聚醚砜和磺化聚醚砜膜结构及性能研究

采用电镜和孔径分布测定仪对自制聚醚砜( PES)和磺化聚醚砜(SPES)膜进行表征,根据Darcy-Poiseuille定律研究PES膜和SPES膜过滤牛血清蛋白液(BSA)阻力分布情况.结果表明,PES膜孔径为0.22～0.27 μm,初始纯水通量为642 L·m-2·h-1,过滤质量浓度为1 g·L-1的BSA溶液时平衡通量为30.4～31.9 L·m-2· h-1; SPES膜孔径为5.2～11.1 nm,初始纯水通量为8.1 L·m-2·h-1,质量浓度为1 g·L-1的BSA时平衡通量为3.4～6.9 L· m-2·h-1.过滤时PES膜阻力主要集中在吸附和堵孔阻力,2者相加为总阻力的91.1％;而SPES膜阻力主要集中在膜本身的阻力,为总阻力的41.8％,其次为堵孔阻力,占总阻力的38.3％.经清洗后,PES膜的纯水通量可以恢复到82％,而SPES膜可以恢复到494％.     

磺化聚醚砜纳滤膜性能研究

本文主要研究了磺化聚醚砜 (SPES)复合纳滤膜的性能。详细讨论了纳滤膜对不同溶质的分离特性 ;探讨了无机盐浓度 ,操作压力 ,溶液 p H值及磺化聚醚砜的离子交换容量(IEC)与膜性能的关系 ;并对纳滤膜的电性能进行了初步研究。研究结果表明 ,磺化聚醚砜复合纳滤膜为一荷负电性纳滤膜 ,对无机盐有较好的选择分离性能。磺化聚醚砜的离子交换容量 ,无机盐浓度以及操作压力对膜性能影响较大 ,且对于两性溶质 ,膜的脱除性能与溶液 p H值有关     

磺化聚醚砜超滤膜的制备研究

本文研究了磺化聚醚砜的制备和膜性能的测试 ,通过选择适当的配方研制性能稳定的较小孔径的超滤膜。该膜在 0 .2Mpa操作压力下对聚乙二醇 1 0 0 0 0的截留率大于 95 % ,水通量为 5 5L/m2 H ,通过扫描电镜观察膜的断面结构 ,结果表明 :PES膜断面形态属于典型的非对称指状孔结构 ,SPES膜断面形态是海绵层结构     

磺化聚醚砜起滤膜的制备研究

本文研究了磺化聚醚砜的制备和膜性能的测试,通过选择适当的配方研制性能稳定的较小孔径的起滤膜。该膜在０．２Ｍｐａ操作压力下对聚乙二醇１００００的截留率大于９５％,水通量为５５Ｌ／ｍ＾２Ｈ,通过扫描电镜观察膜的断面结构,结果表明：ＰＥＳ膜断面形态属于典型的非对称指状孔结构,ＳＰＥＳ膜断面形态是海绵层结构。     

磺化聚醚砜(SPES)/聚醚砜(PES)合金超滤膜的研究

本文研究了磺化聚醚砜 (SPES) /聚醚砜 (PES)合金组份变化对膜性能的影响 ,通过选择适当的合金比例研制得到超滤膜 ,在 0 .2Mpa操作压力下 ,对聚乙二醇分子量为 1万的截留率大于 90 % ,水通量为 80L/m2 ·h ,对阴离子脱盐率PO3 -4 >SO2 -4 >CL-。通过扫描电镜观察膜的断面结构 ,结果表明 :PES膜断面形态属于典型的非对称指状孔结构 ,SPES/PES膜断面形态是致密的海绵状结构 ,致密层部分比SPES薄 ,SPES膜断面形态是较厚的海绵状结构 ,致密层部分多     

聚醚砜和磺化聚砜共混超滤膜的研究

本文主要叙述聚醚砜(PES)和磺化聚砜(S-PSF)共混之后膜性能的改善,得出共混膜要比单组分膜性能优良。并且,在加入致孔添加剂丙酮和聚乙二醇(PEG)后,膜性能得到进一步改善。     

磺化聚砜/聚醚砜纳滤膜的制备及性能表征

采用相转化法制备了磺化聚砜(SPSF)/聚醚砜(PES)共混新型纳滤膜,并研究了SPSF/PES共混质量比、水解的苯乙烯–马来酸酐共聚物(H–PSMA)的添加量、铸膜液预蒸发时间和温度对膜的脱盐率及水通量的影响。结果表明,当SPSF/PES共混质量比为4∶6,添加剂H–PSMA的质量分数为2%,铸膜液预蒸发时间为3 min,预蒸发温度为70℃时,在操作压力为0.5 MPa,料液温度为25℃下,SPSF/PES共混膜对2 g/L的Na_2SO_4盐溶液脱盐率为56.77%,水通量为24.45 L/(m~2·h)。     

磺化聚醚砜质子交换膜的制备及性能研究

以浓硫酸为溶剂、氯磺酸为磺化剂对聚醚砜（PES）进行了磺化，采用氢核磁共振谱（^1H NMR）、傅立叶变换红外光谱（FTIR）及热重分析（TGA）对磺化聚醚砜（SPES）进行了表征，证实PES得到了磺化。制备了一系列不同磺化度的SPES膜，测试了膜的接触角、含水率和电导率。试验结果表明，SPES具有良好的热稳定性；随着磺化度的增加，膜的亲水性能增加，膜的电导率增加。当SPES膜的磺化度达到37．0％（摩尔分数）时，SPES膜在室温下的电导率与商业化的Nafion 112膜的电导率相当。     

十八烷/PSt相变微胶囊的制备及其热性能研究

细乳液法制备了十八烷/聚苯乙烯(PSt)相变微胶囊,用TEM、DLS和DSC等对微胶囊进行了表征。研究了十二烷基硫酸钠(SDS)的加入量、亲水性单体丙烯酸的加入量、引发剂类型以及苯乙烯与十八烷的加料比对产物形态的影响。研究表明:低的SDS浓度有利于微胶囊结构的形成,产物粒子的平均粒径随SDS加入量的增大而减小;加入亲水性共聚单体丙烯酸可以改善微胶囊的形态,但产物中PSt均相微球增多;使用油溶性引发剂AIBN比使用KPS更加有利于微胶囊的形成;苯乙烯与十八烷的投料比为1∶1时,制备的微胶囊相变焓为111.6 J/g。     

Effect of the addition of poly(d-lactic acid) on the thermal property of poly(l-lactic acid)

Thermal property and crystallization behavior of PLLA blended with a small amount of PDLA (1-5 wt%) were studied. PDLA molecules added in PLLA formed stereocomplex crystallites in the PLLA matrix. When the blend was cooled to a temperature below T_m of PLLA, stereocomplex crystallites acted as nucleation sites of PLLA and enhanced the crystallization of PLLA significantly (heterogeneous nucleation). Such crystallization enhancement was not observed when the blend with lower PDLA content was cooled from 240 °C at which both PLLA crystal and the stereocomplex disappeared. Low molecular weight PDLA isolated in the matrix of PLLA did not form a stereocomplex crystallite with a large surface area enough to act as a nucleation site. On the other hand, high molecular weight PDLA chains formed a large stereocomplex crystallite. With increasing PDLA content, stereocomplex crystallites were more easily formed and they acted as nucleation sites. PLLA crystal near the stereocomplex crystallites has an incomplete structure and showed a melting peak at a lower temperature than pure PLLA crystal.     

添加剂对锆质定径水口烧结性能和抗热震性的影响

采用粉末成型工艺,以粒度为0.045mm的斜锆石粉和粒度均为0.154mm和0.074mm的MgO部分稳定电熔氧化锆和CaO部分稳定电熔氧化锆为原料,分别加入不同添加剂Y2O3、CeO2和Y2O3 CeO2,在300MPa的压力下成型,并于1720℃烧后制成锆质定径水口试样。结果表明通过合理控制颗粒级配和优化工艺参数,当添加剂中Y2O3和CeO2的含量(w)分别为0.6%和0.4%时,氧化锆的稳定率约为70%,同时可得到显气孔率低,体积密度高,抗热震次数≥5次的锆质定径水口。     

焦煤中配入钢渣对焦炭热性能的影响

在焦煤中添加不同比例的钢渣进行炼焦,考察所得焦炭的热性能。焦炭反应性随着钢渣添加量增加逐渐增大,但存在一个饱和点,而焦炭反应后强度持续降低。比表面积和SEM研究显示反应性过大,焦炭的微孔扩大而相互贯通导致比表面积减小和反应后强度降低。钢渣颗粒在焦炭中均匀分布。     

稠油比热容导热系数及粘温物性参数变化研究

利用Anton Paar MCR301旋转流变仪开展了不同区块稠油粘温性的实验研究,在20～300℃,利用HA-Ⅱ型比热容测定装置及HA-Ⅱ型导热测定装置,测定了岩石、水和不同区块稠油的比热容及不同区块稠油的导热系数.研究结果表明,稠油的粘度对温度非常敏感,随温度升高而大幅度降低.在20～300℃,稠油的比热容值在1.6840～4.4939 J/(g·K)变化,变化范围较大.稠油的导热系数都有随着温度的升高而降低的规律,并且在数值上较为接近,在20～300℃,导热系数在0.1196～0.1650W/(m·K)变化,变化范围很小.     

Research progress on hafnium-based thermal barrier coatings materials

Thermal barrier coatings (TBC) are important materials applied to hot part components of aero-engines in order to improve their service temperature. Increasing inlet temperature is an important factor to achieve elevated thrust-to-weight ratio and high heat engine efficiency. In recent years, traditional TBC materials have gradually reached their operating limits due to the increase in turbine operating temperature. Hafnium-based materials become promising new candidates for TBC because of the similar structure, higher temperature phase stability and lower thermal conductivity compared to traditional zirconium-based materials. In this review, recent progresses in the research and development for hafnium-based TBC materials are summarized. The phase stability, thermal and mechanical properties of rare-earth (RE)-doped HfO₂ and RE hafnate materials are introduced. RE-doped HfO₂ has good thermal properties and phase stability at high temperatures whereas relatively low fracture toughness. The RE hafnates possess the advantages of a higher phase transition temperature, lower thermal conductivity and superior fracture toughness than RE zirconates. However, the thermal expansion coefficients of most RE hafnates are quite different from the alloy matrix. Finally, further research directions for hafnium-based TBC materials are prospected in this study.     

MAX phase Zr2SeC and its thermal conduction behavior

The elemental diversity is crucial to screen out ternary MAX phases with outstanding properties via tuning of bonding types and strength between constitutive atoms. As a matter of fact, the interactions between M and A atoms largely determine the physical and chemical properties of MAX phases. Herein, Se element was experimentally realized to occupy the A site of a MAX phase, Zr₂SeC, becoming a new member within this nanolaminated ternary carbide family. Comprehensive characterizations including Rietveld refinement of X-ray Diffraction and atom-resolved transmission electron microscopy techniques were employed to validate this novel MAX phase. The distinct thermal conduction behaviors emerged are attributed to the characteristic interactions between Zr and Se atoms.     

Towards thermal barrier coating application for rare earth silicates RE2SiO5 (RE= La,Nd, Sm,Eu, and Gd)

Rare earth (RE) silicates X1-RE₂SiO₅ (RE = La, Nd, Sm, Eu, and Gd) are comprehensively investigated as promising thermal barrier coating candidates. The mechanical, thermal, and corrosion resistance properties are evaluated by theoretical exploration and experimental measurement. Mechanical properties and corrosion resistance to calcium-magnesium alumino-silicates (CMAS) melts of X1-RE₂SiO₅ are linearly correlated with ionic radius of RE elements. Elastic moduli increase with the decrease of ionic radius of RE³⁺. X1-RE₂SiO₅ with larger RE³⁺ exhibits better resistance to molten melts corrosion. For thermal properties, they are not obviously sensitive to RE species. All X1-RE₂SiO₅ demonstrate low thermal conductivities and their magnitudes are significantly modified by concentration of defects. Thermal expansion coefficients of X1-RE₂SiO₅ are more or less close and are compatible with the value of superalloy. The results highlight X1-RE₂SiO₅ as potential thermal barrier coating candidates with overall properties.     

耐火材料物性参数对脱硫喷枪热应力的影响

应用有限元法对某混铁车铁水脱硫喷枪的工 作温度场与应力场进行了动态仿真,分析了喷枪用耐 火材料物性参数(热导率、热膨胀系数和弹性模量)对 喷枪最大热应力的影响。结果表明:喷枪的最大热应 力与喷枪耐火材料的热导率呈对数函数关系,即当热 导率较小(<2W·(m·K)-1)时,其对最大热应力的 影响较大;当热导率较大时,对最大热应力的影响变 小。喷枪的最大热应力随喷枪耐火材料的热膨胀系数 变化的规律为一条高次曲线,热膨胀系数约为1.0× 10-5K-1时,最大热应力的值最小;喷枪的最大热应力 随耐火材料的弹性模量的提高而线性增大。     

PET-PCT共聚酯的制备及其热性能研究

由直接酯化法制备了不同1,4-环己烷二甲醇(CHDM)含量的聚对苯二甲酸乙二醇酯-聚对苯二甲酸-1,4-环己烷二甲醇酯(PET-PCT)共聚酯;利用核磁共振表征了合成产物的实际组成及序列结构;采用差示扫描量热和热失重分析研究了共聚酯的结晶特性和热稳定性。结果表明:合成的共聚酯为无规嵌段聚合物,PCT的实际组成均高于投料比,各链段的序列长度与其含量成正比。随着CHDM含量的增加,共聚酯的玻璃化转变温度升高,退火后的试样在低温处和高温处出现了两个熔点,且熔点和焓值随PCT含量的增加而降低。合成产物热稳定性优良,起始分解温度均大于400℃,最大分解温度大于435℃。用Friedman法对热分解动力学的分析,进一步证明共聚酯的热稳定性优良。