Structure of decrystallized cotton in fabrics prepared by alkali and acrylonitrile treatments

The crystalline structure of decrystallized cotton, prepared by partial cyanoethylation with the use of sodium hydroxide aqueous solution and acrylonitrile, was examined by x-ray and IR data, in connection with such fabric properties as moisture regain. It was found that the moisture regain of the cotton fabric first increased, passed through a maximum at about 6 mole-% of cyanoethylation, and then slightly decreased with increasing degree of cyanoethylation. The increase of moisture regain in the region of the lower degree of cyanoethylation was well related to the decrease in the crystallinity of cotton. The x-ray diffraction studies revealed that the distension and disorder of the unit cell occurred primarily in the direction perpendicular to the (101) crystal plane as cyanoethylation proceeded.     

The morphological structures of net‐modified cotton cellulose with triazine derivative containing multireactive groups

Cotton fabric was chemically modified with a 1,3,5‐triazine derivative containing multireactive and multicationic groups, 2,4,6‐tri[(2‐hydroxy‐3‐trimethyl‐ammonium)propyl]‐1,3,5‐triazine chloride (Tri‐HTAC). The morphological structures of net‐modified cotton cellulose were investigated with differential scanning calorimetry, X‐ray diffraction, and scanning electron microscopy. The results showed that crystallinity and preferred orientation of net‐modified cellulose decreased. The tensile strength of net‐modified cotton decreased and crease recovery angle increased. The thermal stability of the net‐modified cotton was slightly improved. Representative scanning electron micrographs indicated that there appears to be appreciable difference in the appearance of the surfaces of the unmodified and the net‐modified cotton fibers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2700–2707, 2006     

Epitaxial crystallization of poly(butylene adipate) on highly oriented isotactic polypropylene thin film

The crystallization behaviors of PBA on highly oriented iPP substrate both from solution and isotropic melt were studied by means of optical microscopy, AFM, X-ray and electron diffractions. The results clearly indicate the occurrence of heteroepitaxy of PBA on the iPP substrate in its β-form with both molecular chains ±50° apart from. This is based on the existence of perfect matching between the interchain distance of β-PBA along [100] direction and the distance of the out-sticking methyl side group arrays along the [101] direction of the (010) iPP plane. Electron diffraction pattern further confirms that the (010) lattice plane of the β-PBA is in contact with the iPP substrate.     

Die dimensionen der kristallinen bereiche in fasern aus regeneratcellulose

The size of the crystalline regions of regenerated cellulosic fibers was determined by means of transmission electron microscopy, small angle X-ray scattering, and wide angle X-ray diffraction. All three methods lead in satisfying conformity to the following dimensions: length: 120–140 Å, width: 80–100 Å, thickness: 30–40 Å. The broad plane of the platelet shaped crystallites is situated parallel to the 101-lattice plane, the small edge plane has an orientation parallel to the 101-lattice plane. The -crystallites form strands, which have a length of 1500–5500 Å. They are partly bundled up to clusters with a diameter of 300–600 Å, partly separated by less dense spacings. The distance between the crystalline regions amounts to 20–40 Å in longitudinal and cross direction.     

Cellulose crystallite sizes in diploid and tetraploid native cotton

Cellulose crystallite sizes in directions perpendicular to (101), (101 ), and (002) planes, have been estimated from X-ray powder diffraction patterns. The diffraction peaks were resolved using the FIT X-ray diffraction data analysis program (written by SOCABIM, Siemens DIFFRAC AT Software System, Siemens, Germany). The complete data for all the three equatorial planes was analyzed for 2θ, d values, full width at half-maximum (FWHM), and the normalized area under the three diffraction peaks, for seven cotton cultivars grown at four different locations in India in different crop years. The mean crystallite sizes were determined using the Scherrer equation. The reference standard included degummed and purified ramie fibers for relative crystallinity estimation in cotton cultivars. It has been observed that, though the computed crystallite sizes corresponding to (101), (101 ), and (002) planes vary within individual varieties with location and year of growth, the combined average crystallite size corresponding to (101) and (101 ) planes taken together for individual varieties from all locations and crop years is close to the combined average crystallite size corresponding to the (002) planes, irrespective of the species of cotton. The values of the average relative crystallinity with respect to highly oriented degummed and purified ramie fibers of individual varieties from all locations and crop years do not significantly vary between varieties and species of cotton. It is visualized that variations in crystallite sizes arise as a result of the differences in the amount of cellulose synthesized within fibers of individual varieties and their disposition within the matrix of their developing fibers. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 2107–2112, 1998     

Heteroepitaxial growth and characterization of 3C-SiC films on on-axis Si (1 1 0) substrates by LPCVD

Cubic SiC (3C-SiC) film has been deposited on Si (1 1 0) substrate by the low pressure chemical vapor deposition (LPCVD) with gas sources of SiH₄, C₃H₈ and carrier gas of H₂. The 3C-SiC crystalline film can be confirmed through the observations using reflection high-energy electron diffraction (RHEED) images. The X-ray diffraction (XRD) pattern and the rocking curve indicate that the (1 1 1) plane of SiC film is parallel to the surface of the Si (1 1 0) substrate and the film is of high crystallinity. The results of the field emission scanning electron microscope (FESEM) images show that the film has smooth surface morphology. Transmitted electron diffraction (TED) pattern and high resolution transmission electron microscope (HRTEM) image further confirm the high quality of the film.     

Synthesis and characterization of Si/SiC ceramics prepared using cotton fabric

A Si/SiC ceramic was prepared from cotton fabric by the reactive infiltration of liquid silicon into the carbon template. A large density difference between the samples has been observed. This may be due to the variation in the pore size and its distribution within the sample. Scanning electron microscopy with energy dispersive spectroscopy shows the presence of three distinct phases, i.e., SiC, free Si and free carbon. X-ray diffraction pattern also confirms the presence of SiC and Si phases. However, there is no peak corresponding to carbon. So, it is inferred that the carbon exists in amorphous form. Micro-hardness, fracture toughness and bending strength of the ceramics were also studied. The values are lower than commercially available SiC ceramics. This may be due to the highly porous nature of cotton fabric-based SiC, as compared to commercially available SiC.     

负载织物对纳米TiO2光催化剂净化氨气性能的影响

制备了纳米光催化剂悬浮液,借助后整理工艺对3种织物进行负载加工,并利用X射线衍射仪(XRD)和扫描电镜(SEM)等对其进行了表征. 通过自行设计的小型环境舱和光催化反应器重点考察了棉机织物、涤纶机织物和涤/棉混纺机织物对纳米光催化剂净化氨气性能的影响,并比较了在不同负载织物表面上纳米光催化剂的活性. 结果表明,负载纳米光催化剂的棉织物的氨气净化性能高于负载纳米光催化剂的涤纶织物和涤/棉混纺织物的氨气净化性能. 在负载Ag-TiO2光催化剂的条件下,负载涤纶织物和涤/棉混纺织物对氨气的净化性能有所加强.     

Application of the optical transform to the electron diffraction pattern of polyethylene single crystal

The setting angle of the planar zigzag molecular chains in a polyethylene single crystal has been determined by optical transformation of the electron diffraction pattern, using the Patterson synthesis. The reproducibility of the original structure on optical transformation was confirmed by (1) the inverse optical transform of the optical diffraction pattern produced by a well defined two-dimensional model lattice and (2) the electron diffraction pattern calculated from the model crystal. The following points arising from the electron diffraction were examined: the dynamical scattering, multiple reflections and radiation damage of the specimen; the direction of the interatomic vector obtained by the present method of analysis and under these illumination conditions was found to be reliable. The optical results were confirmed by X-ray diffraction in which these effects were absent.     

Conductive Cotton Fabrics Coated with Myristic Acid/Zinc Oxide Nanoparticles

This research mainly deals with enhancement of electrical conductivity performance of cotton fabrics using zinc oxide nanoparticles. The application of nano-zinc oxide/myristic acid onto 100% cotton plain fabrics was performed by dipping process. The effect of myristic acid and zinc oxide nanoparticles on cotton fabrics was analyzed by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Electrical conductivity, UV protection performance, and hydrophilic properties of the cotton fabrics were also investigated. The surface resistivity of the cotton fabric noticeably dropped off by applying nano-zinc oxide/myristic acid. Furthermore, electrical conductivity of the coated cotton fabrics was maintained till 15 weeks. Surface hydrophilicity of cotton fabrics decreased with increasing myristic acid content. The changes in decomposition temperatures and crystallinity can be ignorable after application of myristic acid/nano-zinc oxide.     

阴离子对Mg(OH)2晶体生长及形貌的影响机理

以轻烧粉、氯化铵、硝酸铵、乙酸铵、硫酸铵为原料,氨气为沉淀剂,采用氨循环法制备氢氧化镁晶体,并通过扫描电镜（SEM）、X射线衍射（XRD）对其进行表征分析。采用Materials Studio分子模拟软件中的CASTEP模块,计算了Cl^-、NO₃^-、CH₃COO^-对氢氧化镁晶体（001）、（101）晶面生长的影响。结果表明,采用不同的镁盐得到不同形貌的氢氧化镁晶体阴离子电负性越大,对晶体形貌影响越小;Mg（OH）₂晶体的（001）、（101）晶面能量与布居数分析表明,Cl^-、NO₃^-、CH₃COO^-使晶体的（001）、（101）面的表面能增大、Fermi能级减小,阴离子与（001）、（101）晶面之间形成新的具有微弱共价性的离子键,影响晶体晶面的生长。理论计算较好地解释了不同形貌的氢氧化镁晶体的形成原因。     

New approach to antibacterial treatment of cotton fabric with silver nanoparticle–doped silica using sol–gel process

In this study, cotton fabric was successfully modified to have an antibacterial property through use of the sol–gel process. Dodecanethiol‐capped silver nanoparticles, which have powerful antibacterial activity, were incorporated in silica sol. The starting materials were silver nitrate, tetraoctylammonium bromide, sodium borohydride, chloroform, 1‐dodecanethiol, ethanol, tetraethylorthosilicate, and water. The cotton fabric was padded with dodecanethiol‐capped silver nanoparticle–doped sol, dried at 60°C, and cured at 150°C. Scanning electron microscopy showed a uniform and continuous layer of doped sol on the fiber surface. The antibacterial effects of the treated cotton fabric against Escherichia coli were examined and found to be excellent. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101:2938–2943, 2006     

Melt extrusion of polyethylene nanocomposites reinforced with nanofibrillated cellulose from cotton and wood sources

Replacing petroleum‐based materials with biodegradable materials that offer low environmental impact and safety risk is of increasing importance in sustainable materials processing. The objective of this study was to produce uniform nanofibrillated cotton from recycled waste cotton T‐shirts using microgrinding techniques and compare its performance as reinforcing agent in thermoplastic polymers constructs with wood‐originated materials. The effect of the microgrinding process on morphology, crystallinity, and thermal stability of materials was evaluated by transmission electron microscopy (TEM), scanning electron microscope (SEM), X‐ray diffraction (XRD), and thermogravimetry analysis (TGA). Nanofibrillated cotton resulted in higher crystallinity and thermal stability than fibrillated bleached and unbleached softwood. All the materials were extruded with low‐density polyethylene to fabricate nanocomposite films. Nanofibrillated cotton nanocomposites had a higher optical transparency than did the wood‐based composites. The mechanical properties of the nanofibrillated cotton nanocomposites were largely improved and showed 62.5% increase in strength over the wood‐based nanofibrillated containing composites, in agreement with the higher crystallinity of the nanosized cotton‐derived filler material. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41857.     

Mechanical and thermal properties of glycidyl methacrylate grafted cotton cellulose

UV-radiation-induced graft-copolymerization of cotton cellulose was carried out with glycidyl methacrylate (GMA) using ceric ammonium nitrate (CAN) as a photoinitiator as well as a chemical initiator. With increase in the graft add-on, breaking load and moisture regain of cotton decreased, so also its thermal stability. The fiber surface changes due to grafting were ascertained by X-ray diffraction and scanning electron microscopy. © 1995 John Wiley & Sons, Inc.     

Atomic-Scale {101¯0} Interfacial Structure in Hydroxyapatite Determined by High-Resolution Transmission Electron Microscopy

The atomic structure of {101¯0} interfaces in sintered hydroxyapatite (HAp) was characterized using high-resolution electron microscopy (HRTEM). When subjected to electron beam radiation parallel to the [0001] zone axis, a characteristic damage of HAp occurred. The damage was identified by hexagonally shaped regions surrounded with {101¯0} planes, in which the crystalline phase was thinned and amorphized. HRTEM study at the crystalline-amorphous interfaces revealed that the HAp crystal structure was terminated by a plane crossing the hydroxyl columns on which Ca (Ca2 site) and PO₄ tetrahedra were placed. The grain boundaries parallel to the {101¯0} planes were also examined and the structure was identical to that observed in the crystalline-amorphous interface. The interface structure observed in the crystalline-amorphous interfaces and grain boundaries is probably a stable atomic arrangement of HAp {101¯0} surfaces with a low surface energy.     

基于分形理论的陶瓷装饰图案设计方法的研究

本文介绍了基于分形理论进行陶瓷装饰图案设计 ,利用平面二维函数或规则的反复迭代生成复杂的分形集合的各种算法 ,该集合通过着色可以形成精美的图案 ,生成的图案可以输入到流行的设计软件以便对图案进一步加工。本文利用VB开发工具开发出基于分形理论的装饰图案设计系统 ,试用后的初步结果表明该方法应用到陶瓷装饰图案设计是可行的。     

Formation of nanocrystalline Zinc on ITO and Silicon substrates by electrochemical deposition

Zn was deposited by means of cyclic voltammetry (CV) and square wave pulsating overpotential (OP) methods on ITO (indium tin oxide) and n-doped silicon (n-Si) substrates from an acetate-based electrolyte at two different temperatures in the absence of additives. The surface morphology of the Zn deposits was studied by scanning electron microscopy (SEM). The preferred orientation and the average size of the Zn electrodeposited particles on n-Si substrates were obtained by X-ray diffraction and the microhardness of the deposits was measured by standard means. The results show that the grain size of the electrodeposits increases as the temperature rises, and on the other hand that the PO method yields smaller grains and higher hardness values compared with those obtained by CV, irrespective of the temperature. Furthermore, in PO conditions a preferential (101) orientation is obtained for the growth of the Zn electrodeposits, but for long deposition times the growth direction is that [100] corresponding to the basal plane (002).     

Structural study of cellophane

Fine structural aspects of cellophane have been investigated using X-ray and electron diffraction techniques as well as a kinetic study of the dissolution of cellophane in 0.5 M cupriethylene diamine solution. The X-ray diffraction pattern for cellophane shows a typical cellulose II structure while the electron diffraction pattern highlights a typical cellulose I structure with very weak reflection for a cellulose II type lattice. The kinetics study of cellophane dissolution in cupriethylene diamine confirms the presence of these polymorphic forms of cellulose in cellophane. The paper also reports studies of the X-ray and electron diffraction patterns of cellophane in relation to crystallite size and degradation under electron beam. It is shown that the observed anomaly between the X-ray and electron diffraction patterns of cellophane is a consequence of (i) the larger minimum crystallite size requirement for producing diffraction patterns with X-rays than with the electron beam (ii) the much faster degradation of cellulose II crystallites than that of cellulose I crystallites under the electron beam and (iii) the reduction in the crystallite size of cellulose II in cellophane from that in wood pulp alkali cellulose during the process of regeneration.     

Specific Features of Diffraction by Nanoparticles

The influence of the shape and size of nanoparticles on the scattered-intensity distribution in the reciprocal space, the shape of the spot in the electron diffraction pattern, and the X-ray diffraction line profile is investigated. It is demonstrated that the X-ray diffraction and electron diffraction data allow one to obtain valuable information on the structure of nanoparticles.     

铝元素对锌镀层耐蚀性的影响

研究了用复合电沉积法制备的锌铝镀层在微酸性腐蚀介质中的耐蚀性。试验结果证明,氢氧化铝也能改善镀层的耐蚀性,但不如铝粉的作用显著。EPMA和ICP显示含氢氧化铝和含铝粉镀层中的铝呈均匀分布状态,但前者铝的含量为50ppm,后者为0.15wt％。x-射线衍射法揭示溶液中的氢氧化铝能使镀层的结晶细致,晶面择优取向程度增加。当镀液中含有铝粉时,所得镀层的结晶晶面的择优程度更大,结构则成为层状的。因此,氢氧化铝和铝粉是通过提高镀层的晶面择优取向程度,从而改善了其耐蚀性能。