老化丝织品的红外光谱分析研究

古代丝织品老化程度的检测有助于了解丝织品的保存状况及保护方法的选择与改进,通过红外光谱分析对丝织品老化原因及程度进行了研究。样品为经光老化、热老化和水解老化的白色丝织品和出土于湖北、内蒙古、青海的古代丝织品。对这些样品进行了显微红外分析,结果表明,红外光谱分析虽然只是提供半定量分析,但是对于发生了水解老化的丝织品来说,由于羧基含量的增加,红外分析能很容易提供定性及较好的半定量的分析结果,因此对于出土古代丝织品保存状况及老化机理的研究来说很有实用价值。     

浙江三个新石器时代遗址出土玉玦科技分析

玉玦是我国新石器时代广泛出现的一类重要玉器。环太湖流域新石器时代遗址中出土的大量玉玦,具有鲜明时代和地域特征,为探索中国玉文化起源和传播提供了重要实物。为获取环太湖流域新石器时代玉玦的基础材料学信息(如主要矿物组成、硬度等),以及探索玉料随时间演变规律和可能的原料来源,本文以浙江省境内3个代表性新石器时代遗址--田螺山、仙坛庙和江家山遗址出土的玉玦为研究对象,采用X射线衍射(XRD)和质子激发X射线荧光(PIXE)分析技术对其进行了无损分析检测。研究结果表明： 从河姆渡文化至崧泽文化晚期,所分析玉玦的主要组成矿物为萤石、迪开石、石英、白云母、透闪石和蛇纹石等,以萤石、玉髓和迪开石为主,且时代早于透闪石和蛇纹石。结合已有的研究成果,探讨了相关遗址出土玉玦的原料随时间变化特征、原料来源,以及玉玦的材料学特征与加工工艺之间的内在联系。     

葡萄藤材的微纤丝角与结晶度研究

为了解葡萄藤材的基本材性,提高我国非木材类植物资源高附加值加工利用水平,应用X射线衍射法测定了葡萄藤材的微纤丝角和结晶度。结果表明:微纤丝角变化范围在38.4—50.0°之间,平均值约为44.1°,与木材的微纤丝角相比偏大;纤维素结晶度变化范围在32.6%—41.0%之间,平均值约为37.4%,与木材的结晶度相比偏小。实验为葡萄藤材的加工利用提供了理论依据。     

不同产地软玉的拉曼光谱分析及在古玉器无损研究中的应用

利用拉曼(Raman)光谱技术分别对中国新疆、青海、江苏、辽宁及韩国、俄罗斯、加拿大、新西兰和澳大利亚的软玉样品进行无损分析研究。首先利用拉曼光谱区分了透闪石型和阳起石型软玉, 并对软玉双链结构中Na+、K+对Ca2+以及Al3+对Si2+的不同置换程度引起低频区域特征峰的漂移进行分析, 同时还研究了表面状态和显微结构对674cm-1附近峰强的影响。最后利用拉曼(Raman)光谱技术结合质子激发X射线荧光(PIXE)和X射线衍射(XRD)对河南安阳殷墟遗址、河南省洛阳地区和浙江良渚遗址出土的9件中国古代玉器进行透闪石型软玉的矿相标定, 证明拉曼光谱在中国古玉器结构测试和材质鉴定中是一种很好的无损分析手段。     

XRD与NMR的热处理竹材结晶性能研究

木质纤维素的结晶度研究方法较多,但目前观点不一。采用三种不同的热处理方法(稀酸,碱及甘油高温处理)并基于X射线衍射(XRD)和固体核磁共振技术(CP/MAS 13 NMR),综合研究竹材结晶度变化规律,通过X射线衍射参数及高斯函数曲线分析结晶纤维素C-4区域的信号面积分析,获得不同的化学热处理介入下竹材化学成分及结晶度变化机理。结果表明:经过化学热处理后,竹材的结晶度指数总体增加,碱处理002峰尖锐程度增大,并向大角度方向偏移明显,002晶面宽度变大,结晶区层间距尺度变小。CP/MAS 13 NMR与XRD结果基本一致,但是计算值偏小。未处理竹材在84.6ppm信号处分裂成两个峰顶,88.7和83.1ppm,,表明C-4在热处理过程中发生了从纤维素Ⅰ~Ⅱ的化学转换,从化学结构变化的角度证明了碱处理可以有效破坏竹子纤维之间的内结合阻力,并产生高度活性纤维素,对于实现木质纤维素原料的高效生物转化利用提供指导。     

杉木无性系心材与边材微观结构特征快速检测

杉木(Cunninghamia lanceolata)是我国重要的速生针叶用材树种,其木材广泛应用于建筑、家具和船只等。杉木心材形成较早,心边材区别明显。快速检测新无性系心材和边材化学组分、细胞壁超微和显微构造等微观结构差异,可为了解该木材心材和边材品质性状提供重要的结构特征数据。以新培育的杉木无性系为实验材料,采用傅里叶变换红外光谱技术, X射线衍射技术,光学显微图像结合Image J图像分析技术,分别对杉木无性系洋61心材与边材的细胞壁化学组分、细胞壁纤维素结晶度及其显微构造进行了快速检测。研究结果表明,心材和边材红外光谱谱图中化学官能团的波数基本相同,即主要结构相同,其差别主要在峰强度上。心材的红外光谱谱图中酚类和醇类化合物特征峰(1 034和1 122 cm~(-1))及Caryl-O伸缩振动特征峰(1 264和1 232 cm~(-1))的吸收强度较边材的高,说明可能杉木无性系心材抽提物含量和木质素的交联程度高于边材。同时采用特征峰比值法分析了三大化学组分相对含量的变化,发现与边材相比,心材木质素相对含量增加2%～4%左右,纤维素相对含量减少约2%,半纤维素含量基本不变。通过分析X射线衍射图谱,发现杉木心材和边材的衍射图形状基本相同,不同的是边材的半高宽较心材的窄,且在2θ=22.5°处边材的峰强度高于心材,说明两者细胞壁纤维素结晶部分晶胞构造相同,但边材细胞壁纤维素结晶程度大于心材的。测算得知杉木心材相对结晶度为35.1%,边材相对结晶度为43.1%,两者在0.01水平具有显著差异。通过光学显微镜获得杉木心边材显微图像后,利用Image J图像分析技术快速检测到心材管胞腔面积比率和平均管胞面积均比边材的小,即心材细胞与边材相比具有壁厚腔小的特点。以上研究结果发现傅里叶红外光谱技术, X射线衍射技术和光学显微图像结合Image J图像分析技术可快速准确的检测杉木无性系心材和边材的微观结构特征差异。研究结果可为后续该无性系心材和边材的物理力学品质性状评价、细胞壁改性处理以及心材和边材的高效利用提供理论指导与科学依据。     

利用红外光谱评价文物微环境中有机酸对蚕丝纤维化学结构影响

研究文物微环境污染因素对文物材料影响是分析文物老化原因和妥善保存文物的重要基础。利用红外光谱(FTIR/ATR)剖析了文物微环境中甲酸、乙酸气体对蚕丝纤维结构影响。结果表明:低浓度甲酸气体能减弱纤维分子内氢键,使酰胺Ⅰ(1 617cm-1)谱峰减弱、酰胺Ⅱ谱峰(1 515cm-1)变窄、无规线团构象的酰胺Ⅲ谱峰(1 230cm-1)增强、纤维结晶度下降;当浓度高于8.1mg.m-3时,呈β-折叠构象的肽链段(GlyAla)n特征谱峰(1 000,975cm-1)增强、纤维结晶度提高。分析认为呈无规线团构象的短肽链发生β-折叠构象转变。乙酸气体对酰胺Ⅰ和酰胺Ⅱ谱峰影响不明显,但能引起无规线团构象增加和纤维结晶度降低,其作用弱于甲酸气体。本研究为进一步分析丝织品保存环境污染物的危害作用提供基础数据。     

中国古建筑石灰灰浆的光谱分析技术

石灰是中国古代最早使用的重要胶凝材料,广泛应用于房屋、墓葬、城墙、堤坝等古代建筑工程中。古人还在石灰灰浆中添加糯米浆、动物血液、植物汁液、红糖、桐油、纸筋、秸草等有机材料以增进其性能。此外,中国古代还使用石灰、粘土和砂石组成现在称为"三合土"的混合石灰材料以构筑墓葬、城墙和水利工程等建筑墙体。在古建筑遗址的修复和保护工作中,本着"修旧如旧"的原则,必须对古建筑修建所采用的原材料和施工工艺进行分析研究,从而为修复工作提供科学可靠的依据。本文综述了在对中国古代建筑石灰灰浆的分析中所采用的光谱分析技术,包括拉曼光谱、红外光谱、X射线衍射和X射线荧光光谱,以及扫描电子显微镜、热重分析等其它一些分析技术,讨论了各种分析技术的用途、优势和劣势。     

VO2热致变色薄膜的结构和光电特性研究

用磁控溅射方法制备了VO₂热致变色薄膜.用X射线衍射、X射线光电子谱和原子力显微镜对薄膜的宏观及微观结构进行了分析，表明VO₂薄膜纯度高、相结构单一、结晶度好.薄膜的光透过率在2000nm处相变前后改变了42%，高/低温电阻率变化达到三个数量级以上.薄膜的光透过谱和相变过程中电学性质变化的研究与结构分析结果相一致. 关键词：     

“钟离君柏”墓出土彩绘陶器颜料的光谱分析

利用拉曼光谱结合X射线衍射物相检测方法,对安徽蚌埠双墩春秋中晚期“钟离君柏”墓出土彩绘陶器颜料的物相结构进行了分析测定。结果表明,陶器表面的红色、黄色和黑色颜料皆保存较好,未发生明显变化,分别是无机矿物朱砂(HgS)和针铁矿(α-FeO(OH))及炭黑。同时,拉曼光谱与X射线衍射分析的结果都显示红色颜料朱砂的组成物相单一,不含天然朱砂的伴生矿物石英,且其晶粒尺寸可能在纳米范围,应是由人工合成或经过古人的加工、纯化处理。针铁矿的发现表明春秋时期该矿物己被用作黄色颜料,这是目前己知的针铁矿作为黄颜料使用的最早的实例。     

Synthesis and characterization of nano-sepiolite by solvothermal method

Nano-sepiolite with novel morphology has been fabricated by solvothermal method in different conditions. The nano-sepiolite was characterized by X-ray fluorescence analysis, X-ray powder diffraction, thermal gravimetry analysis, differential thermal analysis and infrared spectroscopy. Scanning electron microscopy observations revealed that using of solvothermal route led to nano-wires of sepiolite. The reactions have been performed in several conditions to find out the role of different factors such as the aging time and temperature of the reaction in the solvothermal on the size and morphology of the nano-structures.     

ICF靶用泡沫铜的制备与表征

 以次磷酸钠为还原剂的化学镀进行导电化处理,研究了ICF靶用泡沫铜的电沉积工艺。采用扫描电子显微境和X射线衍射仪对制备过程中各阶段泡沫铜的微观结构进行了表征。结果表明：经化学镀后可获得晶粒尺寸小、分布均匀的铜沉积层。电沉积后铜沉积层主要由0.55 μm的小颗粒组成,并且出现突出大颗粒的形貌特征。在氢气氛围下,经700 ℃热处理后,铜颗粒进一步长大,沉积层结晶致密。制备的泡沫铜呈3维网络状结构,分布均匀,密度为0.19 g/cm³,孔径分布为400～600 μm,孔隙率达97.9％。     

Simulation of X-ray diffraction patterns for silk fibres using paracrystalline statistics

Using paracrystalline statistics, we have simulated one-dimensional and three-dimensional X-ray diffraction patterns from natural silk fibres for various values of crystal size and lattice distortion parameters. This is in agreement with the experimental observation of X-ray pattern reported earlier.     

Ultrasound-assisted coating of silk yarn with sphere-like Mn3O4 nanoparticles

The growth of sphere-like trimanganese tetraoxide (Mn₃O₄) nanoparticles on silk fiber was achieved by sequential dipping in an alternating bath of potassium hydroxide and manganese(II) nitrate under ultrasound irradiation. Some parameters such as the effect of pH, numerous sequential dipping and ultrasonic irradiation on growth of the nanoparticles have been studied. The samples were characterized with powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and wavelength dispersive X-ray (WDX).     

Formation of silk fibroin nanoparticles in water-miscible organic solvent and their characterization

When Silk fibre derived from Bombyx mori, a native biopolymer, was dissolved in highly concentrated neutral salts such as CaCl₂, the regenerated liquid silk, a gradually degraded peptide mixture of silk fibroin, could be obtained. The silk fibroin nanoparticles were prepared rapidly from the liquid silk by using water-miscible protonic and polar aprotonic organic solvents. The nanoparticles are insoluble but well dispersed and stable in aqueous solution and are globular particles with a range of 35–125 nm in diameter by means of TEM, SEM, AFM and laser sizer. Over one half of the ɛ-amino groups exist around the protein nanoparticles by using a trinitrobenzenesulfonic acid (TNBS) method. Raman spectra shows the tyrosine residues on the surface of the globules are more exposed than those on native silk fibers. The crystalline polymorph and conformation transition of the silk nanoparticles from random-coil and α-helix form (Silk I) into anti-parallel β-sheet form (Silk II) are investigated in detail by using infrared, fluorescence and Raman spectroscopy, DSC, ¹³C CP-MAS NMR and electron diffraction. X-ray diffraction of the silk nanoparticles shows that the nanoparticles crystallinity is about four fifths of the native fiber. Our results indicate that the degraded peptide chains of the regenerated silk is gathered homogeneously or heterogeneously to form a looser globular structure in aqueous solution. When introduced into excessive organic solvent, the looser globules of the liquid silk are rapidly dispersed and simultaneously dehydrated internally and externally, resulting in the further chain–chain contact, arrangement of those hydrophobic domains inside the globules and final formation of crystalline silk nanoparticles with β-sheet configuration. The morphology and size of the nanoparticles are relative to the kinds, properties and even molecular structures of organic solvents, and more significantly to the looser globular substructure of the degraded silk fibroin in aqueous solution. It is possible that the silk protein nanoparticles are potentially useful in biomaterials such as cosmetics, anti-UV skincare products, industrial materials and surface improving materials, especially in enzyme/drug delivery system as vehicle.     

Formation of silver iodide nanoparticles on silk fiber by means of ultrasonic irradiation

The growth of silver iodide nanoparticles on silk fiber was achieved by sequential dipping in an alternating bath of potassium iodide and silver nitrate under ultrasound irradiation. Some parameters such as effect of pH, concentration and numerous sequential dipping in growth of the nanocrystal have been studied. The samples were characterized with powder X-ray diffraction (XRD), scanning electron microscopy (SEM), ICP, TGA and solid state UV–vis spectroscopy.     

Ultrasound-promoted coating of MOF-5 on silk fiber and study of adsorptive removal and recovery of hazardous anionic dye “congo red”

A metal–organic framework MOF-5 has been synthesized on silk fiber through electrostatic layer-by-layer assembly. The silk surface coating was formed via sequential dipping in an alternating bath of metal and ligand solutions at room temperature by direct mixing. SEM was used to investigate the growth of MOF-5 coating as materials for separation membrane due to their desirable properties in adsorptive removal of congo red (CR) from contaminated water. The adsorption capacity of MOF-5 is remarkable high in the liquid phase. The adsorption of CR at various concentration and contact time in spontaneous process were studied. The silk fibers containing MOF-5 open a wide field of possible applications, such as protection layers or membranes in pollution remediation wastewater and any effluent. Desorption of the dye can be carried out by using NaOH solution with more than about 50% recovery of congo red from MOF-5 coated on silk membrane filtration. In order to investigate the role of sonicating on the morphology of products, one of the reactions was performed with ultrasound irradiation and the crystal growth is completed more than other methods. The samples and adsorption of CR were characterized with SEM, powder X-ray diffraction (XRD) and UV–visible spectroscopy.     

The Mössbauer kinetics of the evolution of martensite during the ageing and first stage of tempering in high carbon steel

⁵⁷Fe Mössbauer spectroscopy is, with¹³C NMR, the only technique enabling to follow the redistribution of interstitials occuring during low temperature aging in ferrous martensite and responsible for the formation on the carbides obtained by tempering. We report the isochronal aging of martensite from as-quenched samples of high carbon content in order to follow the kinetics, all over the temperature range from 78°K to 400°K, thus covering the aging and the first stage of tempering as well. X-ray diffraction analysis is done in parallel for all temperatures above ambient. The results sustain the fact that one unique process is involved, leading to the precipitation of ∈ or ν carbide by stress-induced mechanism.     

Dense coating of surface mounted CuBTC Metal-Organic Framework nanostructures on silk fibers, prepared by layer-by-layer method under ultrasound irradiation with antibacterial activity

The growth of Cu₃(BTC)₂ (BTC = 1,3,5-benzenetricarboxylate), also known as CuBTC and HKUST-1, Metal-Organic Framework (MOF) nanostructures on silk fibers were achieved by layer-by-layer technique in alternating bath of Cu(OAc)₂·2H₂O and H₃BTC solutions under ultrasound irradiation. The effect of pH, reaction time, ultrasound irradiation and sequential dipping steps in growth of the CuBTC Metal-Organic Framework nanostructures has been studied. These systems depicted a decrease in the size accompanying a decrease in the sequential dipping steps. In addition, dense coating of silk fibers with CuBTC MOF results in decrease the emission intensity of silk fibers. The silk fibers containing CuBTC Metal-Organic Framework exhibited high antibacterial activity against Escherichia coli and Staphylococcus aureus. The samples were characterized with powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) spectra and scanning electron microscopy (SEM). XRD analyses indicated that the prepared CuBTC MOF nanostructures on silk fibers were crystalline.