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1.
采用低温等离子体聚合改性技术在医用钛表面聚合丙烯胺单体,沉积一层聚合物改性层,在此过程中,以氮等离子体注入作为预处理,研究等离子体预处理对表面丙烯胺聚合改性层的性能影响。采用扫描电子显微镜、原子力显微镜、以及能谱分析、傅里叶红外光谱分析仪对不同条件下等离子体聚合物表面改性层的形貌、拓扑结构、官能团结构及化学成分进行研究,以及通过表面接触角测试仪分析表面亲水性能。结果显示,低温表面等离子体聚合手段能够在钛合金表面形成一层厚度可以调节的纳米聚合物改性层,电化学测试表明,聚合物改性层能够提高表面耐腐蚀性能;接触角测试表明表面聚合物改性层能够提高钛合金表面的亲水性能;FTIR分析表明低温表面等离子体聚合手段能够很好的保留丙烯胺中的氨基官能团,因此能够改善聚合物层的生物活性,有利于细胞的生长。同时,氮的注入之所以能够提高丙烯胺表面聚合物层与基体的结合效率,是因为氮等离子体注入预处理能够在钛合金表面形成梯度结构的过度TiN层,能够有利于等离子聚合过程中–C–N、C–H、–C–NH2、–O=C–NH2等官能团与基体之间的键合。  相似文献   

2.
通过等离子体引发聚合的方法,使三氟氯乙烯(CTFE)在CPP(流延聚丙烯)薄膜表面发生聚合反应.分别对未处理的CPP薄膜和经等离子体聚合处理的CPP薄膜进行质量分析、扫描电镜和能谱表征,证实在CPP薄膜表面生成了含氟聚合物.在一定范围内考察了聚合时间、板极电压和压力对三氟氯乙烯沉积速率的影响,由于等离子体刻蚀作用与聚合反应同时存在,沉积速率与3种过程因素均未呈现线性关系.氟聚合物层使薄膜表面极性减弱,导致表面能中极性分量所占的比例减少,色散分量的比例增加,表面能降低,水和乙二醇在薄膜表面的接触角增大,CPP薄膜的表面亲水性减弱.  相似文献   

3.
氧传感器用ZrO2-Y2O3固体电解质电导性能的研究   总被引:20,自引:2,他引:18  
采用低温处理制备的ZrO2-Y2O3系列超细粉末,粉末粒度达到10-50nm,经压制、等静压成型、高温烧结成致密的氧化锆陶瓷。分别采用超细铂粉、专用铂电极浆料以及氯铂酸等原料制作电极,用交流电桥法测试各种陶瓷的导电性能,通过比较分析,基本确定了制备氧传感器的ZrO2-Y2O3系列固体电解质的组成。  相似文献   

4.
采用固相反应合成工艺在纳米ZrO2颗粒(ZrO2p)上进行BN包覆处理,通过SEM,TEM,DSC等手段对颗粒包覆情况及其作用效果进行研究.表明以H38O3,CO(NH2)2为原料,二者摩尔比为13、按BN与ZrO2的体积比为31设计,于750℃下氮化处理,可在ZrO2纳米颗粒上成功包覆厚度约10~50 nm的非晶BN纳米层.复合粉体的热分析和热压烧结制备的ZrO2p/BN-SiO2复合陶瓷材料组织观察证实,该涂层可有效阻止ZrO2与SiO2之间发生反应.  相似文献   

5.
采用湿化学法制备W-TiC复合粉体,然后采用放电等离子体烧结(SPS)技术制备超细晶W-TiC复合材料,并对其复合粉体形貌和烧结复合材料组织结构进行研究。结果表明,对原始TiC粉进行活化预处理,使TiC粉表面获得均匀分布的缺陷,提高TiC粉表面的的亲水性,通过化学还原获得第二相TiC颗粒,且均匀弥散分布于W基体晶界和晶粒内。采用SPS烧结技术获得的超细晶W-TiC复合材料晶粒尺寸为400 nm,致密度为95%,维氏显微硬度值HV0.2达到1280。  相似文献   

6.
邓爱民  穆锐  苏昭玮 《表面技术》2021,50(3):232-238
目的 比较三种不同改性方法对负离子粉表面改性的效果.方法 以KH-570为改性剂,分别采用球磨法、溶剂回流法和干研磨法对超细负离子粉进行表面有机化改性.将改性后的负离子粉分散到丙烯酸酯单体中,通过悬浮聚合在负离子粉表面生成聚合物包覆层,并制备成包含负离子粉的聚合物微球体.通过7230G分光光度计对比粉体在甲基丙烯酸甲酯单体中的悬浮性能.采用扫描电镜观察粉体的形貌特征以及聚合物包覆后粉体表面与聚合物的结合状况.分离出未被聚合物包覆的负离子粉,计算负离子粉的有效包覆率.采用COM-3010PRO负离子测试仪测试聚合物包覆前后负离子的释放性能.通过综合对比和分析,判断改性方法的优劣.结果 三种改性方法都可以实现对负离子粉表面的有机化改性.负离子粉表面有机化改性后,平均粒径减小,在甲基丙烯酸甲酯中分散悬浮稳定性明显增加.通过悬浮聚合可以得到聚合物包覆的负离子粉体微球,负离子粉在聚合物中分布均匀、结合牢固,聚合物有效包覆率最高可达79.2%.从改性后负离子粉的悬浮稳定性、聚合物包覆率、在聚合物中的分布状态以及负离子释放性能等方面,均体现出球磨法最优,溶剂回流法次之,干研磨法最差的规律.结论 球磨法是最佳的处理方法,负离子粉在聚合物中分布均匀,聚合物有效包覆率高,负离子释放量大.  相似文献   

7.
ZrO2(n)、SiC(W)的分散及与MoSi2基质的均匀混合工艺研究   总被引:1,自引:0,他引:1  
通过沉降实验并借助SEM观察探讨了不同分散剂、不同分散介质对纳米ZrO2颗粒分散效果的影响。介绍了SiC晶须分散工艺,探讨了多相悬浮液混合法制备ZrO2(n)/MoSi2复合粉体及SiC(w)/ZrO2(n)/MoSi2复合粉体的均匀混合工艺。结果表明:以PEG为分散剂、水为分散介质可以有效地分散纳米ZrO2并能与基体MoSi2粉末均匀混合;通过调节乙醇悬浮液的pH值,可将SiC晶须均匀分散在ZrO2(n)/MoSi2复合粉体中,获得分布均匀的SiC(w)/ZrO2(n)/MoSi2复合粉。  相似文献   

8.
以马来酸酐的等离子体聚合方法对聚丙烯薄膜表面进行了亲水改性,用FT-IR、接触角等分析手段研究了等离子体处理功率对改性薄膜表面的化学结构和亲水性能的影响以及薄膜表面的马来酸酐等离子体聚合物在高温强酸环境中的腐蚀行为.结果表明,马来酸酐等离子体聚合物可水解为聚马来酸结构,改性薄膜表面接触角达到43°~50°,接触角随处理功率的提高呈上升趋势.50W的马来酸酐聚合物的耐110℃、40%硫酸腐蚀性优于30W的马来酸酐聚合物;在高温硫酸介质的腐蚀环境下,马来酸酐的等离子体聚合物可通过磺化反应而引入亲水的磺酸基团,腐蚀后改性薄膜的表面接触角进一步降低至30°以下,获得了更佳的表面亲水性.  相似文献   

9.
以硝酸氧锆和钼酸铵等为原料,采用水热法合成了超细立方相ZrMO2O8粉体.分别采用XRD,FT-IR及SEM对前驱体及所得产物的结构及形貌进行了分析和表征.结果表明采用水热法可以快速(15 h)合成出单一纯净的超细立方相ZrMO2O8粉体,颗粒尺寸约为100 nm×500 nm,所得粉体具有优异的负热膨胀特性,在室温~400℃温度范围内,其热膨胀系数为-5.185×10-6K-1,适合工业化生产.  相似文献   

10.
王云英  陈玉如  孟江燕  孙旭 《表面技术》2013,42(6):55-58,82
目的 研究低密度聚乙烯( LDPE) 薄膜经低温等离子体处理前后,表面性能的变化情况。 方法 采用不同的处理条件,对 LDPE 进行低温等离子体处理,并对比 LDPE 薄膜处理前后的表面形貌、表面接触角及剥离强度。 结果 采用空气为处理气氛时,在功率 44 W、真空度 60 Pa 的条件下处理 30 s,LDPE薄膜的静态接触角从处理前的 101 o 降到 13 . 5 o ;等离子体处理后的 LDPE 薄膜在 1 h 内,接触角会迅速上升到 74 o ,失去等离子体处理的效果。 结论 对于处理气氛,空气比 N2 和 CO2 的处理效果更好;等离子体处理后的 LDPE 薄膜具有明显的时效性,应立即进入下道工序。  相似文献   

11.
The carbon steels dispersed with ultrafine TiC particles were fabricated by conventional casting method. The casting process is more economical than other available routes for metal matrix composite production, and the large sized components to be fabricated in short processing time. However, it is extremely difficult to obtain uniform dispersion of ultrafine ceramic particles in liquid metals due to the poor wettability and the specific gravity difference between the ceramic particle and metal matrix. In order to solve these problems, the mechanical milling (MM) and surface-active processes were introduced. As a result, Cu coated ultrafine TiC powders made by MM process using high energy ball milling machine were mixed with Sn powders as a surfactant to get better wettability by lowering the surface tension of carbon steel melt. The microstructural investigations by OM show that ultrafine TiC particles are distributed uniformly in carbon steel matrix. The grain sizes of the cast matrix with ultrafine TiC particles are much smaller than those without ultrafine TiC particles. This is probably due to the fact that TiC particles act as nucleation sites during solidification. The wear resistance of cast carbon steel composites added with MMed TiC/Cu-Sn powders is improved due to grain size refinement.  相似文献   

12.
化学镀法制备Ni包覆ZrO_2微粉   总被引:10,自引:0,他引:10  
采用共沉淀t-ZrO2(10%MgO,以摩尔计)微粉为基体原料,用化学镀法制备了不同Ni含量的Ni包覆ZrO2复合微粉.由于采用了合适的络合剂和稳定剂,反应速度易于控制,且粉末不需活化处理即可施镀.运用XRD、SEM、EPAX等分析检测技术研究了粉体.结果表明,镀覆后颗粒均由Ni和ZrO2两种成份复合而成,达到了均匀分散金属相和陶瓷相的目的  相似文献   

13.
The bulk Al-12 Si eutectic composites were fabricated through a conventional liquid metal casting route, especially with the help of ultrafine ceramic powders made by self-propagating high-temperature synthesis (SHS) process. The SHS powders were fabricated by the chemical reaction between micro-sized SiC and Al particles at very high combustion temperatures, producing the coarse Al particles (several tens of microns) containing ultrafine SiC ceramic particles. Microstructural observation revealed that the addition of ultrafine SiC particles has a crumbling tendency of Si eutectic phase. It is suggested that the casting method combined with SHS process is promising for fabricating the Al-based MMC with ultrafine ceramic particles.  相似文献   

14.
The bulk Al-12 Si eutectic composites were fabricated through a conventional liquid metal casting route, especially with the help of ultrafine ceramic powders made by self-propagating high-temperature synthesis (SHS) process. The SHS powders were fabricated by the chemical reaction between micro-sized SiC and Al particles at very high combustion temperatures, producing the coarse Al particles (several tens of microns) containing ultrafine SiC ceramic particles. Microstructural observation revealed that the ...  相似文献   

15.
李淑娟  刘祥萱  王煊军 《表面技术》2008,37(2):28-30,33
为了提高超细Ni粉的分散性能,提高其与有机介质的相容性,采用表面活性剂对超细Ni粉进行包覆;考察了表面活性剂类型、pH值、溶剂对Ni-表面活性剂复合粒子亲水亲油性能、分散性能和耐酸蚀性能的影响,显示十二烷基苯磺酸钠(DBSA)是一种优良的包覆剂;运用FTIR光谱和TEM分别对Ni-DBSA复合粒子的表面结构和形态进行了测试和表征.结果表明:pH=9、溶剂为去离子水时,Ni-DBSA复合粒子具有良好的核-壳结构,并且Ni粉表面完全被DBSA分子代替.  相似文献   

16.
等离子喷涂ZrO2热障涂层热冲击破坏研究   总被引:6,自引:0,他引:6  
李其连 《中国表面工程》2004,17(3):17-20,25
对比研究了等离子喷涂ZrO2梯度热障涂层及传统的双层结构热障涂层,选择NiCoCrAlTaY合金粉末作为热障涂层的粘结底层材料、7%Y2O3-ZrO2作为热障涂层的面层材料、不同比例的NiCoCrAlTaY与7%Y2O3-ZrO2(YPZ)复合粉末作为梯度过渡层材料,然后进行热冲击试验、金相分析及扫描电子显微镜形貌分析,结果表明梯度热障涂层热冲击寿命明显高于传统的双层结构热障涂层。  相似文献   

17.
Ultrafine Al2O3–TiC–Co (ATC) ceramic is prepared in order to improve the bending strength and fracture toughness of ceramic materials. The ultrafine Co‐coated Al2O3 and TiC powders have been synthesized by electroless plating at room temperature, and the composite powders were sintered by hot‐pressing to compact ATC samples. The average bending strength, average hardness and average fracture toughness values of ATC ceramic with different particle sizes and Co contents were investigated. The toughening mechanism of the ultrafine ATC ceramic was studied by transmission electron microscopy (TEM) and ceramic performance testing methods. The results show that the relative density, bending strength and fracture toughness values increase remarkably with the increase of Co content. The ultrafine grain of original powders is beneficial to improve the relative density, strength and toughness values of ATC ceramic. The Co phase hinders the growth of ATC ceramic grains during sintering. The Co phase forms a three‐dimensional mesh skeleton structure during sintering, improving the fracture toughness and strength of the composite ceramic.  相似文献   

18.
The carbon steels dispersed with ultrafine TiC particles were fabricated by conventional casting method. The casting process is more economical than other available routes for metal matrix composite production, and the large sized components to be fabricated in short processing time. However, it is extremely difficult to obtain uniform dispersion of ultrafine ceramic particles in liquid metals due to the poor wettability and the specific gravity difference between the ceramic particle and metal matrix. In order to solve these problems, the mechanical milling (MM) and surface-active processes were introduced. As a result, Cu coated ultrafine TiC powders made by MM process using high energy ball milling machine were mixed with Sn powders as a surfactant to get better wettability by lowering the surface tension of carbon steel melt. The microstructural investigations by OM show that ultrafine TiC particles are distributed uniformly in carbon steel matrix. The grain sizes of the cast matrix with ultrafine TiC particles are much smaller than those without ultrafine TiC particles. This is probably due to the fact that TiC particles act as nucleation sites during solidification. The wear resistance of cast carbon steel composites added with MMed TiC/Cu-Sn powders is improved due to grain size refinement.  相似文献   

19.
正交设计法优化高分散超细银粉的制备工艺   总被引:1,自引:0,他引:1  
以AgNO3为银源,抗坏血酸为还原剂,通过液相还原法制备了超细银粉。运用L25(56)的正交试验设计,考察了AgNO3浓度、抗坏血酸浓度、分散剂种类、分散剂用量、溶液pH值及反应温度对超细银粉的分散性及粒度的影响。分析得出制备超细银粉的优化条件:AgNO3浓度为0.15mol.L-1,抗坏血酸浓度为0.40mol.L-1,油酸为分散剂,分散剂用量为8%(相对AgNO3质量),pH值为4,反应温度为50℃。在优化的实验条件下,制备出高分散近球形的超细银粉,其平均粒度为0.89μm。并运用SEM、XRD对其进行了表征。  相似文献   

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