近红外线吸收纤维的组成、结构与性能研究

以碳化锆、碳化硅和聚丙烯为原料。熔融皮芯复合纺丝制成了具有不同组成和结构的近红外线吸收纤维，并采用DSC、单纤维强力仪、红外灯和点温计等测试了纤维和非织造布的性能。结果表明，陶瓷粉的种类、添加量以及添加方式均影响纤维的近红外线吸收性能，皮层中含有4％(质量分数)碳化锆的纤维具有最佳近红外线吸收性能。     

光热膜蒸馏用光热转换材料的研究现状

面对全球淡水资源的短缺,光热膜蒸馏因具有能源环保可持续、低能耗、高截盐、不易结垢等优势成为极具吸引力的新型海水淡化技术,其渗透通量与膜的光热转换性能密切相关。介绍了以金属纳米材料、无机半导体材料、碳基材料、聚合物材料及其他材料为光热转换材料的光热膜蒸馏的研究进展,并指出光热膜蒸馏面临的主要挑战和对未来的展望。     

热分解法制备Cu空心微球及其光热转换性能

以甲酸铜-辛胺配合物为前驱体,油胺为表面活性剂,在熔化液态石蜡中通过热分解法单步制备Cu空心微球。利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、X射线衍射仪(XRD)、导热系数仪、紫外-可见-近红外分光光度计(UV-Vis-NIR)及光热转换测试装置表征Cu球,研究其光热转换性能,分析Cu空心微球的合成机理。结果表明:反应温度为110℃、反应时间为3h、油胺物质的量为0.005mol的条件下,能够获得Cu空心微球,其平均粒径为380nm,壁厚约为70nm。Cu空心微球的形成机理:油胺吸附的Cu纳米晶在界面能最小化的驱动下,沿着前驱体热分解反应,生成的气泡和液态石蜡所形成的气-液界面聚合生长而成。Cu空心微球悬浮液的热导率、光热转换性能均优于实心Cu悬浮液的。     

太阳光热转换吸收薄膜制备方法:现状与发展

在简要叙述太阳光热转换吸收薄膜原理以及当前常用的电镀法和物理气相沉积法制备技术的基础上,着重阐述了作为湿化学技术的溶胶-凝胶法制备太阳光热转换吸收薄膜的进展,结合当前获得的以溶胶-凝胶法分别在甲醇和乙醇中制备Ni-Al_2O_3金属陶瓷薄膜的2个例子,讨论了溶胶-凝胶法需要注意的几个问题,提出了发展水基溶胶-凝胶法的方向.     

陶瓷基碳纳米管复合膜的光热膜蒸馏性能研究

构筑新型光热多功能蒸馏膜界面具有重要的研究价值,本研究以氧化铝(Al₂O₃)陶瓷膜作为载体,通过原位化学气相沉积(CVD)过程制备了氧化铝-碳纳米管(Al₂O₃-CNTs)复合膜,复杂交错的CNTs网络结构同时为复合膜提供了较好的疏水性以及高效的光热转换性能.Al₂O₃-CNTs膜的氮气渗透性为1 135.14 m³/(m²·h·MPa),水接触角达到171.0°,液体渗透压力为0.15 MPa.复合膜在模拟太阳辐照下辐照600 s后,表面温度升高至82.7℃,光吸收率最高可达66.2%.通过研究传统膜蒸馏及光热膜蒸馏性能,结果表明,在进料液温度为75℃,流速为60 r/min,进料液质量分数为3.5%NaCl溶液的情况下,相比于传统膜蒸馏过程,该复合膜在4 kW/m²的模拟光照强度下,通量提升率为33.7%,太阳能利用效率达到22.7%,同时盐截留率(>99.8%)和渗透侧电导率(&...     

超疏水光热转换材料的研究进展

光热转换材料可以将可再生的太阳能高效转换为热能,并在海水淡化、废水净化等领域取得了良好效果,但受限于材料本身的性质缺陷,难以大规模应用。最近的研究表明,超疏水特性可防止污染物附着在材料表面的光热位点,研究者通过超疏水改性,赋予了光热转换材料以优异的自清洁性能。该创新策略极大地提高了光热转换材料的稳定性和持久性,为光热转换材料的实际推广应用提供了可能性。详细介绍了超疏水改性的方法、过程和机理,并重点综述了超疏水光热转换材料的最新研究进展和应用案例。最后,辩证分析了超疏水光热转换材料面临的挑战以及优化策略,进一步展望了超疏水光热转换材料的发展趋势和工程应用前景。     

有机复合相变材料光热转换和储热性能的研究进展

有机相变材料具有过冷度低、无析出、性能较稳定以及熔点温度与中低温储热系统的应用温度相匹配等优点,受到了众多研究人员和工业界人士的关注。但有机相变材料导热系数低、光热转换效率差的缺点限制了其在太阳能光热转换中的进一步应用。将金属基、碳基等材料与有机相变材料进行复合是提高其性能的有效途径。本文介绍了常见的有机复合相变材料制备方法,并对其制备流程和优缺点进行了讨论,分析了不同添加剂和制备方法对有机复合相变材料的光热转换效率、导热系数、相变焓乃至形状稳定性的影响,并对其应用前景进行了展望。     

生物炭/二十烷复合定型相变材料制备及其光热、电热转换和储存性能

为解决单一有机相变材料二十烷(n-Eicosane)导热性差及在相变过程中易发生泄漏的问题,本实验选取玉米秸秆作为生物质原料,通过700℃高温热解、KOH刻蚀改性制备了具有多级孔道结构的生物炭(KBC)材料,再通过乙醇熔融、真空浸渍的方法将二十烷封装到生物炭内部孔道,得到了一种生物炭/二十烷(KBC/n-Eicosane)复合定型相变材料。通过SEM、XRD、FTIR等表征手段研究了复合材料的微观结构和形貌,同时利用TG及DSC测试了复合相变材料的热稳定性和储热性能,并探讨了复合相变材料中二十烷不同用量与焓值的关系。结果表明,复合相变材料的焓值与二十烷的用量成正比,当复合相变材料中生物炭与二十烷的质量比为1∶2时,复合相变材料未明显泄漏,定型效果良好,此时对应的熔融焓和凝固焓值分别为121.3 J·g^-1和117.6 J·g^-1,经过100次循环储热和放热性能测试后,未产生渗漏现象,相变焓值亦无明显变化,表明该复合相变材料的储热能力和稳定性较好。此外,还通过模拟太阳光辐射和接入直流电源的方式测试了复合相变材料的光热转换和电热转换能力,结果表明...     

Understanding the Photothermal Conversion Efficiency of Gold Nanocrystals

Plasmon‐based photothermal therapy is one of the most intriguing applications of noble metal nanostructures. The photothermal conversion efficiency is an essential parameter in practically realizing this application. The effects of the plasmon resonance wavelength, particle volume, shell coating, and assembly on the photothermal conversion efficiencies of Au nanocrystals are systematically studied by directly measuring the temperature of Au nanocrystal solutions with a thermocouple and analyzed on the basis of energy balance. The temperature of Au nanocrystal solutions reaches the maximum at ～75°C when the plasmon resonance wavelength of Au nanocrystals is equal to the illumination laser wavelength. For Au nanocrystals with similar shapes, the larger the nanocrystal, the smaller the photothermal conversion efficiency becomes. The photothermal conversion can also be controlled by shell coating and assembly through the change in the plasmon resonance energy of Au nanocrystals. Moreover, coating Au nanocrystals with semiconductor materials that have band gap energies smaller than the illumination laser energy can improve the photothermal conversion efficiency owing to the presence of an additional light absorption channel.     

Cooperative Strategies for Enhancing Performance of Photothermal Therapy (PTT) Agent: Optimizing Its Photothermal Conversion and Cell Internalization Ability

Photothermal conversion ability (PCA) and cell internalization ability (CIA) are two key factors for determining the performance of photothermal agents. The previous studies mostly focus on improving the PCA by exploring new photothermal nanomaterials. Herein, the authors take the hybrids of graphene and gold nanostar (GGN) as an example to investigate the gradually enhanced phototherapy effect by changing the PCA and CIA of photothermal therapy (PTT) agent simultaneously. Based on the GGN, the GGN and the reduced GGN protected by bovine serum albumin (BSA) or BSA‐FA (folic acid) are prepared, which are named as GGNB, rGGNB, and rGGNB‐FA, respectively. The rGGNB showed an enhanced PCA compared to GGNB, leading to strong cell ablation. On the other hand, the 1,2‐dioleoyl‐3‐trimethylammoniumpropan (DOTAP) can activate the endocytosis and promote the CIA of rGGNB, further help rGGNB to be more internalized into the cells. Finally, rGGNB‐FA with the target ability can make itself further internalized into the cells with the aid of DOTAP, which can significantly destroy the cancer cells even at the low laser density of 0.3 W cm^?2. Therefore, a new angle of view is brought out for researching the PTT agents of high performance.     

Photothermal therapy by using titanium oxide nanoparticles

The photothermal therapy (PTT) technique is regarded as a promising method for cancer treatment. However, one of the obstacles preventing its clinical application is the non-degradability and biotoxicity of the existing heavy-metal and carbon-based therapeutic agents. Therefore, a PTT material with a high photothermal efficiency, low toxicity, and good biocompatibility is urgently wanted. Herein, we report a titanium oxide-based therapeutic agent with a high efficacy and low toxicity for the PTT process. We demonstrated that Magnéli-phase Ti₈O₁₅ nanoparticles fabricated by the arc-melting method exhibit >98% absorption of near infrared light and a superior photothermal therapy effect in the in vivo mouse model. The Ti₈O₁₅ nanoparticle PTT material also shows a good biocompatibility and biosafety. Our study reveals Magnéli-phase titanium oxide as a new family of PTT agents and introduces new applications of titanium oxides for photothermal conversion.

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光热增强光催化性能二氧化钛(B)/玻纤布复合研究

以玻璃纤维布为基底, 以TiH₂为原料, 通过简易的化学合成及溶胶-凝胶法制备了光热增强光催化性能的二氧化钛(B)/玻璃纤维布复合材料(B-T/GFC)。通过XRD、SEM和TEM检测合成材料的成分、结构和形貌, 采用分光光度计、光学接触角测量仪、太阳光模拟器对材料的性能进行了系统研究。结果表明: 该复合材料表面形成了锐钛矿晶型的黑色TiO₂薄膜, 且晶体中存在厚度约为1 nm的无序层。同时该复合材料在250~2000 nm波长范围内具有较强的光吸收能力, 且具有强疏水性; 在 1 个太阳光强度下(1 kW/m ²), 相对于玻璃纤维布具有更强的光热能力; 其光催化降解切削废液中有机污染物(COD)的能力优于黑色TiO₂(B-T)和P25, 光照2 h的降解率约为P25的2.3倍。由此可见, B-T/GFC复合材料具有优异的光热增强光催化性能, 具有广阔的应用前景。     

AA6063铝合金着色Zr无铬转化膜及其电化学性能

以锆盐为主要原料,实现常温下对AA6063铝合金的无铬化学转化处理。采用SEM,XRD及电化学测试研究了转化膜的性能。结果表明:锆膜生长是以针状小单元结构组织成圆形较大的单元,再发展为均匀的黑灰色转化膜;锆膜厚约8.79μm,主要由KZrF_3(OH)_2·H_2O及KZrF_3O·2H_2O组成;锆膜耐腐蚀性能比铝合金提高了数百倍,与铬酸盐转化膜相当;锆膜的耐腐蚀性能与后处理工艺有一定关系,膜层结构等效电路为R_1+C_2/R_2+M_3。     

连续纤维增强SiC复合材料制备工艺与性能研究进展

综述了国内外碳纤维与碳化硅纤维增强碳化硅复合材料的制备工艺与性能的研究进展,并介绍了其氧化性能及防护措施.认为连续纤维增强SiC复合材料的制备工艺复杂,成本较高,生产周期长,但是如果采用连接技术制备成陶瓷/金属复合构件使用,既有利于降低成本,又能够扩大该先进陶瓷基复合材料的应用范围.目前,国内对连续纤维增强的SiC复合材料与金属(如高温合金等)的连接技术研究较少.     

Formation of Carbide Coatings on Nicalon Fiber by Gas-Phase Transport Reactions

Problems concerning the formation of coatings composed of the carbides of metals of the IV–V groups on Nicalon fiber under conditions of chemical transport through the gas phase are considered. Chemical reactions are considered which proceed in the zone of metal and fiber disposition. Scanning electron microscopy study shows that the formed carbide coatings are uniform and possess a high adhesion to the fiber.     

一种具有稳定富碳表层的SiC纤维的制备与性能

采用不饱和烃不熔化处理后的聚碳硅烷（PCS）纤维经高温烧成可制得一种新型的SiC纤维,纤维的抗张强度达2.5~2.8GPa,氧含量4wt%~6wt%,电阻率仅为0.5Ω·cm左右,大大低于采用传统空气不熔化方法得到的SiC纤维.研究表明:该纤维表面存在厚度约50nm的富碳层,并且在Ar气中进行高温热处理后,表面富碳层结构无明显变化.与日本通用级SiC纤维Nicalon NL202 相比,纤维的耐热性提高200~300℃.纤维具有低电阻率稳定性,从室温到1600℃,其电阻率始终保持在0.4~0.8Ω·cm.