Investigating materials formation with liquid-phase and cryogenic TEM

Yoreo, Jim De; Sommerdijk, Nico A. J. M.

doi:10.1038/natrevmats.2016.35

Cited by 174 publications

(141 citation statements)

References 128 publications

Supporting

Mentioning

137

Contrasting

Unclassified

Order By: Relevance

“…[3,37] Importantly, as a major distinction from the analysis of static samples, the screening time of an individual droplet is extremely short, and data are recorded as a summation over a large number of identical droplets. The effect of the analysis process on the reaction being studied is therefore minimized or eliminated, where this can be a problem when high energy techniques such as synchrotron-based methods [38] or liquid-cell Transmission electron microscopy (TEM) [39] are used to investigate static samples.…”

Section: Discussionmentioning

confidence: 99%

Passive Picoinjection Enables Controlled Crystallization in a Droplet Microfluidic Device

Zeng

Gaule

et al. 2017

Small

View full text Add to dashboard Cite

in parallel, enabling large data-sets to be generated for statistical analysis. One of the most convenient ways of generating large numbers of identical droplets is using microfluidic devices. [2] These can be used to create static arrays and continuously flowing droplets, and a wide range of techniques are available for onchip analysis. [3,4] Microfluidic systems are therefore attracting increasing attention for applications such as studying nucleation kinetics, [5,6] for screening protein crystallization conditions and generating large protein crystals for structural analysis, [7][8][9] and for exploring polymorphism in organic [10,11] and inorganic crystal systems. [12][13][14] A range of strategies have been used to achieve on-chip crystallization. Protein crystals are often highly soluble such that precipitation can be effectively achieved by combining protein and precipitant solutions at the point of droplet formation, [6,8] or controlling water removal from the plugs of protein solution. [15] More complex strategies have also been explored to promote the formation of high quality crystals including valve-based systems, [9,16] merging of alternate droplets containing protein and precipitant, and separation of nucleation and growth events, [17] where additional protein/ precipitant is added to existing plugs downstream of the point of initial droplet formation. Crystallization of soluble organics and inorganics has also been achieved via droplet-shrinkage [18] and on-chip temperature control. [11,13] Many crystal systems that are important to industry, the environment, and biology-such as calcium carbonate, sulfate, and phosphate-are highly insoluble, however, which results in short induction times and makes on-chip study of their precipitation more challenging due to problems with device fouling. [12] While precipitation within droplets rather than single-phase systems greatly reduces channel fouling, [19] the formation of supersaturated droplets by combining cation and anion solutions using a conventional "Y-shaped" channel or equivalent inevitably leads to precipitation at this junction. This can give rise to a range of problems including the introduction of crystal seeds into droplets. These issues can be minimized, or even eliminated, using droplet fusion-where pairs of droplets are fused using special channel architectures or applied fields [20] -or direct injection strategies, where use of a "picoinjector" to add solution to flowing droplets [21,22] offers Segmented flow microfluidic devices offer an attractive means of studying crystallization processes. However, while they are widely employed for protein crystallization, there are few examples of their use for sparingly soluble compounds due to problems with rapid device fouling and irreproducibility over longer run-times. This article presents a microfluidic device which overcomes these issues, as this is constructed around a novel design of "picoinjector" that facilitates direct injection into flowing droplets. Exploiting a Venturi junction to ...

show abstract

Section: Discussionmentioning

confidence: 99%

Passive Picoinjection Enables Controlled Crystallization in a Droplet Microfluidic Device

Zeng

Gaule

et al. 2017

Small

View full text Add to dashboard Cite

show abstract

“…Te chniques such as time-resolved wide/ small-angle X-ray scattering [5] and light scattering [6] have been used to study the precipitation pathway of CaCO 3 in bulk solution while cryo-TEM has provided snapshots of its development. [7] LP-TEM has also been used to follow the precipitation of CaCO 3 in additive-free solutions, [8] and in the presence of PSS. [9] However,l ittle is known about the initial morphological development of calcite crystals in the presence of additives.T his study addresses this challenge by using a" Crystal Hotel" microfluidic device [10] as as imple and versatile means of investigating the morphological development of crystals.Each device provides an array of independent "rooms" with volumes of just 19 nL ( Figure 1) that not only slow down the rate of crystal growth, but also avoid the problems associated with impurities,i ncomplete mixing,a nd convection that are often found in bulk solution.…”

mentioning

confidence: 99%

The Effect of Additives on the Early Stages of Growth of Calcite Single Crystals

et al. 2017

View full text Add to dashboard Cite

As crystallization processes are often rapid, it can be difficult to monitor their growth mechanisms. In this study, we made use of the fact that crystallization proceeds more slowly in small volumes than in bulk solution to investigate the effects of the soluble additives Mg2+ and poly(styrene sulfonate) (PSS) on the early stages of growth of calcite crystals. Using a “Crystal Hotel” microfluidic device to provide well‐defined, nanoliter volumes, we observed that calcite crystals form via an amorphous precursor phase. Surprisingly, the first calcite crystals formed are perfect rhombohedra, and the soluble additives have no influence on the morphology until the crystals reach sizes of 0.1–0.5 μm for Mg2+ and 1–2 μm for PSS. The crystals then continue to grow to develop morphologies characteristic of these additives. These results can be rationalized by considering additive binding to kink sites, which is consistent with crystal growth by a classical mechanism.

show abstract

“…It becomes extremely challenging to in situ probe the hollowing process of colloidal nanoparticles in volatile liquids, which easily vaporize under the low pressure of EM operation to damage the microscopes. Benefiting from the significant advance in microfabrication and materials engineering, miniaturized cells have been successfully fabricated to place liquid dispersions of colloidal nanoparticles in TEM chambers for in situ study . A typical in situ TEM liquid cell is constructed with two electron‐transparent Si 3 N 4 films of < 100 nm in thickness, which are separated to provide a thin space (usually < 200 nm) to host the desired colloidal nanoparticle dispersions.…”

Section: In Situ Electron Microscopy Characterizationmentioning

confidence: 99%

“…Benefiting from the significant advance in microfabrication and materials engineering, miniaturized cells have been successfully fabricated to place liquid dispersions of colloidal nanoparticles in TEM chambers for in situ study. [53,[108][109][110][111][112] A typical in situ TEM liquid cell is constructed with two electrontransparent Si 3 N 4 films of < 100 nm in thickness, which are separated to provide a thin space (usually < 200 nm) to host the desired colloidal nanoparticle dispersions. The exceptional mechanical strength of the thin Si 3 N 4 films enables them to well seal the dispersion liquids in the high-vacuum TEM chambers.…”

Section: In Situ Electron Microscopy Characterizationmentioning

confidence: 99%

In Situ Techniques for Probing Kinetics and Mechanism of Hollowing Nanostructures through Direct Chemical Transformations

Sun

2018

Small Methods

View full text Add to dashboard Cite

Chemical transformation of nanostructures into hollow ones becomes important in the synthesis of materials with unique properties for applications ranging from sensing to energy storage, to high‐performance catalysis. The nanoscale Kirkendall effect and galvanic replacement represent two typical mechanisms responsible for hollowing nanostructures. These two mechanisms occur either independently or simultaneously to form hollow nanostructures with appropriate geometries and desirable properties. Precisely distinguishing the hollowing mechanism and kinetics involved in a chemical transformation relies on in situ characterization methods including in situ electron microscopy, in situ optical spectroscopy, and a suite of in situ synchrotron X‐ray techniques (e.g., imaging, scattering, and X‐ray absorption fine structure spectroscopy). Here, the two typical hollowing mechanisms and the in situ characterization extensively explored in recent years are summarized, providing a timely overview of the promise of in situ methods in studying nanoparticle evolution under real reaction conditions.

show abstract

Investigating materials formation with liquid-phase and cryogenic TEM

Cited by 174 publications

References 128 publications

Passive Picoinjection Enables Controlled Crystallization in a Droplet Microfluidic Device

Passive Picoinjection Enables Controlled Crystallization in a Droplet Microfluidic Device

The Effect of Additives on the Early Stages of Growth of Calcite Single Crystals

In Situ Techniques for Probing Kinetics and Mechanism of Hollowing Nanostructures through Direct Chemical Transformations

Contact Info

Product

Resources

About