镧掺杂钡铁氧体-聚苯胺复合材料的制备与表征

采用溶胶凝胶法制备了镧掺杂钡铁氧体（BaLaxFe12-xO19,x=0、0.01、0.03、0.05）。通过XRD表征表明它们的结晶性良好,均为单一的磁铅石型钡铁氧体晶相结构,随镧掺杂量的增加,得到的镧掺杂钡铁氧体的粒径随之减小。采用溶液原位聚合法制备镧掺杂钡铁氧体-聚苯胺复合材料,红外光谱分析可知聚苯胺-铁氧体纳米复合物的生成,揭示了聚合物分子链与铁氧体纳米粒子之间存在一定的键合作用,TEM表征显示复合材料粒子呈球形,且粒径为60～80 nm左右。随着铁氧体含量的降低,样品的磁性能随之降低,即铁氧体含量是影响磁性能的主要因素。     

CM-CTS-PANI/Fe_3O_4磁性纳米材料的制备

在已有的无机/有机复合纳米粒子制备的基础上,以Fe(NO_3)_3·9H_2O和FeSO_4·7H_2O混合均匀作为母盐溶液,氨水溶液作为沉淀剂,在无需通氮气保护的空气条件下采用化学共沉淀法制备Fe_3O_4磁性粒子,将其制备成Massart磁性液体,熟化后通过原位聚合完成铁氧体-聚苯胺复合材料的制备,并用羧甲基壳聚糖掺杂,制备羧甲基壳聚糖掺杂聚苯氨基碳包覆磁性纳米材料。通过用SEM、红外对其进行了表征,该磁性纳米复合呈片状,平均粒径约15 nm。     

钡铁氧体-MCNT/PPY复合物的制备及性能研究

用溶胶凝胶法与自蔓延烧结法相结合制得钡铁氧体BaFe12O19,在碳纳米管(MCNT)中掺杂铁氧体获得具有一定吸波性能的磁性碳纳米管材料,并分别掺杂碳纳米管占吡咯单体百分含量的5%、10%、15%,通过电导率等测试研究不同吡咯单体含量对复合材料导电性的影响。最终得到的复合材料性能良好,电导率在10-8~103之间。     

稀土掺杂钴铁氧体的制备与性能研究

本文采用钴铁氧体最常用的溶胶法在添加稀土化合物的情况下制备稀土掺杂钴铁氧体。通过对制备的样品进行性能研究得如下结论:到稀土掺杂是改善钴铁氧体的有效手段,其生成的产物各项性能都有所改善,为钴铁氧体这中材料应用提供了更广阔的思路     

用废旧锂离子电池制备镍掺杂钴铁氧体

以废旧锂离子电池为原料,采用sol-gel法制备了镍掺杂的钴铁氧体。借助XRD、振动样品磁强计(VSM),就镍掺杂量对钴铁氧体结构和磁性能的影响进行了研究。结果表明:以酒石酸为凝胶剂,采用sol-gel法,用废旧锂离子电池可以制备出性能优良的尖晶石结构镍掺杂钴铁氧体;最佳的镍掺杂摩尔分数x(Ni2+)为0.2。     

可溶性纳米PANI-DBSA复合物光电性能研究

通过乳液聚合法制备纳米聚苯胺,使用十二烷基苯磺酸(DBSA)作为掺杂剂,在聚苯胺链上引入直链烷基,得到可溶性纳米聚苯胺(PANI-DBSA)复合物。研究了DBSA含量对PANI-DBSA复合物溶解度和电导率的影响,及制备过程中聚苯胺的生成和最终产物的紫外-可见光特征。结果表明:聚苯胺颗粒分散性好,粒径为20～100nm,当DBSA与苯胺单体摩尔比为3.0时,聚合物在甲苯中的溶解度最高为3.76%,当DBSA与苯胺单体摩尔比为1.0,聚合物导电性最好,电导率为250.4S/m。PANI-DBSA复合物在波长300～800nm具有良好的吸收性能。     

复合掺杂对高磁导率锰锌铁氧体磁性能的影响

用复合掺杂的方法制备了高性能的高磁导率MnZn铁氧体材料。研究了Nb2O5-P2O5复合掺杂对MnZn铁氧体微观结构及磁性能的影响。结果表明,适量的Nb2O5-P2O5复合掺杂有利于促进晶粒均匀致密,提高材料的起始磁导率,降低损耗。在配方中,当ζ(Nb2O5∶P2O5)为2∶8时,起始磁导率可达到11 823。     

Bi_2O_3对自燃烧法合成NiZnCu铁氧体的显微结构与性能的影响

以金属硝酸盐和柠檬酸为原料 ,应用溶胶 -凝胶法与自燃烧结合的方法制备了 Ni Zn Cu铁氧体微细粉。文章主要讨论了溶胶 -凝胶与自燃烧法结合制备 Ni Zn Cu铁氧体粉末的新方法 ,对 Bi2 O3掺杂的低温烧结 Ni Zn Cu铁氧体从烧结性质、结构与相组成、显微形貌、磁性质方面进行了研究 ,在此基础上分析了 Bi对材料形成过程和磁化机制的影响 ,并解释了掺杂量对材料磁性能的综合作用     

Bi2O3对自然烧法合成NiZnCu铁氧体的显微结构与性能的影响

以金属硝酸盐和柠檬酸为原料,应用溶胶－凝胶法与自燃烧结合的方法制备了NiZnCu铁氧体微细粉。文章主要讨论了溶胶－凝胶与自燃烧法结合制备NiZnCu铁氧体粉末的新方法,对Bi2O3掺杂的低温烧结NiZnCu铁氧体从烧结性质、结构与相组成、显微形貌、磁性质方面进行了研究,在此基础上分析了Bi对材料形成过程和磁化机制的影响,并解释了掺杂量对材料磁性能的综合作用。     

Bi_2O_3-Nb_2O_5复合掺杂对NiCuZn铁氧体性能的影响

运用Bi2O3-Nb2O5复合掺杂的陶瓷工艺,制备了NiCuZn铁氧体。从其微观结构出发,采用SEM分析手段,研究了Bi2O3-Nb2O5复合掺杂对NiCuZn铁氧体性能的影响。结果表明:适量的Bi2O3-Nb2O5复合掺杂,既有利于细化晶粒、促进晶粒均匀致密,又提高了品质因数Q,其磁性能明显优于单独掺杂。在掺杂总量的质量分数为0.5%、烧结温度为900℃、ζ(Bi2O3:Nb2O5)为7:3时,铁氧体的密度ρ为5.15g/cm3、起始磁导率μi为820.9、Q值可达110.5。     

退火参数对铁电TiN/HfxZr1-xO2/TiN薄膜器件的电学性能影响

采用磁控溅射法制备了Zr含量占比为0.134和0.156的TiN/HfxZr1-xO2/TiN结构的薄膜器件。对该器件进行了不同条件下的退火实验。研究了HfxZr1-xO2器件的电流、极化和循环特性,以及特性随退火温度和退火时间改变的变化规律,并结合微观结构表征手段,对器件特性随退火条件变化的规律做出了解释。在此基础上,总结出溅射法制备氧化铪锆薄膜的适用退火条件。实验结果表明,当退火温度低于氧化铪的居里温度时,退火后的器件仍表现出顺电性而不具有铁电性。Zr含量为0.156的HfxZr1-xO2器件在氧气中快速退火的最佳退火条件为:温度600℃、退火时间50 s。适当延长退火时间可以提高器件性能。     

Synthesis,characterization, and antimicrobial activity of chitosan–zinc oxide/polyaniline composites

Organic–inorganic materials of chitosan–zinc oxide/polyaniline (CS–ZnO/PANI) composite were prepared via precipitation with a polymerization method and characterized by FT-IR, XRD, EDXS and TEM analysis, thereby providing evidence of composite formation. The size of the prepared CS–ZnO/PANI composite was found to be 100–200 nm, thereby rendering the morphology suitable for biomedical applications. Antibacterial activities of chitosan–ZnO (CS–ZnO), polyaniline (PANI) and CS–ZnO/PANI composites were determined against Gram-positive bacterium, Staphylococcus aureus (S. aureus), and Gram-negative bacterium, Pseudomonas aeruginosa (P. aeruginosa) and were tested in-vitro at 5–50 μg/mL. Results showed that CS–ZnO/PANI composite had broad-spectrum antibacterial activity that was greatly enhanced in comparison with CS–ZnO. In addition, CS–ZnO/PANI composite has tested fungal strains of Candida albicans (C. albicans) and relatively higher activities were observed than the known antibiotics. Finally, the antimicrobial activity of CS–ZnO/PANI composite against established biofilms was also examined and resulted in more than 95% inhibition in biofilm formation.     

湿-干法合成超细颗粒PZT固溶体粉料及陶瓷

提出了一种制备PZT粉料及陶瓷的新工艺,即采用湿-干法制备PZT固溶体粉料。首先用聚合物中间体方法合成了钙钛矿型PZT中的B位离子氧化物固溶体ZrxTi1-xO2(x=0.50～0.56),并以此作为B位先驱体,其物相为单相,组成超出固相反应可以合成的单相ZrxTi1-xO2固溶体的锆钛比范围;然后用该先驱体与碳酸铅通过固相反应合成PZT固溶体。固相反应温度可显著降低至725℃,PZT粉料颗粒的粒度达到130nm。常温下,PZT陶瓷εr的最大值达到1260。     

聚苯胺金属纳米复合材料在电子元件中的应用

综述了聚苯胺与金属纳米所组成的复合材料在各种电子元件,如燃料电池、二次电池、超电容器、传感器和信息存储器件等方面的应用进展。针对该应用领域所存在的问题,提出了可能的解决方法和建议,最后指明了聚苯胺金属纳米复合物在电子元件应用中的发展方向。     

Acidified multi-wall carbon nanotubes/polyaniline composites with high negative permittivity

Acidified multi-wall carbon nanotubes (MWCNTs-COOH) have been synthesized using mixed acid acidification, and then acidified multi-wall carbon nanotubes (MWCNTs-COOH)/polyaniline (PANI) composites with negative permittivity have been successfully synthesized by in situ polymerization. At the same time, the effects of composition and structure on the permittivity of MWCNTs-COOH/PANI composites have been systematically studied. The effects of MWCNTs-COOH content on the generation and variation of negative permittivity are illuminated by the structure model of “nano wires”. XRD analysis indicates that MWCNTs-COOH becomes the crystal nucleus and affects the crystallinity of the MWCNTs-COOH/PANI composites. SEM results indicate that different contents of MWCNTs-COOH cause various dispersion states of MWCNTs-COOH, thus lead to different morphologies of MWCNTs-COOH/PANI composites and variation of permittivity.     

紫外发光的半导体MgxZn1-xO薄膜制备与性质

利用ZnO微晶粉末以化学电泳法成功地在导电玻璃上制备了不同x值的紫外发光的宽禁带氧化物半导体三元化合物MgxZn1-xO薄膜.电子显微镜和X 射线衍射研究显示,薄膜由MgxZn1-xO微晶组成,薄膜中微晶大小的分散度比ZnO粉末有所减小,并更具择优取向的趋势.室温下光致发光测量给出,MgxZn 1-xO薄膜在小于380nm的紫外波段出现较强的半宽小于20nm的激子性发光峰,而且带边峰的半宽以及带边峰与杂质缺陷峰强度之比均较原始的ZnO粉末有明显改善,表明这种MgxZn1-xO薄膜具有优良的紫外发光特性.     

Structural,Electrical, and Thermal Behavior of Graphite‐Polyaniline Composites with Increased Crystallinity

Conductive materials are at the forefront of materials science research because of the large number of applications that have been developed around their interesting and unique properties. This work reports for the first time a correlation between the structural, electrical, and thermal behavior of novel graphite‐polyaniline (G‐PANI) composites with electrical conductivities greater than either of the individual components. The G:PANI mass ratio was varied during synthesis of the composites (90:10, 95:5, 96:4, 97:3, and 98:2 G:PANI mass ratios) and the highest electrical conductivity was determined for the composite having a G:PANI mass ratio of 96:4. The structural changes related to this increase in electrical conductivity were clearly reflected by the Raman spectra of the new composites, which indicated an improved crystallinity through a better stacking along the c‐axis of graphite when PANI was present (as evidenced by the G and 2 × D modes at 1582 and 2684 cm⁻¹). X‐ray diffraction data showed a slight increase in the (0 0 2) graphite crystal plane distance that was associated with a dilute stage intercalation or a possible “pseudo‐intercalation” of the polymer species between the graphite layers facilitating charge transfer in the composites. It is proposed that polyaniline acts as a charge transfer component between basal planes of graphite. Thermogravimetric analyses of the samples showed similar trends for the thermal stability in accordance with the electrical conductivity, the Raman and X‐ray diffraction data. The potential impact of this work is evident in the many areas that utilize graphite as conductive filler in electrically conducting materials. The composites can be used for a large number of applications in nanoelectronics, electromagnetic interference shielding, rechargeable batteries or as other advanced nanocomposite materials with improved electrical, structural, and thermal properties.     

Thermoelectric Enhancement in Polyaniline Composites with Polypyrrole-Functionalized Multiwall Carbon Nanotubes

This work suggests a facile method to improve the thermoelectric properties of polyaniline (PANi) composites. Carbon multiwall nanotubes (MWNTs) were noncovalently functionalized with polypyrrole (PPy-MWNTs) based on in situ polymerization, and these PPy-MWNTs were used to synthesize PPy-MWNT/PANi composites. The surface-functionalized PPy nanolayer on the MWNTs was found to yield a homogeneous dispersion of MWNTs and strong interfacial adhesion. The resulting composites demonstrated a remarkable enhancement in both electrical conductivity and Seebeck coefficient, and exhibited a high power factor of 3.1 μW/m K² compared with the values of 0.006 μW/m K² for PANi and 0.1 μW/m K² for MWNT/PANi composite at 28.6 wt.% MWNT loading. The obtained results indicate that this method is useful for synthesizing conductive polymer composites with improved thermoelectric performance.