水凝胶sem拍不出多孔结构

扫描电镜检测是材料微观形貌观察必不可少的研究手段，但水凝胶材料由于含有大量水分或有机溶剂，无法直接放入电镜中观察。电镜工作需要维持高真空环境，而水分在真空中会迅速挥发，导致图像异常甚至电镜故障。

因此，对于水凝胶样品，通常需要进行冷冻干燥处理，将水分去除后再进行拍摄。

想准确测定厚度还是很麻烦的，关键就在于制样，关于镀层或者薄膜厚度的测定有相关标准的，标准名称我不太记得了，改天给你发过来也行（如果需要），大概意思是说在要测的镀层外面再镀一层镍，然后把材料固化在树脂中，再做截面，或者抛光，然后再测定，关键是不要破坏镀层.关于SiO2不导电的问题，喷金或者喷碳就可以解决.

帖子看到晚了一点，抱歉，翻译绝对专业，楼主一看就清楚了。

First, fine BaTi2O5 powders were made by a sol–gel method. Ba(OC2H5)2 and Ti[OCH(CH3)2]4 with a molar ratio of 1 : 2 were mixed in a solution of methanol and 2-methoxyethanol in a glove box with N2 gas flow. 首先用溶胶－凝胶制备微细的BaTi2O5粉末。将摩尔比为1：2的Ba(OC2H5)2 和Ti[OCH(CH3)2]4在甲醇和2甲氧基乙醇的溶液中混合，这在通氮气流的手套操作箱中进行。 The yellow clear solution obtained was put into a cool-stirrer (CSB-900 N) and was cooled to 0 ◦C to form a colorless transparent sol. 将得到的黄色清澈的溶液放进一个冷却搅拌器（CSB－900N）中，并冷却到0℃，从而形成一种无色透明的溶胶。Then it was sprayed with water for hydrolysis while being stirred until it became a transparent gel with a high viscosity. 然后将溶胶用水喷淋进行水解，同时进行搅拌，直至溶胶变成高粘度的透明凝胶为止。After it was aged at 50 ◦C for 24 h, we obtained a dark-yellow amorphous precursor which was subsequently pulverized, ground, and calcined twice, at 650 ◦C for 12 h andat 1000 ◦Cfor2 h, respectively. 在经过50℃下24h的老化后，我们就得到了一种暗黄色的无定形前驱体，它随后被粉碎、研磨和煅烧两次，分别在650℃下煅烧12h，和在1000℃下煅烧2h。As a consequence, white powders of BaTi2O5 with a size ranging from 20 nm to 200 nm were obtained. KF-doped BaTi2O5 ceramics were synthesized by solid state

reaction of mixed KF (Merck, 99%) and the above sol–gel-derived BaTi2O5 powders. 结果，得到了尺寸范围从20nm到200nm的BaTi2O5白色粉末。掺杂KF的BaTi2O5陶瓷用混合的KF（Merck公司，99％）和上面的溶胶－凝胶衍生的BaTi2O5粉末进行固态反应而合成。According to Shannon ionic radii values [10] and charge neutrality requirements, the chemical formula should be Ba1−xKxTi2O5−xFx . 根据香农离子半径值[10]和电荷中性要求，化学方程式应该为Ba1−xKxTi2O5−xFx 。Several compositions were made in this study: x = 0, 0.01, 0.02, 0.05, 0.097, and 0.24. 在本研究中制备了好几种组分：x = 0,0.01, 0.02, 0.05, 0.097, 和 0.24。The mixed powders were ground in ethanol and dried, then pressed into pellets with a uniaxial pressure around 300 MPa, and sintered at 1150 ◦C for 2 h in air.这种混合的粉末在乙醇中研磨，并干燥，然后用大约300MPa的单轴压力加压成小颗粒，并在1150℃下于空气中烧结2h。The phase purity was checked by XRD analysis using a Rigaku RINT2000 diffractometer with Cu Kα1 radiation. 用采用Cu Ka1辐射的Rigaku RINT2000衍射仪进行XRD（X射线衍射）分析，检验相纯度。The data were collected in step-scan mode with a step angle of 0.01◦ and a sampling time of 2 s. 用步进扫描方式采集数据，步进角度为0.01°，采样时间为2s。Microstructure observation was performed with a Hitachi S-3000N scanning electron microscope (SEM). Chemical composition was checked by electron probe microanalysis (EPMA). 用Hitachi（日立）S-3000N扫描电子显微镜（SEM）进行微结构观察。用电子探针微分析（EPMA）检验化学组分。The density of ceramic samples was calculated by measuring the thickness, diameter and weight of the pellets. 陶瓷样本的密度通过测量小颗粒的厚度、直径和重量加以计算。Dielectric measurements were carried out with HP 4284A and HP 4285A LCR meters over a frequency range of 100 Hz–10MHz and over a temperature range of room temperature to ∼ 560 ◦C. We used silver electrodes with gold lead wires which were fired at 500 ◦C. 用HP 4284A and HP 4285A万能表（LCR meter）在100Hz～10MHz频率范围和室温到560℃的温度范围联系了电介质测量。我们采用了带金引线的银电极，它们被在500℃下加以燃烧。

---