Electrospinning is a versatile and viable technique for generating ultrathin fibers. Remarkable progress has been made with regard to the development of electrospinning methods and engineering of electrospun nanofibers to suit or enable various applications. We aim to provide a comprehensive overview of electrospinning, including the principle, methods, materials, and applications. We begin with a brief introduction to the early history of electrospinning, followed by discussion of its principle and typical apparatus. We then discuss its renaissance over the past two decades as a powerful technology for the production of nanofibers with diversified compositions, structures, and properties. Afterward, we discuss the applications of electrospun nanofibers, including their use as "smart" mats, filtration membranes, catalytic supports, energy harvesting/conversion/storage components, and photonic and electronic devices, as well as biomedical scaffolds. We highlight the most relevant and recent advances related to the applications of electrospun nanofibers by focusing on the most representative examples. We also offer perspectives on the challenges, opportunities, and new directions for future development. At the end, we discuss approaches to the scale-up production of electrospun nanofibers and briefly discuss various types of commercial products based on electrospun nanofibers that have found widespread use in our everyday life.

Electrospinning and Electrospun Nanofibers: Methods, Materials, and Applications

Capillarity and Wetting Phenomena: Drops, Bubbles, Pearls, Waves

With the arising of global climate change and resource shortage, in recent years, increased attention has been paid to environmentally friendly materials. Trees are sustainable and renewable materials, which give us shelter and oxygen and remove carbon dioxide from the atmosphere. Trees are a primary resource that human society depends upon every day, for example, homes, heating, furniture, and aircraft. Wood from trees gives us paper, cardboard, and medical supplies, thus impacting our homes, school, work, and play. All of the above-mentioned applications have been well developed over the past thousands of years. However, trees and wood have much more to offer us as advanced materials, impacting emerging high-tech fields, such as bioengineering, flexible electronics, and clean energy. Wood naturally has a hierarchical structure, composed of well-oriented microfibers and tracheids for water, ion, and oxygen transportation during metabolism. At higher magnification, the walls of fiber cells have an interes...

https://www.fpl.fs.fed.us/documnts/pdf2016/fpl_2016_zhu001.pdf

Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications.

This review collects recent developments in the field of liquid crystalline elastomers (LCEs) with an emphasis on their use for actuator and sensor applications. Several synthetic pathways leading to crosslinked liquid crystalline polymers are discussed and how these materials can be oriented into liquid crystalline monodomains are described. By comparing the actuating properties of different systems, general structure-property relationships for LCEs are obtained. In the final section, how these materials can be turned into usable devices using different interdisciplinary techniques are described.

Liquid Crystalline Elastomers as Actuators and Sensors

An overview on the recent developments in the field of liquid crystalline bent-core molecules (so-called banana liquid crystals) is given. After some basic issues, dealing with general aspects of the systematisation of the mesophases, development of polar order and chirality in this class of LC systems and explaining some general structure–property relationships, we focus on fascinating new developments in this field, such as modulated, undulated and columnar phases, so-called B7 phases, phase biaxiality, ferroelectric and antiferroelectric polar order in smectic and columnar phases, amplification and switching of chirality and the spontaneous formation of superstructural and supramolecular chirality.

/pdf/bent-core-liquid-crystals-polar-order-superstructural-17m3bst2sc.pdf

Bent-core liquid crystals: polar order, superstructural chirality and spontaneous desymmetrisation in soft matter systems

Cellulose nanocrystals (CNCs), produced by the acid hydrolysis of wood, cotton or other cellulose-rich sources, constitute a renewable nanosized raw material with a broad range of envisaged uses: f ...

/pdf/cellulose-nanocrystal-based-materials-from-liquid-crystal-396tyw1257.pdf

Cellulose nanocrystal-based materials: from liquid crystal self-assembly and glass formation to multifunctional thin films

https://orbilu.uni.lu/bitstream/10993/20503/1/Lagerwall%20%26%20Scalia%202012.pdf

A new era for liquid crystal research: Applications of liquid crystals in soft matter nano-, bio- and microtechnology

Interest in the smectic liquid-crystalline state of matter received a substantial boost with the discovery by Meyer in the mid-1970s that a chiral smectic C (SmC*) phase exhibits a spontaneous electric polarization, and with the subsequent demonstration by Clark and Lagerwall of the surface-stabilized SmC* ferroelectric liquid crystal at the beginning of the 1980s. Since then, chiral smectic phases and their plethora of polar effects have dominated the research in this field, which today has reached a mature state where the first commercial microdisplay applications are now shipping in millions-per-year quantities. In this Review we discuss some of the topics of highest interest in current smectic liquid crystal research, and address application-relevant research (de Vries-type tilting transitions without defect generation and high-tilt antiferroelectric liquid crystals with perfect dark state) as well as more curiosity-driven research (the nature and origin of the chiral smectic C subphases and their intermediate frustrated states between ferro- and antiferroelectricity).

Current topics in smectic liquid crystal research.

We review the research on carbon nanotube (CNT) dispersion in liquid crystals (LCs), focusing mainly on the approaches where the aim is to align CNTs along the LC director field, but also covering briefly the proposed possibility to enhance thermotropic LCs by CNT doping All relevant LC types are considered: thermotropic LC hosts allowing dynamic CNT realignment, lyotropic LC hosts allowing very high concentration of CNTs uniformly aligned over macroscopic areas and consequent removal of the LC, and LC phases formed by CNTs themselves, used in spinning high-quality carbon nanotube fibres We also discuss the issue of CNT dispersion in some detail, since successful nanotube separation is imperative for success in this field regardless of the type of LC that is considered We end by defining a few major challenges for the development of the field over the next few years, critical for reaching the stage where industrially viable protocols for LC-based CNT alignment can be defined

/pdf/carbon-nanotubes-in-liquid-crystals-4fj7i5je7i.pdf

Carbon nanotubes in liquid crystals

A new method for the successful alignment of carbon nanotubes is presented. An aqueous lyotropic nematic liquid-crystal phase acts as a self-organizing template to align and disperse the nonfunctionalized nanotubes simultaneously, and the success of the method is confirmed through Raman spectroscopy analysis (see figure). This work could be extended to allow tailoring of the alignment for specific purposes and properties, using different lyotropic liquid crystals.

Jan P. F. Lagerwall

Papers

Cellulose nanocrystal-based materials: from liquid crystal self-assembly and glass formation to multifunctional thin films

A new era for liquid crystal research: Applications of liquid crystals in soft matter nano-, bio- and microtechnology

Current topics in smectic liquid crystal research.

Carbon nanotubes in liquid crystals

Nanotube Alignment Using Lyotropic Liquid Crystals