Cementation of Loose Sand Particles based on Bio-cement

Loose sand particles could be cemented to sandstone by bio-cement(microbial induced magnesium carbonate). The bio-sandstone was firstly prepared, and then the compressive strength and the porosity of the sandstone cemented by microbial induced magnesium carbonate were tested to characterize the cementation effectiveness. In addition, the formed mineral composition and the microstructure of bio-sandstone were analyzed by X-ray diffraction(XRD) and scanning electron microscopy(SEM), respectively. The experimental results show that the feasibility of binding loose sand particles using microbial induced magnesium carbonate precipitation is available and the acquired compressive strength of bio-sandstone can be excellent at certain ages. Moreover, the compressive strength and the porosity could be improved with the increase of microbial induced magnesium carbonate content. XRD results indicate that the morphology of magnesium carbonate induced by microbe appears as needles and SEM results show that the cementation of loose sand particles to sandstone mainly relies on the microbial induced formation of magnesium carbonate precipitation around individual particles and at particle-particle contacts.     

Morphology of Barium Hydrogen Phosphate Formation Induced by Phosphate-Mineralization Microbe

Phosphate-mineralization microbe was chosen to study the influences of bacterial mixture,filtrate,bacteria solution,bacterial body and bacterial secretion on barium hydrogen phosphate crystal formation.The chemical compositions and structures of samples were characterized with scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray diffraction techniques(XRD),revealing that the crystal morphology of barium hydrogen phosphate was dumbbell-shaped pattern,nanoparticles via aggregate clusters,irregular sphere with different sizes.The results indicated that bacterial body and bacterial secretion could induce the formation of irregular quadrilateral and spheres,respectively.But the effect of bacterial secretion was stronger than that of bacterial body when induced barium hydrogen phosphate crystal in bacteria solution.However,the crystals form could be affected only in bacterial mixture,but filtrate could induce the formation of nanoparticles.As a result,the bacteria and metabolites play an important role in the process of crystal nucleation,growth,and accumulation of barium hydrogen phosphate.     

Mineralization and Cementation of Fugitive Dust based on the Utilization of Carbon Dioxide and Its Characterization

Fugitive dust was cemented, forming larger particles bond in the calcite-consolidation-layer by microbial method. The particular composition, the morphology, and thermal decomposition properties of the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and differential scanning calorimetry-thermogravimetry (DSC-TG). The characterization data obtained showed that loose fugitive dust particles could be bonded and formed the consolidation-layer under the effect of calcite obtained by microbial method successfully. Meanwhile, the sample obtained by microbial method had superior wind-erosion resistance.     

湿化学法制备ATO/TiO2导电复合粉体包覆机制的研究

采用湿化学共沉淀法,通过在TiO2颗粒表面包覆Sb掺杂SnO2（ATO）制备ATO/TiO2导电粉.运用TG-DSC、XRD、XPS、SEM、BET和电导率等手段对ATO/TiO2导电粉进行了表征.研究结果表明：锡锑混合物xSn（Sb）O2·yH2O以非晶态的形态靠范德华力与静电引力吸附在TiO2表面,煅烧过程中,xSn（Sb）O2·yH2O脱去结晶水吸附或鍵合在TiO2表面.随着TiO2颗粒表面包覆层ATO厚度逐渐增加,ATO/TiO2粉体的电导率逐渐增加.     

竹纤维碱化改性对竹纤维/聚丙烯复合材料性能的影响

用不同浓度的NaOH 溶液对竹纤维(bamboo fiber, BF) 进行表面改性处理, 一定温度烘干后, 通过熔融挤出 制备了竹纤维/聚丙烯(BF/PP) 竹塑复合材料。采用示差同步扫描热分析仪(TG-DSC)、红外光谱(FTIR)、X 射线衍 射仪(XRD) 和扫描电镜(SEM) 等对预处理前后BF 的结构进行表征, 并研究了复合材料的力学性能。结果表明: 改 性后BF 的热稳定性升高, 形成疏松的纤维束; 复合材料的力学性能显著提高。其中用3% 的NaOH 溶液改性BF 制 备的复合材料的力学性能最佳, 冲击强度较纯PP 可提高100%, 屈服强度提高14.8%。复合材料冲击断面SEM 显 示, 一定浓度的NaOH 溶液改性可以明显提高BF 与PP 基体树脂间的相容性。     

Structure and Properties of BaFe12O19 Coated Fly Ash Cenospheres by Sol-Gel Process

1 IntroductionFly ash cenospheres are generated in large amountsas a by-product in thermal power plants and pose majordisposal problems . Fly ash cenosphere particles areunique, property stable , non-toxic , non-metallic hollowmicro-particles . Due to the unique hollowstructure andphysical mechanics properties ,fly ash cenosphere parti-cles have been dispersed in different matrices ,such aspolyester resins ,cement ,and nickel for producing com-posite materialsinthe bulkand coatingformsfor a va…     

预辐照PE接枝PS的制备及性能表征

将聚乙烯（PE）进行预辐照,采用悬浮接枝聚苯乙烯（PS）制备聚乙烯接枝聚苯乙烯（PE-g-PS）。利用红外光谱（FTIR）、核磁共振氢谱（1H-NMR）、X射线光电子能谱（XPS）、扫描电子显微镜（SEM）、差热扫描量热仪（DSC）、击穿场强及流变测试等对PE-g-PS的结构及性能进行表征。结果表明：PE-g-PS的FTIR谱图在1602cm-1,3026cm-1,和3060cm-1处出现明显吸收峰;PE-g-PS的1H-NMR谱图在化学位移为6.5~7.0ppm之间出现了新峰,这是苯环上H的化学位移;证明PS与PE接枝成功。与PE相比,PE-g-PS的结晶温度升高4oC,复合粘度降低,击穿场强提高4.6kv/mm。     

微细粒弱磁性铁矿的选择性絮凝机理研究

应用紫外—可见光分光光度计和红外光谱仪等测试手段,较为详细地研究了菱铁矿、褐铁矿和镜铁矿的选择性絮凝作用机理。结果表明,在高pH值的条件下,阴离子聚丙烯酰胺主要靠氢键和化学键的作用吸附在氧化铁矿表面,是以化学吸附为主的单分子层吸附,桥联模式为矿粒/聚合物—矿粒;在有高模数水玻璃M_(3-1)存在的条件下,阴离子聚丙烯酰胺与铁矿物表面的作用机理不同于与石英表面的作用机理。     

MPECVD法在抛光石英玻璃上沉积金刚石薄膜

采用微波等离子体增强化学气相沉积方法(MPECVD),利用氢气和甲烷混合气体,在抛光石英基片上低温沉积出金刚石薄膜。用扫描电子显微镜(SEM)、激光拉曼光谱仪(Raman)和傅立叶红外光谱仪(FTIR)对薄膜的表面形貌、颗粒尺寸、纯度和光学透过性能进行了表征。通过SEM发现,得到的金刚石薄膜的颗粒尺寸为0.2~0.3μm,形核密度超过109cm-2,从薄膜形貌可以发现,较高温度有利于提高薄膜的生长速率和颗粒尺寸的均匀性。通过拉曼光谱和红外透射光谱分析发现,较高温度下沉积的薄膜具有较高的金刚石相含量,薄膜的光学透过性能也相对较好。     

氮化钛纳米粒子的制备及表征

以金属钛为原料 ,采用氢等离子体金属反应法制备了纳米TiN颗粒。通过X射线衍射 (XRD) ,透射电镜 (TEM ) ,扫描电镜 (SEM ) ,X射线能谱 (EDS) ,热重 差热分析(TG DSC)等手段对粒子的成分、形貌 ,相结构 ,热性能等进行了表征。实验结果表明 :在氮气氛下 ,采用等离子体金属反应法可制备氮化钛纳米粒子 ,粒子粒径均匀 ,形状均为立方体 ,纯度高 ,分散性好 ,热稳定性好     

锐钛矿型TiO2多孔薄膜的室温制备及其机理研究

为在低温条件下制备多孔性TiO2薄膜,采用具有锐钛矿晶粒的TiO2溶胶与苯丙乳液混合制得涂膜液,通过浸渍提拉法制备薄膜,利用甲苯选择性地将薄膜中的苯丙乳液粒子溶解去除,制备出锐钛矿型TiO2多孔薄膜.使用扫描电镜(SEM)、透射电镜(TEM)、傅里叶变换红外光谱(FTIR)以及Zeta电位等分析测试方法对其制备机理进行了探讨.结果表明,TiO2溶胶与苯丙乳液混合后,陈化时间的延长有利于TiO2胶粒通过静电、氢键作用在苯丙乳液粒子表面形成吸附层,从而改变涂膜液的成膜性,形成较为密集、且均匀分布的岛状多孔结构,在此基础上经两次涂膜,即可获得具有致密孔洞的TiO2多孔薄膜     

Preparation and Characterization of Lignosulfonate Intercalated Layered Double Hydroxides and Their Application in Improving Ultraviolet Aging Resistance for Bitumen

In order to develop economically anti-ultraviolet(UV) aging additives to bitumen and extend the comprehensive utilization of lignin materials, lignosulfonate(LS) was selected to intercalate into layered double hydroxides(LDHs), then the LS intercalated LDHs(LS-LDHs) were applied to improve UV aging resistance of bitumen. With the characterization of X-ray diffraction(XRD), Fourier transform infrared(FTIR) spectroscopy, chemical analysis and scanning electron microscopy(SEM), LS was successfully intercalated into the galleries of LDHs. The ultraviolet and visible(UV-vis) absorbance curves showed LS-LDHs had excellent UV absorptive ability from 200 to 400 nm. Thermogravimetry and differential scanning calorimetry(TG-DSC) indicated LS-LDHs could have a good thermal stability during the processing of bitumen. Compared with the LDHs, the LS-LDHs exhibited better performance in UV aging resistance of bitumen.     

高温对粉煤灰表面解聚作用研究

通过硅铝质胶凝材料高温增钙改性的优化方法,应用电子显微镜(SEM)、核磁共振(NMR)、傅里叶红外光谱(FTIR)等测试手段研究了改性粉煤灰硅铝网络结构的解聚机理与规律.结果表明:高温增钙使粉煤灰表面部分Si-O键断裂,导致高配位的网络中间体Al及Ca较多渗入,网络结构部分强峰的化学位移向低场移动,网络结构聚合度降低,化学活性明显提高.最终优化的高温增钙粉煤灰配比为CFA-4-1 200℃,即81.0%LCFA1+15.0%CaO+3.0%石膏+1.0%萤石,温度制度为1 200℃下0.5 h.     

Ag/TiO2纳米粒子的制备与表征

为了扩大纳米TiO_2在可见光范围的吸收,进行在纳米TiO_2中掺入Ag实验.以工业级偏钛酸、硝酸银为主要实验原料,采用一种简易的方法制备出Ag/TiO_2纳米粒子,并通过X线衍射(XRD)、扫描电子显微镜(SEM)、透射电镜(TEM)、X射线光电子能谱(XPS)、紫外一可见光吸收光谱(UV-vis)对该粒子进行表征.结果表明,二氧化钛以锐钛型晶型,银以单质的形式存在于纳米复合粒子中;Ag的结合能367.476 eV(3d_(3/2))与373.453 eV(3d_(5/2))分别比纯银的结合能368.4 eV(3d_(3/2))与374.4 eV(3d_(5/2))低,这是由于制备Ag/TiO_2时煅烧温度较纯银高,银簇生长较大引起的;并显示复合粒子的粒径约为30 nm;Ag/TiO_2纳米粒子感应波长明显红移,增强了纳米TiO_2在可见光范围内的吸收.     

生蚝壳作为微生物固化砂土钙源的试验研究

微生物诱导碳酸钙沉淀（microbial induced calcium carbonate precipitation,MICP）是一种新兴的环保地基加固技术,使用该技术需消耗大量化学分析级试剂,如尿素、钙盐等,对环境等造成一定的不良影响。基于利用废弃资源的理念,选取厨余垃圾生蚝壳作为MICP固化砂土钙源,并与用硝酸钙、氯化钙作为钙源进行对比。通过无侧限抗压强度试验、渗透试验、碳酸钙质量分数测试、干密度试验和扫描电镜试验（SEM）等探讨该方法的可行性。试验结果表明,以生蚝壳为钙源的MICP固化砂柱的平均孔径最大,但其表观孔隙率最低,无侧限抗压强度、渗透系数、碳酸钙质量分数、干密度等物理力学指标均优于化学钙。SEM试验结果显示,不同钙源固化砂柱砂颗粒表面均有碳酸钙沉淀生成,生蚝壳钙源获得的碳酸钙沉淀晶体形态是表面比较粗糙,伴有微小孔隙的球体形态;硝酸钙获得的碳酸钙沉淀是介于球状和棱柱体之间的多棱角的簇状;氯化钙获得的碳酸钙沉淀呈现颗粒相互交错堆积的簇状。     

煅烧温度对ATO/TiO_2粉体表面晶化及电导率的影响

用湿化学法在TiO2颗粒表面包覆ATO制得ATO/TiO2复合导电粉;运用TG-DSC、XRD、XPS、SEM、和电导率测试等手段对ATO/TiO2导电粉进行了表征.结果表明：煅烧温度对SnO2的晶化程度、Sb的价态、ATO/TiO2导电粉的导电性产生影响.电导率-温度（lnσ-T）关系呈抛物线（100～900℃）：上坡段（150～400℃）,温度增加,无定形SnO2逐渐晶化,电导率增加,导电性上升,溶入SnO2的Sb3＋→Sb5＋转变,载流子浓度加大,包膜层多孔结构逐渐致密化;底部平台（400～600℃）,SnO2晶化结束,Sb3＋→Sb5＋转变趋于完成,电子散射趋于最低,电导率最大,导电性达到最佳;下坡段（600～900℃）,Sb3＋→Sb5＋转变发生逆转,TiO2基体颗粒长大,锐态型向金红石型转变,破坏包膜结构,电导率上升,导电性恶化.     

Influence of heat treatment temperature on microstructure and bonding of TiO<Subscript>2</Subscript> film coated on diamond particles surface

TiO₂ films were coated on the surface of diamond particles using a sol-gel method. The effects of heat treatment temperature on the morphology, phase composition and chemical bond of diamond particles coated with TiO₂ films were investigated through SEM, TEM, X-ray diffraction analysis, Raman spectroscopy, FTIR, and XPS. The results showed that when being heat-treated at 600 °C, the amorphous TiO₂ film transfered to the anatase film which bonded well with diamond substrate. Meanwhile, the Ti-O-C bond formed between TiO₂ film and diamond substrate. When being heat-treated at 800 °C, TiO₂ film was still anatase, and partial diamond began to graphitize. The graphitizated carbon could also form the Ti-O-C bond with TiO₂ film, although TiO₂ film would tend to crack in this case.     

无皂乳液聚合制备PMMA／MMT纳米复合材料的研究

采用离子交换法,用溴化烯丙基三乙基铵对钠基蒙脱土进行改性制备了有机蒙脱土,再以甲基丙烯酸甲酯（MMA）为单体,过硫酸钾为引发剂,通过无皂乳液聚合制备聚甲基丙烯酸甲酯朦脱土（PMM-MMT）纳米复合材料。采用傅里叶变换红外（FTIR）、X-射线衍射（XRD）和扫描电镜（SEM）等手段对有机蒙脱土和复合材料的结构进行表征。结果表明：溴化烯丙基三乙基铵成功插层到蒙脱土层间,层间距由1．32nm增大到1．44nm;FTIR和XRD测试结果表明不同蒙脱土含量的PMMA/MMT纳米复合材料均具有剥离型结构;SEM测试结果表明PMMA/MMT纳米复合粒子的粒径随蒙脱土含量的增加而减小。     

Clogging behavior of submerged entry nozzles for Ti-bearing IF steel

The nozzle clogging behavior of Ti-bearing IF steel was studied by metallographic analysis,scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS),and X-ray diffraction(XRD).According to the experimental results,nozzle clogging primarily appears three layers.There are a lot of large-sized iron particles in the inner layer and mainly slag phase in the middle and outer layers.The principal clog constituents of the inner layer are loose alumina cluster inclusions and granular shaped alumina i...     

氢等离子体处理金刚石成核面

通过用氢等离子体对微波等离子体化学气象沉积法在钼基体上制备的金刚石厚膜的成核面进行表面处理,并利用拉曼光谱、扫描电镜和X射线光电子能谱对处理前后金刚石成核面进行表征,比较了处理前后金刚石成核面金刚石相含量、表面粗糙组度,并分析了薄膜中钼原子的化合态及百分含量.结果表明:经过氢等离子体处理后的金刚石成核面的金刚石相含量提高,表面粗糙度增大,钼原子的百分含量由1.64%变为0.83%,且能有效还原成核面上钼的氧化物生成碳化钼和碳化二钼.