高粘结强度淀粉粘合剂的研究

探讨了淀粉粘合剂的氧化反应机理、生产工艺条件及配方设计原则。该粘合剂采用快速冷却生产新工艺,室温条件下反应仅需一小时。产品粘结强度大,可以代替聚乙烯醇粘合高档彩盒;贮存两个月不凝聚、不霉变。     

X射线光电子能谱研究活性碳纤维表面结构

研制了各种不同结构的活性碳纤维。并用 X 射线光电子能谱对元素组成、相对含量、表面官能团类型以及原料、制备工艺的关系进行了全面的研究。用曲线拟合分峰技术对谱峰进行了数学处理。结果表明,C 和 O 是活性碳纤维的基本元素。采用不同原料和制备工艺,活性碳纤维表面还含有少量的 N、P、Ca 等杂原子。纤维表面碳大部分为类石墨碳,C—H是活性碳纤维一种不可忽略的基团。氧元素主要与碳生成表面含氧基团如 C—OH、C=O、C(?)及酯等。C—OH 与基体碳有一定程度的共轭。表面的氮主要以胺基或亚胺基形式存在。磷的结合态有氧化磷以及各种磷酸盐。未经活化的碳纤维,含氧官能团的含量及总含量不比相应活性碳纤维低,个别样品还高。活化过程的脱羧反应是导致活性碳纤维生成高比表面积的根本原因,提高活化温度或增加活化剂浓度时,活性碳纤维表面含氧量反而下降。     

MCM-41负载氧氮化钼的制备和表征

将MoO3和介孔材料MCM-41的机械混合物热处理得到MoO3／MCM-41复合体，将MoO3／MCM-41在氨气氛中于700℃氮化处理3h，制备了氧氮化钼负载的MCM-41催化材料。用XRD，XPS和氮吸附-脱附等手段表征了该材料。结果表明：在XRD图谱中出现氧氮化钼的微弱衍射峰，证明通过这种方法得到的材料中的氧氮化钼呈现结晶趋势。XPS谱表明：Mo存在多种化学状态。氧氮化钼负载的MCM-41的比表面积，孔体积和孔径等参数小于MoO3／MCM-41和纯MCM-41的值。     

几种碳纤维表面酰氯化处理及XPS表征

通过先酸氧化、后酰氯化处理，研究了T300、T800和某国产型号碳纤维3种碳纤维的表面活性。利用X射线光电子能谱（XPS）对酸氧化及酰氯化处理后的样品进行了表面化学性质分析。结果表明，酸处理后T300表面-COOH含量最高，为14，50％，酰氯化处理后表面Cl元素含量也最高，为3．88％，Cl元素与T300样品表面以酰氯共价键形式（COCI）结合。     

几种碳纤维表面酰氯化处理及XPS表征

通过先酸氧化、后酰氯化处理,研究了T300、T800和某国产型号碳纤维3种碳纤维的表面活性.利用X射线光电子能谱(XPS)对酸氧化及酰氯化处理后的样品进行了表面化学性质分析.结果表明,酸处理后T300表面-COOH含量最高,为14.50%,酰氯化处理后表面Cl元素含量也最高,为3.88%,Cl元素与T300样品表面以酰氯共价键形式(COCl)结合.     

CF/PPES界面结构的XPS表征

复合材料中增强材料与基体间的界面具有复杂的结构，具有传递应力的能力。通过对界面结构的研究和表征，促进对复合材料界面近程结构的认识，扩大其应用领域。利用X射线光电子能谱(XPX)研究了碳纤维／杂萘联苯聚醚砜(CF／PPES)的界面状态和结构，证明了CE／PPES的界面上确有新的化学结构出现，使CF／PPES的宏观性能优异。     

活性碳纤维表面氧化还原机理研究

用X射线光电子能谱分析技术,研究了氧化还原反应前后ACF表面结构的变化以及反应条件与结构变化的关系。结果证明ACF的氧化还原反应机理至少包括两种反应过程,一为增加C—OH基团浓度的反应,二为增加C=O基因浓度的反应。在强烈的氧化条件下,还会发生部分基因最终被氧化成为二氧化碳的反应。当表面含氧基团浓度达一定值时,同种氧化剂进一步氧化不会明显增加含氧量,但改用更强的氧化剂时,表面含氧量会增大到另一新的平衡值。ACF表面存在一系列电极电位不同的氧化还原反应中心,在不同氧化还原体系中,ACF表面参与反应的基因种类和浓度都不一样。     

滤料表面活性滤膜对水中锰的吸附特性与机理研究

以中试滤柱中石英砂表面充分覆盖的复合氧化物活性滤膜为对象,通过研究活性滤膜对水中Mn2+的吸附特性,探讨其吸附水中Mn2+的机理;结合光电子显微镜对滤膜比表面积及孔道测定结果,对滤膜形貌与物理结构进行了表征;通过X射线光电子能谱(XPS)对Mn2+在滤膜表面的吸附活性位进行了初步研究。结果表明,Mn2+吸附过程符合Lagergren拟1级动力学方程(R2>0.95);随着水中Mn2+初始质量浓度ρ0的增加,平衡吸附量Se逐渐增大;活性滤膜对Mn2+吸附等温曲线符合Langmuir方程(R2=0.943 4),满足单分子层化学吸附的模型;滤膜成熟后,滤料比表面积、总孔容和孔径显著增加,吸附Mn2+的能力明显加强;当水中Mn2+的质量浓度为0～5 mg/L时,可用Se/(mg.g-1)=[0.02781ρ0/(mg.L-1)]+0.027 12测算活性滤膜对Mn2+的吸附量。通过XPS测定活性滤膜吸附Mn2+前后表面元素原子结合能的变化,确定了活性滤膜表面Mn2+吸附活性位为复合氧化物中Fe-O和Mn-O的O原子。     

头发与头皮护理的科学基础（Ⅱ）——头发的谱学表征技术

当前发用品的开发与研究过程中,人们往往较多关注于光泽、梳理性、蓬松度、力学性能等表观性能的评价与检测上,而对表观性能背后头发在分子层面上的变化研究较少。随着现代光谱学技术的发展,红外光谱、拉曼光谱、X射线光电子能谱与X射线荧光光谱等已被广泛应用于头发的相关研究中,为头发内部成分差异、不同环境下的损伤情况以及护发新原料的作用机理提供了大量分子层面的解释和科学证据支持。基于此,本文介绍了常用于头发表征的光谱学技术,对样品制备、表征仪器、数据分析方法等内容进行了总结与梳理,阐述了头发内部不同区域的化学组成差异,列举了数个基于谱学表征证据分析头发性质与结构之间的关系的案例,以期为护发新原料、新产品的开发提供参考。     

新型高分子亚砜树脂的合成及表征方法研究

实验将交联氯甲基化聚苯乙烯树脂进行改性,与巯基化合物反应合成一种新型高分子亚砜树脂,用FT-IR光谱法、NMR核磁共振碳谱、XPS能谱等方法表征了该化合物的结构组成.分析表明,该方法可以成功地对氯甲基聚苯乙烯树脂进行接枝改性,使其具备亚砜化合物的性质,可以利用亚砜与贵金属络合的反应机理对贵金属分离富集.     

Influence of silane-based treatment on adherence and wet durability of fusion bonded epoxy/steel joints

Three layers polyolefin coatings are widely used in Europe to protect pipelines against corrosion. Loss of adhesion at a fusion bonded epoxy (FBE)/steel interface has occasionally been observed even on pipelines without external defects. Silane-based surface pre-treatments are developed to improve adhesion with limited impact on the environment unlike usual chromate conversion pre-treatments; however the mechanisms involved in silane action need to be more deeply understood. The application process of silane surface treatment implies a series of key parameters of which optimization is imperative to form a silane layer with good properties at the interface. This paper studies the influence of the cure temperature and the pH of an aminosilane based pre-treatment on adhesion strength and durability via single lap shear tests. SEM/EDX, FT-IR and XPS analyses are used to characterize the silane and silane/epoxy structures. Silane pretreatment improved the FBE joints durability and appears as a relevant solution to replace the usual chromate conversion pretreatments. The joints pretreated at pH 10.6 had better durability than at pH 4.6. This was related to the formation of a bridge across the silane/epoxy interface at pH 10.6, whereas, at pH 4.6, formic acid reacts with amino groups of silanes, limiting the reaction between amino groups and epoxy.     

Study of chemical activation process of a lignocellulosic material with KOH by XPS and XRD

Chemical activation of carbons is currently a very common method for obtaining activated carbons with very high surface areas. KOH is one of the most effective agents employed for this purpose. However, the reaction mechanism of this kind of activation it is not yet completely elucidated, although some models have been proposed. In this paper, an activated charcoal was obtained from a lignocellulosic material by impregnation with different amounts of KOH. The activation process was studied by X-ray photoelectron spectroscopy and X-ray diffraction. These techniques point to the formation of different potassium compounds at the carbon surface (mainly K₂CO₃ and different oxides) and show the dependence between surface area development in the carbons and the amount of K₂CO₃ formed during the activation process.     

Influence of Li doping on the morphological evolution and optical & electrical properties of SnO2 nanomaterials and SnO2/Li2SnO3 composite nanomaterials

SnO₂ nanomaterials and SnO₂/Li₂SnO₃ composite nanomaterials doped with different Li contents were synthesized via a simple one-step thermal evaporation method. X-ray diffraction patterns showed that with the increase of Li doping, the intensity of Li₂SnO₃ diffraction peaks gradually increased, while that of SnO₂ diffraction peaks gradually decreased. With the increase of Li doping, the width of nanobelts gradually increased, with the morphology changing from banded structure to standard hexagonal sheet structure. The Raman scattering spectra indicated that with the increase of Li doping, the peak of Li₂SnO₃ at 588.8 cm^?1 kept increasing, and the strongest vibration mode A_1g in SnO₂ gradually weakened. X-ray photoelectron spectroscopy revealed that with the increase of Li doping, the surface electrophilic oxygen species in SnO₂/Li₂SnO₃ composite nanomaterials greatly increased. Under the condition of light irradiation with a wavelength of 505 nm, the bright current of the Li-doped SnO₂ samples was higher than the dark current, while that of the SnO₂/Li₂SnO₃ composite nanomaterials was higher than the dark current, which was mainly due to more oxygen vacancies in SnO₂/Li₂SnO₃ composite nanomaterials than electrons excited by light. Consequently, positive photoconductivity gradually weakened, and even the negative photoconductivity emerged.     

Oxidative functionalization of carbon nanotubes in atmospheric pressure filamentary dielectric barrier discharge (APDBD)

The surface compositional and any structural changes that occur on carbon nanotubes using air-atmospheric pressure dielectric barrier discharge (APDBD) for functionalization are investigated employing Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis (TGA), X-ray diffraction (XRD), and neutron diffraction techniques. Atmospheric pressure plasmas (APP) are suggested to be particularly suitable for functionalization of aligned nanotubes, where wet chemical manipulation could damage or even destroy the highly desirable vertical alignment. In this work a detailed experimental study elucidating the effects of APDBD plasma treatment parameters (e.g. power density, discharge composition, inter-electrode gap and treatment time) on the electronic structure, physical, and chemical behaviour of carbon nanotubes has been conducted. In an atmospheric air we find an optimal oxidative functionalization of CNTs in our DBD system within few seconds (<5 s) at a discharge power of ∼0.5 kW. This investigation may find useful application as functionalization technique for CNT engineered devices and sensors.     

Molecular structure of interfaces between plasma-polymerized acetylene films and steel substrates

Plasma-polymerized films of acetylene were deposited onto steel substrates in an inductively coupled reactor by exciting the plasma in an argon carrier gas and then injecting the monomer into the afterglow region. The molecular structure of the film/substrate interface was determined using reflection–absorption infrared spectroscopy (RAIR) and X-ray photoelectron spectroscopy (XPS) to characterize the films as a function of thickness. RAIR showed that thick (∼ 900 Å) as-deposited plasma-polymerized acetylene films had a complicated molecular structure and contained methyl and methylene, mono- and disubstituted acetylene, vinyl, and cis- and trans-disubstituted olefin groups. Evidence of oxidation resulting from the reaction of trapped radicals with atmospheric oxygen and moisture to form O—H and C=O groups was also obtained. The molecular structure of thin films (∼ 60 Å) was similar although evidence was obtained to indicate that acetylide groups (H—C≡C⁻) were present at the film/substrate interface. Results obtained using angle-resolved XPS analysis showed that carbonaceous contamination was removed from the substrate and that oxides and hydroxides on the substrate surface, especially FeOOH, were chemically reduced during deposition of the films. XPS also confirmed that plasma-polymerized acetylene films deposited on steel substrates contained groups. Preliminary results also showed that films deposited in an inductively coupled reactor were good primers for rubber-to-metal bonding, whereas films deposited in a capacitively coupled reactor were not. The differences may be due to the wide variety of functional groups found in the former type of films but not in the latter. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 1283–1298, 1998     

Determination of the Molecular Structure of Interphases Between Epoxy/4,4'-Diaminodiphenylsulfone Adhesives and Silver Substrates Using SERS and XPS

The molecular structure of interphases formed by curing an epoxy/4,4'-diaminodiphenylsulfone (DADPS) adhesive against rough silver substrates was determined using surface-enhanced Raman scattering (SERS) and x-ray photoelectron spectroscopy (XPS). SERS spectra obtained from the adhesive deposited onto silver island films were very similar to SERS spectra obtained from the DADPS curing agent spun onto silver island films, indicating that DADPS in the adhesive system segregated to the interphase and was preferentially adsorbed onto the silver substrate. Differences in the relative intensity of several bands in the normal Raman and SERS spectra of DADPS were observed. For example, the band near 1603 cm^-1 was stronger in SERS spectra of DADPS than in normal Raman spectra. The band near 1150 cm^-1 was weaker in SERS spectra of DADPS than in normal Raman spectra. These results implied that DADPS was adsorbed through one of the NH groups with an end-on conformation. Consistent results were also obtained from XPS spectra. C(ls) spectra of the adhesive and silver fracture surfaces of specimens prepared by curing the adhesive against silver substrates were more similar to the C(ls) spectra of DADPS than to those of the bulk adhesive. These results confirmed the preferential adsorption of DADPS onto the silver substrate from the adhesive system. The similarity of the C(ls) spectra obtained from adhesive and silver fracture surfaces indicated that a thin DADPS-rich interphase was formed between the bulk adhesive and the silver substrate and that the locus of failure was partially within this layer. However, less nitrogen and sulfur were detected on the silver fracture surface than on the adhesive fracture surface. A large amount of silver was observed on the substrate fracture surface and a trace was found on the adhesive fracture surface. These results indicated that failure of the adhesive joints was within the interphase but near the silver substrate. No evidence of chemisorption of DADPS onto the substrate was observed.     

Transformation of doped Fe in pitch sphere in carbonization and activation processes

Ferrocene was added into the starting pitch in order to produce the pitch-based spherical activated carbon with mesopore (PSAC-M) forms of doped Fe in different stages—stabilization, carbonization, and activation—during the preparation process of the PSAC-M being analyzed using Mössbauer spectroscopy (MES), X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). Ferrocene was oxidized into -Fe₂O₃ at the stabilization step. The major portion of -Fe₂O₃ was reduced into -Fe during carbonization at 900°C, which was subsequently transformed into Fe₃C by 1200°C. No obvious sintering or agglomeration of iron particles occurred during carbonization process even when the carbonization temperature was as high as 1200°C. The activation re-oxidized -Fe into γ-Fe₂O₃, which aggregated and grew up along with the activation time and iron content.     

The structure of Cu- and Cd-UPD-layers on a stepped Pt(533) single crystal surface studied by grazing incidence XAFS, XRD and XPS

Small two-dimensional clusters and linear nanostructures of copper and cadmium were prepared electrochemically on the stepped surface of a (533) Pt single crystal. The deposition was performed under potentiostatic conditions in a solution of 0.001 M CuSO₄ or 0.005 M CdSO₄ in H₂SO₄ in the potential range of under potential deposition (UPD). The surface was examined with X-ray photoelectron spectroscopy (XPS) for quantification of the deposited amount. Grazing incidence X-ray absorption fine structure (GIXAFS) and grazing incidence X-ray diffraction (GIXRD) were used for determination of the adsorbate structure. The X-ray absorption and X-ray diffraction experiments were performed in-situ within the electrolyte at X-ray beam lines at HASYlab (DESY, Hamburg). Combining the results of the different methods, it was possible to reveal the structures of the metal adsorbates at several characteristic potentials in the UPD range.     

X-ray absorption near-edge structure and photoelectron spectroscopy of single-walled carbon nanotubes modified by a HBr solution

X-ray absorption near-edge structure (XANES) spectroscopy and photoelectron spectroscopy (PES) have been used to investigate single-walled carbon nanotubes (SWNTs) modified by immersion in a HBr solution at room temperature. After treatment XANES spectra of SWNTs show a new pronounced feature, which has been assigned to new bonds between the sidewall of the SWNTs and Br atoms. This investigation demonstrates the unique capabilities of the XANES spectroscopy as a tool to achieve structural and bonding information of carbon nanotubes induced by chemical processes.