Thin film deposition techniques for polymeric membranes– A review

The global society is in a transition, where dealing with climate change and water scarcity are important challenges. More efficient separations of chemical species are essential to reduce energy consumption and to provide more reliable access to clean water. Here, membranes with advanced functionalities that go beyond standard separation properties can play a key role. This includes relevant functionalities, such as stimuli-responsiveness, fouling control, stability, specific selectivity, sustainability, and antimicrobial activity. Polyelectrolytes and their complexes are an especially promising system to provide advanced membrane functionalities. Here, we have reviewed recent work where advanced membrane properties stem directly from the material properties provided by polyelectrolytes. This work highlights the versatility of polyelectrolyte-based membrane modifications, where polyelectrolytes are not only applied as single layers, including brushes, but also as more complex polyelectrolyte multilayers on both porous membrane supports and dense membranes. Moreover, free-standing membranes can also be produced completely from aqueous polyelectrolyte solutions allowing much more sustainable approaches to membrane fabrication. The Review demonstrates the promise that polyelectrolytes and their complexes hold for next-generation membranes with advanced properties, while it also provides a clear outlook on the future of this promising field.

Polyelectrolytes as Building Blocks for Next-Generation Membranes with Advanced Functionalities.

Roll-to roll initiated chemical vapor deposition of super hydrophobic thin films on large-scale flexible substrates

Originally regarded as auxiliary additives, nanoparticles have become important constituents of polyelectrolyte multilayers. They represent the key components to enhance mechanical properties, enable activation by laser light or ultrasound, construct anisotropic and multicompartment structures, and facilitate the development of novel sensors and movable particles. Here, we discuss an increasingly important role of inorganic nanoparticles in the layer-by-layer assembly—effectively leading to the construction of the so-called hybrid coatings. The principles of assembly are discussed together with the properties of nanoparticles and layer-by-layer polymeric assembly essential in building hybrid coatings. Applications and emerging trends in development of such novel materials are also identified.

https://www.mdpi.com/2079-6412/10/11/1131/pdf

Nanoparticles in polyelectrolyte multilayer layer-by-layer (LbL) films and capsules : key enabling components of hybrid coatings

Biodegradable or transient electronics is an emerging technology whose key characteristic is an ability to dissolve, resorb, physically disappear or disintegrate in physiological environments after fulfilling their functions over prescribed time frames. Biodegradable electronics as temporary implants can be safely absorbed by the body, and as green electronics can effectively alleviate landfill and environmental issues caused by electronic wastes, which are expected to ultimately eliminate associated costs and risks resulting from recycling operations. In this review, the state of the art of the biodegradable polymers, their fabrication techniques, and potential applications in environment friendly electronic skins (e-skins) are comprehensively summarized and systematically discussed. In addition, the future outlook for the development of biodegradable e-skins is also discussed at the end. It is expected that this review will potentially provide vital tools and beneficial strategies for the design of biodegradable e-skins with the functions of diagnosis, therapy and green sensing that are beneficial for human healthcare and environmental protection.

A review on emerging biodegradable polymers for environmentally benign transient electronic skins

Deposition of polymer films by spin casting: A quantitative analysis

Automated synthesis of DNA, RNA, and peptides provides quickly and reliably important tools for biomedical research. Automated glycan assembly (AGA) is significantly more challenging, as highly branched carbohydrates require strict regio- and stereocontrol during synthesis. A new AGA synthesizer enables rapid temperature adjustment from -40 to +100 °C to control glycosylations at low temperature and accelerates capping, protecting group removal, and glycan modifications using elevated temperatures. Thereby, the temporary protecting group portfolio is extended from two to four orthogonal groups that give rise to oligosaccharides with up to four branches. In addition, sulfated glycans and unprotected glycans can be prepared. The new design reduces the typical coupling cycles from 100 to 60 min while expanding the range of accessible glycans. The instrument drastically shortens and generalizes the synthesis of carbohydrates for use in biomedical and material science.

/pdf/microwave-assisted-automated-glycan-assembly-2bapiurc8g.pdf

Microwave-Assisted Automated Glycan Assembly.

The deposition of nanosize and microsize spherical particles on planar solid substrates by hydrodynamic-evaporative spin-casting is studied. The particles are dispersed in a volatile liquid, which ...

Controlled Deposition of Nanosize and Microsize Particles by Spin-Casting

Abstract Glycosidic bond formation is a continual challenge for practitioners. Aiming to enhance the reproducibility and efficiency of oligosaccharide synthesis, we studied the relationship between glycosyl donor activation and reaction temperature. A novel semi‐automated assay revealed diverse responses of members of a panel of thioglycosides to activation at various temperatures. The patterns of protecting groups and the thiol aglycon combine to cause remarkable differences in temperature sensitivity among glycosyl donor building blocks. We introduce the concept of donor activation temperature to capture experimental insights, reasoning that glycosylations performed below this reference temperature evade deleterious side reactions. Activation temperatures enable a simplified temperature treatment and facilitate optimization of glycosyl donor usage. Isothermal glycosylation below the activation temperature halved the equivalents of building block required in comparison to the standard “ramp” regime used in solution‐ and solid‐phase oligosaccharide synthesis to‐date.

Towards a Systematic Understanding of the Influence of Temperature on Glycosylation Reactions

https://pubs.acs.org/doi/pdf/10.1021/acs.orglett.0c01264

José Angél Danglad-Flores

Papers

Deposition of polymer films by spin casting: A quantitative analysis

Microwave-Assisted Automated Glycan Assembly.

Controlled Deposition of Nanosize and Microsize Particles by Spin-Casting

Towards a Systematic Understanding of the Influence of Temperature on Glycosylation Reactions

Automated Glycan Assembly in a Variable-Bed Flow Reactor Provides Insights into Oligosaccharide-Resin Interactions.