,沉积层光滑平整,且Cu2O层均匀覆盖Ni基底.椭圆偏振光谱表征不同沉积时间的膜层,提出膜层内存在由Ni逐渐变为Cu2O的过渡层,建立"空气—Cu2O层—过渡层—Ni基底"4层膜模型,并借助梯度有效介质近似解析椭圆偏振光谱,得到不同沉积时间的膜层厚度以及厚度随时间线性增长关系.     

Synthesis and characterization of polydimethylsiloxane-cured organically modified silicate hybrid coatings

Hybrid coatings based on polydimethylsiloxane-cured organically modified silicate were synthesized through a sol-gel technique. Amino-terminated siloxane, 3-glycidoxypropyltrimethoxysilane and tetraethoxysilane were used as precursors for the hybrid coatings. These hybrid films were deposited via spin coating onto an aluminum alloy to improve the corrosion protection. The effects induced by the different chain lengths of siloxane on the chain dynamics, thermal stability and corrosion performance of the coated samples were investigated. The rotating-frame spin-lattice relaxation times and scale of the spin-diffusion path length indicated that the configuration of the hybrid films was highly crosslinked, dense and adhered to the aluminum alloy substrates. The thermal stability and the apparent activation energy, evaluated by van Krevelen's method, of the hybrid coatings depended on the siloxane chain length. Potentiodynamic analysis revealed that the hybrid films provided exceptional barrier and corrosion protection in comparison with untreated aluminum alloy substrates.     

Effects of coating composition and surface pre-treatment on the adhesion of organic-inorganic hybrid coatings to low density polyethylene (LDPE) films

Organic-inorganic hybrid coatings, obtained through the sol-gel chemistry from tetraethoxysilane and polyethylene-poly(ethylene glycol) block copolymer, have been prepared in different compositions and applied to untreated and plasma treated LDPE films by spin coating. The mechanical properties of the coatings and the adhesion between coating and substrate have been characterized by fragmentation test. An increase in coating strength, elongation at break and adhesion has been observed with increasing the organic fraction in the hybrid coating. A plasma treatment of the LDPE surface, just before the application of the coating, lead to an increase of the adhesion between coating and substrate (interfacial shear strength), leaving almost unaffected coating strength and strain at fragmentation onset.     

Structure and tribological properties of Cu–PU–PTFE composite coatings prepared by low‐energy electron beam dispersion with glow discharge

Polytetrafluoroethylene (PTFE) composite coatings doped copper acetate and polyurethane (PU) were prepared on rubber substrate by low‐energy electron beam dispersion technique. The effects of dopant and glow discharge treatment on the surface morphology, structure and tribological properties of the coatings were investigated. The results showed that Cu–PTFE composite coatings form uniform surface and dense column structure with spherical aggregations under glow discharge treatment. PU coating shows the large size of protuberance structure but PU–PTFE coating presents spherical structure. Both of the coatings become relative dense and smooth after discharge treatment, and Cu–PU–PTFE composite coatings possess a smoother surface and lower polar component of surface energy. Cu doping weakens the crystallinity and ordering degree of composite coatings, but glow discharge increases the ordering degree and branched structure of C―H groups. Friction experiment indicated that Cu fails to improve the wear resistance of PTFE coatings but glow discharge treatment can do it. Cu–PU–PTFE coatings after discharge treatment have the higher wear resistance and lower coefficient of friction. Copyright © 2016 John Wiley & Sons, Ltd.     

Inorganic–organic sol gel hybrid coatings for corrosion protection of metals

Inorganic–organic hybrid coatings by sol–gel process are very suitable for fighting corrosion. Inorganic sols in hybrid coatings not only increase adhesion by forming chemical bonds between metals and hybrid coatings, but also improve comprehensive performances of polymer in the coatings. Different organic polymers or organic functionalities are introduced into gel network to achieve tailored properties, such as hydrophobic properties, increasing cross-linking density, etc. As for corrosion protection of metals organic components of hybrid coatings are selected to repel water and form dense thick films and reduce coating porosity. The factors, such as the ratio of inorganic and organic components, cure temperature, pigments in hybrid coatings, need to be optimized for attaining hybrid films with the maximum corrosion resistance. Electro-deposition technique offers relatively thick homogeneous defect-free hybrid coatings in comparison to dip or spin coating techniques. Green cerium ions and non-ionizable organic inhibitors are more developed in hybrid coatings nowadays than other corrosion inhibitors. Long-term corrosion resistance techniques of inhibitors are discussed. The inhibitors entrapped in the nanocontainers are doped in hybrid films to prolong release of the inhibitors to damaged zones, which is discussed in detail. Among all the nanocontainers of corrosion inhibitors the prospective techniques which show superior corrosion protection are cyclodextrin/organic inhibitor inclusion complexes and layer by layer assembly of organic corrosion inhibitors in nanocontainers. Super-hydrophobic property of hybrid coatings derives from low surface tension and surface roughness of hybrid coatings, which endues the films with excellent corrosion protection for metals, but the durable property of super-hydrophobic coatings needs to be improved for industrial application. An ideal multiple model of hybrid coatings for superior anti-corrosion of metals proposed is a combination of super-hydrophobic hybrid coatings and underlying hybrid coatings doped with sustained release of corrosion inhibitors on metal substrates.     

Synthesis, infrared stealth and corrosion resistance of organically modified silicate-polyaniline/carbon black hybrid coatings

Hybrid coatings based on organically modified silicate-polyaniline/carbon black (Ormosil-PANI/CB) were synthesized through a sol-gel technique with different carbon black (10-30 wt%) and PANI/CB (10-30 wt%) contents. These hybrid films were deposited via spin coating onto an aluminum alloy in order to improve the corrosion protection and to act as infrared stealth coatings. The effects induced by the PANI/CB composites on the chain dynamic, thermal properties, infrared stealth, and anticorrosion performances of the coated samples were investigated. The rotating-frame spin-lattice relaxation times and scale of the spin-diffusion path length indicated that the configuration of the hybrid films was highly cross-linked and dense. Thermal properties of these Ormosil-PANI/CB hybrids have been improved over the pure Ormosil analyzed by thermal gravimetric analysis (TGA). The thermal extinction of the hybrid coatings increased with the increase in the carbon black and PANI/CB content. Potentio-dynamic and salt-spray analysis revealed that the hybrid films provided an exceptional barrier and corrosion protection in comparison with untreated aluminum alloy substrates.