甲基官能化MCM-48分子筛的制备与表征

以甲基三甲氧基硅烷为偶联剂,用化学接枝法对MCM-48分子筛进行改性,制备了甲基官能化的MCM-48分子筛.利用FT-IR、XRD、低温N2吸附/脱附等手段对产物进行结构和性能分析.实验结果表明,硅甲基取代了MCM-48分子筛表面和孔道内羟基,成功接枝到MCM-48表面上,膜孔径、比表面积及孔体积均减小,但MCM-48保留原有立方有序结构.MCM-48分子筛甲基硅烷化改性后表面疏水性提高,水热稳定性提高.     

双官能基改性硅油的制备和表征

以八甲基环四硅氧烷(D4)、长链烷基甲基二甲氧基硅烷(HD-109)、N-β.氨乙基-γ-氨丙基甲基二甲氧基硅烷(YDH-602)和六甲基二硅氧烷(MM)为原料,在四甲基氢氧化铵(TMAH)催化下,采用本体聚合反应合成了一种新型硅油-氨基与长链烷基共改性硅油(ADMPS).对实验条件进行了优化探索,结果表明:反应温度110～115℃、反应时间8h、YDH-602和HD-109用量占D4的质量分数分别为7%～8%和9%时,可获得黏度适宜、应用性能较好的双官能基硅油.用红外光谱、核磁共振氢谱对其结构进行了表征.     

石墨烯红外低发射率涂料制备及性能研究

将石墨烯应用在红外低发射率涂料中,研究了其漆膜电导率、红外发射率和力学性能.研究表明,当石墨烯添加量为1.5%时,电阻率降至0.59×10^6Ω·cm,漆膜发射率可降至0.13,相对传统纯金属的,红外低发射率漆膜红外发射率明显降低,且漆膜具有更优异的力学性能.     

绝缘栅双极晶体管表面电沉积镍基石墨烯薄膜的制备及其散热性能研究

将镍基石墨烯薄膜应用在IGBT模块散热方面,提出了镍基石墨烯薄膜的制备工艺,并利用扫描电镜、透射电镜、能谱仪等对镍基石墨烯薄膜进行表征。结果表明,当电流密度为2 A/dm~2时,镍基石墨烯薄膜中的有大量的Ni和C元素,镍基石墨烯薄膜中的石墨烯平均粒径为32.5 nm。当脉冲电流密度为1 A/dm~2时,镍基石墨烯薄转移镍基石墨烯薄膜后的S1芯片的散热效果较好。当脉冲电流密度为2 A/dm~2时,镍基石墨烯薄转移镍基石墨烯薄膜后的S2芯片的散热效果最好,其最大散热量为14.9℃。     

以环糊精为核的星形七臂官能化聚己内酯的制备与表征及生物素修饰

以含有7个羟基的乙酰化β-环糊精为引发剂,开环聚合4-氨基甲酸苄酯-ε-己内酯(CABCL)单体,得到星形七臂官能化聚己内酯(CDSPCABCL)。并使用酸脱法与钯碳氢解法对CDSPCABCL的甲酸苄酯保护基脱保护,得到星形聚氨基己内酯(CDPACL)。同时,探索了投料比、聚合温度、聚合时间对CDSPCABCL聚合度的影响,以及酸脱法的酸倍数与反应时间、钯碳氢解法的反应时间对CDPACL断链率与脱保护率的影响。通过1 H NMR、GPC、FT-IR与TGA表征各步骤产物。最后通过CDPACL的氨基与生物素的羧基发生酯化反应,得到生物素化的星形聚己内酯,其在癌细胞靶向、生物探针等领域有潜在的应用前景。     

环氧底面合一防腐耐候涂料的制备

底面合一涂料可缩短施工周期,降低施工费用。选用氢化环氧树脂、超支化增韧树脂和脂环胺固化剂作为涂料的成膜物体系,辅以防腐耐候型颜填料,制备出底面合一防腐耐候涂料。结果表明：经与普通双酚A型环氧树脂涂层性能对比,底面合一防腐耐候涂料涂层可耐人工气候老化(UVB)和划叉盐雾2000h,涂层变色2级,粉化1级,不起泡、不开裂、不脱落,附着力高,施工性能好,可应用在船舶及其他钢结构,同时还可在极低温度下应用,在极寒地区有较好的应用前景。     

耐高温防腐隔热涂料的制备与性能

耐高温防腐隔热涂料在石化管道领域具有重要的应用。文中以环氧改性有机硅树脂为基料,通过复配具有优异隔热性能的空心玻璃微珠、低温熔融玻璃粉、润湿分散剂、消泡剂等制备了一种至少耐500℃高温的防腐隔热涂料。利用扫描电子显微镜、热导分析、电化学阻抗谱,研究了不同颜基比、空心玻璃微珠含量对涂料力学性能和热学性能的影响。研究表明,颜基比为2/1,空心玻璃微珠占填料比例为40%时涂层综合性能达到最佳。     

双端呋喃官能化聚异戊二烯的合成及表征

采用阴离子聚合方法,以双锂引发剂引发异戊二烯聚合并以2-((环氧乙烷-2-基甲氧基)甲基)呋喃(FGE)为封端剂制备双末端含呋喃基团的聚异戊二烯。利用核磁共振和红外光谱对呋喃官能化聚异戊二烯的封端效率进行检测;利用凝胶渗透色谱、基质辅助激光解吸电离飞行时间质谱和差示扫描量热仪对其相对分子质量及分布和热性能进行分析。结果表明,官能化封端效率大于95%;聚异戊二烯的分子量分布指数(PDI)为1.07(<1.1),符合活性阴离子聚合窄分布的特点;由于聚异戊二烯的1,4-结构含量较低且链端存在的呋喃环使得内旋转位阻增大,双端呋喃官能化聚异戊二烯的玻璃化转变温度比未封端的略有升高。这种高效呋喃封端方法为构建理想动态交联网络的橡胶材料提供了新的途径。     

共价功能化碳化硅-磺化聚苯胺/环氧树脂防腐复合涂层的制备及防腐性能

聚合物/无机物纳米复合材料由于其独特的性能成为目前材料研究的热点之一。为得到疏水性能及防腐性能俱优的碳化硅（SiC）防腐复合涂层材料,利用硅烷偶联剂（KH-550）对碳化硅（SiC）纳米粒子进行氨基化处理,然后以苯胺、氨基苯磺酸和氨基化SiC纳米粒子为原料,通过一步法氧化聚合反应合成共价功能化碳化硅-磺化聚苯胺（SiC-NH₂-SPANI）复合材料,采用FT-IR、UV-vis、XRD和SEM对复合材料的微观结构和形貌进行表征分析。最后通过喷涂法将SiC-NH₂-SPANI复合涂层材料涂覆于基材上并对其进行性能测试,主要研究涂层的疏水性能和防腐性能;并探讨了不同SiC纳米粒子和过硫酸铵（APS）的反应量以及复合材料加入量对共价功能化碳化硅-磺化聚苯胺/环氧树脂（SiC-NH₂-SPANI/EP）防腐复合涂层的影响。研究结果表明,加入质量分数为3wt%SiC-NH₂-SPANI的复合涂层具备较优的疏水性能,接触角（CA）值达到99.87°。SiC纳米粒子和过硫酸铵反应量对涂层防腐性能研究结果表明,当S...     

共价功能化石墨烯超疏水防腐复合涂层材料的制备

石墨烯/有机聚合物复合涂层材料较纯聚合物材料具有更优越的阻隔性能,然而由于石墨烯之间高表面能和分子间作用力,使石墨烯在防腐等领域的应用潜力无法充分发挥。本文首先以传统自由基共聚方法合成一种含氟丙烯酸酯共聚物,并采用丙炔胺对氧化石墨烯改性合成炔基化氧化石墨烯,然后利用含氟丙烯酸酯共聚物末端氰基通过点击化学反应以共价键形式接枝在炔基化氧化石墨烯表面。疏水性分析表明,含氟共聚物功能化石墨烯的水接触角达到153°,将制备的功能化石墨烯涂敷于钢板基体时,水接触角提高到171.3°。扫描电镜显示,在炔基化石墨烯表面生长有大量300~600 nm的半球形接枝物。同时,将含氟共聚物功能化石墨烯/环氧树脂复合材料应用于碳素结构钢中,通过Tafel曲线和电化学阻抗谱对其耐蚀性能进行表征。结果显示,氟化石墨烯含量为0.5wt%的复合涂层的电流密度I_corr最低(8.872×10?9 A/cm2),比其他涂层样品低1~2个数量级。综上所述,本实验所制备的涂层材料具有良好的防腐性能,这一研究为开发石墨烯防腐蚀涂层材料提供了一种新的策略。      

Preparation and characterization of TiO2/ZnO composite coating on carbon steel surface and its anticorrosive behavior in seawater

The TiO₂/ZnO composite coatings with various atomic ratios of Ti to Zn were prepared on carbon steel surface via sol–gel process followed by thermal treatment at different temperature. The as-prepared coatings were characterized through X-ray diffraction method, scanning electron microscopy, energy dispersive X-ray spectroscopy, and their anticorrosive behaviors in sterilized seawater were electrochemically assessed. The obtained coatings were quite thin even for the 8-layer samples. The thermal treatment at 500 °C led to severe oxidation of the steel substrate. The incorporation of ZnO avoided crack formation and refined the particles of the composite coatings. The electrochemical measurements of both the potentiodynamic polarization curves and electrochemical impedance spectroscopy revealed a substantial protection of the coatings for the substrate. In particular, the 8-layer TiO₂/ZnO composite coatings with atomic molar ratios of Ti to Zn of 1/1 and 1/3 after thermal treatment at 500 °C showed better anticorrosive performances than others.     

Preparation and characterization of rapamycin-loaded PLGA coating stent

In this study, using polylactic acid-co-glycolic acid (PLGA) with a molecular weight of 95,800 Da as drug carrier, three dose (low, moderate, high) rapamycin-eluting stents and the corresponding coating films were prepared. The pre- and post-expansion morphology of the rapamycin-eluting stent was examined by scanning electron microscopy (SEM), indicating that the coating was very smooth and uniform. The coating had the ability to withstand the compressive and tensile strains imparted without cracking from the stent during expansion process. There were many voids on stent coating surface after released for 18 days in release medium. The thermodynamics data of the stent coating film measured by differential scanning calorimetry (DSC) showed a lack of measurable solubility of rapamycin in the PLGA matrix. The release behavior of rapamycin from stent surface had a two phase release profile with a burst release period of about 2 days, followed by a sustained and slow release phase. The mass loss behavior of PLGA appeared linear throughout most of the degradation period, corresponding to an approximately constant mass loss rate. The platelet adhesion tests showed that the rapamycin-eluting films may have a good blood compatibility compared with control samples. Take into these results account, this novel rapamycin-eluting may be a good candidate to resolve in-stent restenosis.     

Nanoscale synthesis and characterization of graphene-based objects

Graphene-based nano-objects such as nanotrenches, nanowires, nanobelts and nanoscale superstructures have been grown by surface segregation and precipitation on carbon-doped mono- and polycrystalline nickel substrates in ultrahigh vacuum. The dominant morphologies of the nano-objects were nanowire and nanosheet. Nucleation of graphene sheets occurred at surface defects such as step edges and resulted in the directional growth of nanowires. Surface analysis by scanning tunneling microscopy (STM) has clarified the structure and functionality of the novel nano-objects at atomic resolution. Nanobelts were detected consisting of bilayer graphene sheets with a nanoscale width and a length of several microns. Moiré patterns and one-dimensional reconstruction were observed on multilayer graphite terraces. As a useful functionality, application to repairable high-resolution STM probes is demonstrated.     

Nanoscale synthesis and characterization of graphene-based objects

Abstract

Graphene-based nano-objects such as nanotrenches, nanowires, nanobelts and nanoscale superstructures have been grown by surface segregation and precipitation on carbon-doped mono- and polycrystalline nickel substrates in ultrahigh vacuum. The dominant morphologies of the nano-objects were nanowire and nanosheet. Nucleation of graphene sheets occurred at surface defects such as step edges and resulted in the directional growth of nanowires. Surface analysis by scanning tunneling microscopy (STM) has clarified the structure and functionality of the novel nano-objects at atomic resolution. Nanobelts were detected consisting of bilayer graphene sheets with a nanoscale width and a length of several microns. Moiré patterns and one-dimensional reconstruction were observed on multilayer graphite terraces. As a useful functionality, application to repairable high-resolution STM probes is demonstrated.     

功能化纳米TiO2/环氧树脂超疏水防腐复合涂层的制备与性能

超疏水材料在金属防腐领域具备巨大的潜在应用前景。为得到疏水性能及防腐性能俱优的纳米TiO₂/环氧树脂复合涂层材料,首先以三甲氧基十七氟癸基硅烷和γ-氨丙基三乙氧基硅烷(KH550)对纳米TiO₂表面功能化;以全氟辛基甲基丙烯酸酯对固化剂二乙烯三氨(DETA)进行氟化;最后通过一步共混法和两步喷涂法分别制备出两种复合涂层。利用FTIR、XPS、1HNMR分析氟化固化剂(F-DETA)和氟化纳米TiO₂(f-TiO₂)的物相组成和组织结构。接触角测试仪和静置实验表明,当三甲氧基十七氟癸基硅烷和γ-氨丙基三乙氧基硅烷的摩尔比为1∶15时f-TiO₂的性能最佳,所制备的复合涂层接触角达到164.9°。SEM表征结果显示通过两步法制备的f-TiO₂/环氧树脂复合涂层具备更均匀的粗糙表面、涂层内部孔隙率较低且环氧树脂层与f-TiO₂层具备梯度结构。摩擦实验证明两步法制备的f-TiO₂/环氧树脂复合涂层的超疏水性具备较好的机械稳定性。Tafel极化曲线和电化学阻抗谱(EIS)研究表明,通过两步法制备的f-TiO₂/环氧树脂复合涂层具有优异的防腐性能,其腐蚀抑制效率高达99.99%。      

功能性调湿材料的制备与表征

以羧甲基纤维素钠(CMC)为基质材料,并添加无机盐、致孔剂制备调湿材料,考察了无机盐种类与用量、致孔剂碳酸氢铵(NH4HCO3)用量对调湿材料性能的影响,并用傅里叶红外变换光谱(FT-IR)、扫描电镜(SEM)对样品的化学结构和表面形态进行表征。结果表明,m(CMC)∶m(无机盐LiCl)∶m(NH4HCO3)=6∶3∶4时,所制备的调湿材料在不同湿度环境下(80%、60%和40%RH)吸湿量达132%、55%和30%,并具有较高的湿容量。     

有序石墨烯导电炭薄膜的制备

采用Hummers法合成氧化石墨,在水中超声分散获得氧化石墨烯水溶胶,通过微滤法使氧化石墨烯片定向流动组装,制得氧化石墨烯薄膜.再通过化学还原和热处理使所制氧化石墨烯薄膜脱氧重石墨化,保持其形貌时可控制其导电性,制得电导率为184.8S/cm的石墨烯导电炭膜.