Editing Soft matter (section)

== Experimental characterization ==
Due to the importance of mesoscale structures in the overarching properties of soft matter, experimental work is primarily focused on the bulk properties of the materials. Rheology is often used to investigate the physical changes of the material under stress.<ref name=":3" /> Biological systems, such as protein crystallization, are often investigated through [[X-ray crystallography|X-ray]] and [[neutron crystallography]],<ref name=":18">{{Cite journal |last1=Fusco |first1=Diana |last2=Charbonneau |first2=Patrick |date=2016 |title=Soft matter perspective on protein crystal assembly |url=https://linkinghub.elsevier.com/retrieve/pii/S0927776515300576 |journal=Colloids and Surfaces B: Biointerfaces |language=en |volume=137 |pages=22–31 |doi=10.1016/j.colsurfb.2015.07.023|pmid=26236019 |s2cid=13969559 |arxiv=1505.05214 }}</ref> while [[nuclear magnetic resonance spectroscopy]] can be used in understanding the average structure and lipid mobility of membranes.<ref name=":17" />

=== Scattering ===
{{Main|Scattering}}
[[Scattering]] techniques, such as [[wide-angle X-ray scattering]], [[small-angle X-ray scattering]], [[neutron scattering]], and [[dynamic light scattering]] can also be used for materials when probing for the average properties of the constituents. These methods can determine [[particle-size distribution]], shape, [[crystallinity]] and [[diffusion]] of the constituents in the system.<ref name=":19">{{Cite journal |last=Scheffold |first=Frank |date=2020-09-04 |title=Pathways and challenges towards a complete characterization of microgels |journal=Nature Communications |language=en |volume=11 |issue=1 |pages=4315 |doi=10.1038/s41467-020-17774-5 |issn=2041-1723 |pmc=7473851 |pmid=32887886|bibcode=2020NatCo..11.4315S }}</ref><ref>{{Cite journal |last1=Murthy |first1=N.S. |last2=Minor |first2=H. |date=1990 |title=General procedure for evaluating amorphous scattering and crystallinity from X-ray diffraction scans of semicrystalline polymers |url=https://linkinghub.elsevier.com/retrieve/pii/003238619090243R |journal=Polymer |language=en |volume=31 |issue=6 |pages=996–1002 |doi=10.1016/0032-3861(90)90243-R}}</ref> There are limitations in the application of scattering techniques to some systems, as they can be more suited to [[Isotropy|isotropic]] and dilute samples.<ref name=":19" />

=== Computational ===
{{Main|Computer simulation}}
[[Computational chemistry|Computational]] methods are often employed to model and understand soft matter systems, as they have the ability to strictly control the composition and environment of the structures being investigated, as well as span from microscopic to macroscopic length scales.<ref name=":5" /> Computational methods are limited, however, by their suitability to the system and must be regularly validated against experimental results to ensure accuracy.<ref name=":5" /> The use of [[informatics]] in the prediction of soft matter properties is also a growing field in computer science thanks to the large amount of data available for soft matter systems.<ref>{{Cite journal |last1=Peerless |first1=James S. |last2=Milliken |first2=Nina J. B. |last3=Oweida |first3=Thomas J. |last4=Manning |first4=Matthew D. |last5=Yingling |first5=Yaroslava G. |date=2019 |title=Soft Matter Informatics: Current Progress and Challenges |journal=Advanced Theory and Simulations |language=en |volume=2 |issue=1 |pages=1800129 |doi=10.1002/adts.201800129 |s2cid=139778116 |issn=2513-0390|doi-access=free }}</ref>

=== Microscopy ===
{{Main|Microscopy}}
[[Optical microscope|Optical microscopy]] can be used in the study of colloidal systems, but more advanced methods like [[transmission electron microscopy]] (TEM) and [[atomic force microscopy]] (AFM) are often used to characterize forms of soft matter due to their applicability to mapping systems at the nanoscale.<ref>Wu, H.,  Friedrich, H.,  Patterson, J. P.,  Sommerdijk, N. A. J. M.,  de, N. (2020), "Liquid-Phase Electron Microscopy for Soft Matter Science and Biology". ''Adv. Mater.'' '''32''', 2001582. {{doi|10.1002/adma.202001582}}</ref><ref>{{Cite journal |last=Garcia |first=Ricardo |date=2020-08-17 |title=Nanomechanical mapping of soft materials with the atomic force microscope: methods, theory and applications |journal=Chemical Society Reviews |language=en |volume=49 |issue=16 |pages=5850–5884 |doi=10.1039/D0CS00318B |pmid=32662499 |s2cid=220519766 |issn=1460-4744|doi-access=free }}</ref> These imaging techniques are not universally appropriate to all classes of soft matter and some systems may be more suited to one kind of analysis than another. For example, there are limited applications in imaging hydrogels with TEM due to the processes required for imaging. However, [[Fluorescence microscope|fluorescence microscopy]] can be readily applied.<ref name=":19" /> Liquid crystals are often probed using [[polarized light microscopy]] to determine the ordering of the material under various conditions, such as [[temperature]] or [[electric field]].<ref>{{Cite journal |last1=Miller |first1=Daniel S. |last2=Carlton |first2=Rebecca J. |last3=Mushenheim |first3=Peter C. |last4=Abbott |first4=Nicholas L. |date=2013-03-12 |title=Introduction to Optical Methods for Characterizing Liquid Crystals at Interfaces |journal=Langmuir |language=en |volume=29 |issue=10 |pages=3154–3169 |doi=10.1021/la304679f |pmid=23347378 |pmc=3711186 |issn=0743-7463}}</ref>