Intratumoral Thermal Reading During Photo‐Thermal Therapy by Multifunctional Fluorescent Nanoparticles

The tremendous development of nanotechnology is bringing us closer to the dream of clinical application of nanoparticles in photothermal therapies of tumors. This requires the use of specific nanoparticles that must be highly biocompatible, efficient light‐to‐heat converters and fluorescent markers. Temperature reading by the heating nanoparticles during therapy appears of paramount importance to keep at a minimum the collateral damage that could arise from undesirable excessive heating. In this work, this thermally controlled therapy is possible by using Nd³⁺ ion‐doped LaF₃ nanocrystals. Because of the particular optical features of Nd³⁺ ions at high doping concentrations, these nanoparticles are capable of in vivo photothermal heating, fluorescent tumor localization and intratumoral thermal sensing. The successful photothermal therapy experiments here presented highlight the importance of controlling therapy parameters based on intratumoral temperature measurements instead of on the traditionally used skin temperature measurements. In fact, significant differences between intratumoral and skin temperatures do exist and could lead to the appearance of excessive collateral damage. These results open a new avenue for the real application of nano­particle‐based photothermal therapy at clinical level.     

Locally Welded Silver Nano‐Network Transparent Electrodes with High Operational Stability by a Simple Alcohol‐Based Chemical Approach

As an indispensable aspect of emerging flexible optoelectronics, flexible transparent electrodes, especially those comprised of metal nanowires, have attracted great attentions recently. Welding the nanowire junctions is an effective strategy for reducing the sheet resistance and improving the operational stability of flexible nanowire electrode in practical applications. Herein, a simple alcohol‐based solution approach is proposed to weld crossed silver nanowires by chemically growing silver “solder” at the junctions of the nanowires, forming transparent silver nano‐network electrodes with improved electrical conductivity and operational stability. Remarkably, silver nano‐networks can be rapidly formed by this simple approach under ambient condition and room temperature, requiring no assistance from heat, light, electrical current, or mechanical pressure. Furthermore, our results show that the nano‐network electrode formed from large diameter nanowires offers a better operational stability, whose trend is opposite to that of the untreated electrodes. To demonstrate the potential application of the highly stable silver nano‐network from large diameter nanowires, organic solar cells fabricated on the nano‐network electrode incorporated with silicon dioxide nanoparticles achieve comparable performance to the ITO control device. Consequently, strategy demonstrated in this work can contribute to low‐cost and highly stable transparent electrodes in emerging flexible optoelectronics.     

Mn1-xZnxFe2O4 (0≤x≤1)纳米粉体的模板辅助溶胶凝胶法制备及其磁性能研究

通过模板辅助溶胶-凝胶法制备了一系列的Mn_1-xZn_xFe₂O₄(0≤x≤1,步长为0.2)纳米粉体。利用XRD和VSM对材料的物相和磁性能进行了表征,主要研究了Mn_1-xZn_xFe₂O₄分子式中Zn含量的变化对样品的微观结构和磁性能的影响。实验结果表明,具有不同Zn含量的Mn_1-xZn_xFe₂O₄样品均为尖晶石结构;随着Zn含量的增加,样品的晶面间距d、平均晶粒尺寸D、饱和磁化强度M_s和居里温度T_c都呈现出下降的趋势,而样品的矫顽力H_c则呈现出先升高后降低的趋势。分析认为,M_s的下降可以用Yafet-Kittel倾角理论解释,T_c的降低归因于晶格中反铁磁性耦合的降低,而H_c的变化则主要是由于材料的磁晶各向异性常数K₁的变化引起的。     

纳米ZnO和纳米MMT对低密度聚乙烯介电性能的影响

分别采用添加纳米ZnO和纳米蒙脱土(MMT)粒子的方法提高低密度聚乙烯(LDPE)的介电性能,选择偶联剂对纳米粒子进行表面修饰,并利用熔融共混法制备了纳米ZnO/LDPE和纳米MMT/LDPE复合材料,通过XRD、FTIR和DSC对试样进行表征。研究了复合材料的交流击穿特性,对试样进行了空间电荷试验。结果表明:通过偶联剂修饰,纳米粒子与聚合物之间的界面结合得到改善,且纳米粒子在基体中的分散性更好;同时复合材料的结晶速率提高,结晶结构更完善;添加纳米粒子可以不同程度地提高LDPE的击穿场强,当纳米ZnO和纳米MMT的质量分数均为3wt%时,复合材料的击穿场强达到最大,分别比纯LDPE的击穿场强高出11.0%和10.3%;纳米ZnO和纳米MMT都有抑制空间电荷的作用,且ZnO的抑制效果更明显。     

纳米铜修饰多壁碳纳米管/石蜡相变驱动复合材料的制备及热性能

以油胺为分散稳定剂,在石蜡中热分解甲酸铜-碳纳米管复合物前驱体,单步制备了纳米铜修饰多壁碳纳米管(Cu-MWCNTs)/石蜡复合材料。通过XRD、TEM和DSC对Cu-MWCNTs/石蜡复合材料的物相、微观形貌及相变行为进行了表征和分析,并对其热敏性、热膨胀性和热稳定性及影响因素进行了分析研究。结果表明:纳米Cu原位沉积在MWCNTs外壁上,粒径为2~35nm。与纯石蜡相比,Cu-MWCNTs/石蜡复合材料的相变温度和相变潜热均明显降低。Cu-MWCNTs含量为0.2wt%的Cu-MWCNTs/石蜡复合材料具有较短的升温时间,体膨胀率降低较小,且多次加热后稳定性较好,可作为此类热敏微驱动器的理想材料。     

易于微孔道填充的纳米CuO的制备

分别采用直接沉淀法和快速沉淀法成功地制备了易于微孔道填充的纳米Cu O粉末。直接沉淀法的铜源是无水Cu SO4,沉淀剂是Na2CO3;快速沉淀法的铜源是Cu(CH3COO)2·H2O,沉淀剂是Na OH。通过XRD、SEM、TEM和SAED等分析手段表征产物的晶体结构、微观形貌及晶粒尺寸。结果表明,直接沉淀法的陈化时间对制备样品形貌和结构有影响。当前躯体陈化时间为3 h时,直接沉淀法制备的Cu O纳米颗粒平均粒径约为25 nm;快速沉淀法制备的Cu O纳米颗粒平均粒径约为6 nm。与直接沉淀法相比,快速沉淀法制备的纳米Cu O粒径更小、颗粒分散更均匀。     

一维纳米氧化锌的制备及应用研究进展

本文对一维纳米氧化锌的制备方法进行了综述,包括气相法、液相法和模板法;重点讨论了一维纳米氧化锌在太阳能电池、传感器、多功能纺织品以及有机物光催化降解等方面的应用;指出了一维纳米氧化锌制备中存在的问题,并对其后续发展进行了展望.     

含能油墨配方设计及其在微孔装药中的应用

为优化微装药方法及设计合适的含能油墨配方,将喷墨打印装药和湿法压装两种装药方法结合起来,发现装药密度得到明显提高,装药均一性较好。采用激光点火方式,结合高速摄影和X射线衍射(XRD)等对微孔燃烧过程及其燃烧产物进行分析,获得了含能油墨中载体种类、纳米Al/Cu O含量和Φ值对微孔燃烧的影响规律。发现硝化棉(NC)不但有很好的油墨性能、装药性能,而且点火燃烧性能良好。得到以下结论:载体为NC且质量分数为7.5%,Al/Cu O的Φ值为1.6,初步测得最优配方下平均冲量约为145μN·s。     

蒸汽养护条件下纳米TiO2对粉煤灰水泥体系早期力学性能的影响

研究了蒸汽养护条件下纳米TiO2 (NT)对粉煤灰-水泥体系早期力学性能的影响,并探索了其影响机制.结果 表明:NT的掺入可显著提高粉煤灰-水泥体系的早期抗压强度,其最佳掺量为3％;NT的掺入显著提高了水泥熟料的水化程度及粉煤灰的二次水化程度,增加了水化硅酸钙(C-S-H)凝胶的聚合度;NT的掺入降低了粉煤灰-水泥体系的孔隙率及总孔容,改善了其孔径分布,从而提高了粉煤灰-水泥砂浆的密实度及早期抗压强度.