Hydrogel morphology of particle positions can be characterized by using volume-imaging methods such as the focused ion beam scanning electron microscope (FIB-SEM) or the serial block-face scanning electron microscope (SBFSEM) techniques.

Kusha Sharma

It depends on the size of your microemulsion. Typically, SEM can offer enough resolution to image the emulsions if they are more than 1 micro-meter in diameter. If they are even bigger, optical microscopy might be an easier method but SEM surely can do the job.

Hi, consider that TEM is in transmission, so it might not be a proper technique to study a thick drop of gel (even if you get an image it might be hard to interpret properly), so you might have to cut slice of you sample.

SEM, on the other hand, looks at the surface of the sample which might give you an idea of the porosity and structure of the material. Of course, unless you use cryo techniques, you will have to dry your sample (by lyophilization of CO2 supercritical).

As mentioned in another comment, other techniques might be good too. Confocal microscopy, if your sample is fluorescent or can be tagged with fluorescent molecules, might give you a 3D of you sample (of course the resolution is definitely lower than that of SEM).

It largely depends on the information you want to get from the sample. We usually use SEM to study the obtain pore-size distribution and structure together with a porosimetry assay. The main disadvantage of this technique is the dehydration process, which may distort the structure of the scaffold and give you a non-real information (unless you use cryo-SEM, of course). In case you do not need so high resolution, confocal microscopy is a good option too. The good news here are that you do not need to dehydrate the sample and sometimes the structure of your hydrogel exhibits autofluoresnce (otherwise, you have to label it).

Another option is atomic force microscopy (AFM), which gives you so valuble information of the surface (topography and mechanical properties) and may be carried out in hydrated state too.

I would not use TEM unless you need to explore something very particular. The nature of your 3D scaffold will lose its essence at a significative extent.

The resolution of the TEM is higher (up to 0.08 nm), it seems to be more suitable

TEM can be useful as it has high resolution.

It is better to analyze your material first in FESEM to see how the morphology looks like, sometimes in hydrogel kind of structure you may see interconnected pores due to which it provides good surface area. The high surface area of your material will be beneficial for your desired application. After FESEM study you can go for TEM analysis.

All the best.

It depends on upon materials you are going to characterize

generally, HRTEM has a higher resolution than SEM by a factor of 10 or more

Kusha Sharma

You are working with a hydrogel. The hydrogel morphology depends on the water content. Water evaporates in vacuum TEM and CEM. Therefore, the hydrogel morphology cannot be investigated by these methods. To characterize mechanical properties, they are used by rheological methods.

Dear Rogelio

They are important techniques in research, only it is difficult to choose one, since they are complementary

SEM offers us information on the relief of cell surfaces and their support (hydrogel), analyzing their external morphological characteristics and their topographic disposition and

TEM is focused on the internal analysis of the ultrastructural fine architecture of the hydrogel with the cellular components (cell membrane, intracytoplasmic organelles) or elements of the estracellular matrix, as well as their fine interactions.

SEM is suitable for studying of surface morphology and hydrogel porosity. If necessary, you can also use FESEM, which in addition to morphology, will provide you with the elemental composition (percentage of elements except hydrogen) and how the elements are distributed on the hydrogel surface.