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Conventional chemically amplified resists (CARs) rely on the usage of photoacid generators to serve as the source of chemical amplification. However, acid diffusion inevitably accompanies CARs and has led to the resolution, line edge roughness, and sensitivity (RLS) tradeoff, which is the most challenging technical problem for modern photoresists. Herein, we take advantage of the self-immolative property of polyphthalaldehyde (PPA) derivatives to create end-cap enabled chain scissionable resists for extreme ultraviolet (EUV) lithography. The feasibility of this strategy was demonstrated under UV photodegradation experiments. The dose-to-clear (DTC) under EUV radiation was 90 mJ/cm2 for the most promising resist, representing more than a hundredfold improvement over previous PPA resists. Density functional theory (DFT) calculations were conducted to understand the structural origin of end-cap EUV sensitivity.

Biofouling is a major disruptive process affecting the fuel efficiency and durability of maritime vessel coatings. Previous research has shown that amphiphilic coatings consisting of a siloxane backbone functionalized with hydrophilic moieties are effective marine antifouling and fouling-release materials. Poly(ethylene glycol) (PEG) has been the primary hydrophilic component used in such systems. Recently, the morpholine group has emerged as a promising compact alternative in antifouling membranes but is yet to be studied against marine foulants. In this work, the use of morpholine moieties to generate amphiphilicity in a poly(dimethylsiloxane) (PDMS)-based antifouling and fouling-release coating was explored. Two separate coating sets were investigated. The first set examined the incorporation of an N-substituted morpholine amine, and while these coatings showed promising fouling-release properties for

The buildup of organic matter and organisms on surfaces exposed to marine environments, known as biofouling, is a disruptive and costly process affecting maritime operations. Previous research has identified some of the surface characteristics particularly suited to the creation of antifouling and fouling-release surfaces, but there remains room for improvement against both macrofouling and microfouling organisms. Characterization of their adhesives has shown that many rely on oxidative chemistries. In this work, we explore the incorporation of the stable radical 2,2,6,6-tetramethylpipiderin-1-oxyl (TEMPO) as a component in an amphiphilic block copolymer system to act as an inhibitor for marine cements, disrupting adhesion of macrofouling organisms. Using polystyrene-b-poly(dimethylsiloxane-r-vinylmethysiloxane) block copolymers, pendent vinyl groups were functionalized with TEMPO and poly(ethylene glycol) to construct an amphiphilic material with redox active character. The antifouling and fouling-release performance of these materials was investigated through settlement and removal assays of three model fouling organisms and correlated to surface structure and chemistry. Surfaces showed significant antifouling character and fouling-release performance was increased substantially toward barnacles by the incorporation of stable radicals, indicating their potential for marine antifouling applications.

In this study of nanopatterned helical poly(benzyl-l-glutamate) (PBLG) brushes, rod-type brush arrays were fabricated via an integrated process of high-resolution lithography and surface-initiated vapor deposition polymerization (SI-VDP). "Nanospikes" of polymer brushes with spacings of less than 100 nm were produced. The topology and areal behavior of the resulting patterned rod-like brushes were analyzed and compared with patterned coil-type brushes. A geometric study of these self-assembled "nanospikes" was carried out, and their cross sections were investigated via focused ion beam (FIB) and scanning electron microscopy (SEM). Furthermore, the presence of poly(

Mixed polymer brushes of rod-type polypeptide and coil-type vinyl polymer brushes were synthesized via two sequential steps of vapor deposition surface-initiated ring-opening polymerization (SI-ROP) and surface-initiated atom transfer radical polymerization (SI-ATRP), respectively. The effect on polypeptide brushes by coil-type brushes of their surface morphology, film thickness, and orientation were investigated before and after solvent quenching processes using chloroform and acetone. Before solvent quenching, the as-grown coil-type brushes forced the polypeptide brushes to stand up from the surface, resulting in higher film thickness, but the polypeptide brushes remained randomly oriented. After solvent quenching, polypeptide brushes tended to aggregate into conical bundles with an orientation perpendicular to the substrate, but coil-type brushes restricted the free arrangement of the polypeptide brushes and lessen their upward movement. Changes in film thickness, rod orientation, morphology, and wettability were observed with increased molecular weight of the coil-type polymer in the mixed brushes.

This work represents a joint computational and experimental study on a series of

As increasingly smaller molecular materials and material structures are devised or developed for technological applications, the demands on the processes of lithography now routinely include feature sizes that are of the order of 10 nm. In reaching such a fine level of resolution, the methods of lithography have increased markedly in sophistication and brought into play 2terminology that is unfamiliar, on the one hand, to scientists tasked with the development of new lithographic materials or, on the other, to the engineers who design and operate the complex equipment that is required in modern-day processing. Publications produced by scientists need to be understood by engineers and vice versa, and these commonly arise from collaborative research that draws heavily on the terminology of two or more of the traditional disciplines. It is developments in polymer science and material science that lead progress in areas that cross traditional boundaries, such as microlithography. This document provides the exact definitions of a selection of unfamiliar terms that researchers and practitioners from different disciplines might encounter.

This work represents a joint computational and experimental study on a series of n-ethylene glycol (PEOn)-terminated quaterthiophene (4T) oligomers for 1 < n < 10 to elucidate their self-assembly b...

Macromolecular radicals are receiving growing interest as functional materials in energy storage devices and in electronics. With the need for enhanced conductivity, researchers have turned to macromolecular radicals bearing conjugated backbones, but results thus far have yielded conjugated radical polymers that are inferior in comparison to their non-conjugated partners. The emerging explanation is that the radical unit and the conjugated backbone (both being redox active) transfer electrons between each other, essentially “quenching” conductivity or capacity. Here, the internal charge transfer process is quantified using a polythiophene loaded with 0, 25, or 100% nitroxide radicals (2,2,6,6-tetramethyl-1-piperidinyloxy [TEMPO]). Importantly, deconvolution of the cyclic voltammograms shows mixed faradaic and non-faradaic contributions that contribute to the internal charge transfer process. Further, mixed ion-electron transfer is determined for the 100% TEMPO-loaded conjugated radical polymer, from which it is estimated that one triflate anion and one propylene carbone molecule are exchanged for every electron. Although these findings indicate the reason behind their poor conductivity and capacity, they point to how these materials might be used as voltage regulators in the future., Conjugated radical polymers can exhibit internal electron transfer depending on the radical loading.

Polymers are commonly used in applications that require long-term exposure to water and aqueous mixtures, serving as water purification membranes, marine antifouling coatings, and medical implants, among many other applications. Because polymer surfaces restructure in response to the surrounding environment

Concurrent advances in the programmable synthesis of nanostructured materials and additive three-dimensional (3D) manufacturing have created a rich and exciting opportunity space to fabricate novel...

Hafnium dioxide (HfO2) and zirconium dioxide (ZrO2) nanoparticles (NPs) have gained attention as components of photoresists for next-generation photolithography. Coating of these NPs with organic ligands has been shown to increase their efficiency in photolithography. This study evaluated the microbial toxicity of hafnium dioxide and zirconium dioxide NPs coated with benzoate, isobutyrate or methacrylate toward heterotrophic aerobes, methanogens and the bioluminescent bacterium Aliivibrio fischeri. The stability of NPs in the media was assessed as a function of zeta potential, particle size distribution and leaching analyses. NP dispersions were unstable in all bioassay media, resulting in particle aggregation and settling. Leaching tests showed that dissolution of the organic ligands from the NPs varied widely depending on the nanomaterial and medium considered. The NPs were harmless to aerobic heterotrophs and methanogens at high concentrations (800–1200 mg/l). In contrast, they displayed low to moderate toxicity to A. fischeri (50% inhibition at 286–1372 mg/l), with benzoate-coated NPs causing the highest inhibition. Further analyses confirmed that the inhibition observed in assays with A. fischeri should be attributed to the coated NPs rather than to the dissolved organic ligands. Overall, the NP photoresists tested in this study are unlikely to exert acute microbial toxicity at environmentally relevant concentrations (sub-parts-per-million levels).

Developing soft materials with both ion and electron transport functionalities is of broad interest for energy-storage and bioelectronics applications. Rational design of these materials requires a fundamental understanding of interactions between ion and electron conducting blocks along with the correlation between the microstructure and the conduction characteristics. Here, we investigate the structure and mixed ionic/electronic conduction in thin films of a liquid crystal (LC) 4T/PEO4, which consists of an electronically conducting quarterthiophene (4T) block terminated at both ends by ionically conducting oligoethylenoxide (PEO4) blocks. Using a combined experimental and simulation approach, 4T/PEO4 is shown to self-assemble into smectic, ordered, or disordered phases upon blending the materials with the ionic dopant bis(trifluoromethane)sulfonimide lithium (LiTFSI) under different LiTFSI concentrations. Interestingly, at intermediate LiTFSI concentration, ordered 4T/PEO4 exhibits an electronic conductivity as high as 3.1 × 10-3 S/cm upon being infiltrated with vapor of the 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) molecular dopant while still maintaining its ionic conducting functionality. This electronic conductivity is superior by an order of magnitude to the previously reported electronic conductivity of vapor co-deposited 4T/F4TCNQ blends. Our findings demonstrate that structure and electronic transport in mixed conduction materials could be modulated by the presence of the ion transporting component and will have important implications for other more complex mixed ionic/electronic conductors.

In marine industries, the accumulation of organic matter and marine organisms on ship hulls and instruments limits performance, requiring frequent maintenance and increasing fuel costs. Current coatings technology to combat this biofouling relies heavily on the use of toxic, biocide-containing paints. These pose a serious threat to marine ecosystems, affecting both target and nontarget organisms. Innovation in the design of polymers offers an excellent platform for the development of alternatives, but the creation of a broad-spectrum, nontoxic material still poses quite a hurdle for researchers. Surface chemistry, physical properties, durability, and attachment scheme have been shown to play a vital role in the construction of a successful coating. This review explores why these characteristics are important and how recent research accounts for them in the design and synthesis of new environmentally benign antifouling and fouling release materials.

The benefits of incorporating amphiphilic properties into antifouling and fouling-release coatings are well-established. The use of sequence-defined peptides and peptoids in these coatings allows p...

We report a facile synthetic approach to create stable radical block copolymers containing a secondary fluorinated block via anionic polymerization using a bulky, sterically hindered countercation composed of a sodium ion and di-benzo-18-crown-6 complex. The synthetic conditions described in this report allowed for controlled molecular weights and dispersity (

Nitroxide-functional polymers have garnered considerable interest in recent years and appear to hold promise for energy storage applications. However, their synthesis can be both expensive and time-consuming. Here, we propose a highly convenient method for the preparation of TEMPO-functional diblock copolymer nanoparticles directly in water. Epoxy-functional diblock copolymer worms are synthesized from a single monomer, glycidyl methacrylate (GlyMA), using a three-step, one-pot protocol in aqueous solution via polymerization-induced self-assembly (PISA). First, an initial aqueous emulsion of GlyMA was heated at 85 °C for 9 h to afford an aqueous solution of glycerol monomethacrylate (GMA). Then reversible addition–fragmentation chain transfer (RAFT) polymerization of GMA was conducted in aqueous solution using a dicarboxylic acid-based RAFT agent to produce a water-soluble PGMA homopolymer. Finally, chain extension of this precursor block via RAFT aqueous emulsion polymerization of GlyMA at 50 °C produced amphiphilic diblock copolymer chains that self-assembled in situ to form a 15% w/w aqueous dispersion of diblock copolymer worms. These worms can be derivatized directly using 4-amino-TEMPO in aqueous solution, affording novel crosslinked anisotropic nanoparticles that contain a relatively high density of stable nitroxide radicals for potential charge storage applications.

Thin-film composite (TFC) polyamide reverse osmosis (RO) membranes are prone to biofouling due to their inherent physicochemical surface properties. In order to address the biofouling problem, we have developed novel surface coatings functionalized with biocidal silver nanoparticles (AgNPs) and antifouling polymer brushes via polyelectrolyte layer-by-layer (LBL) self-assembly. The novel surface coating was prepared with polyelectrolyte LBL films containing poly(acrylic acid) (PAA) and poly(ethylene imine) (PEI), with the latter being either pure PEI or silver nanoparticles coated with PEI (Ag–PEI). The coatings were further functionalized by grafting of polymer brushes, using either hydrophilic poly(sulfobetaine) or low surface energy poly(dimethylsiloxane) (PDMS). The presence of both LBL films and sulfobetaine polymer brushes at the interface significantly increased the hydrophilicity of the membrane surface, while PDMS brushes lowered the membrane surface energy. Overall, all surface modifications resulted in significant reduction of irreversible bacterial cell adhesion. In microbial adhesion tests with E. coli bacteria, a normalized cell adhesion in the range of only 4 to 16% on the modified membrane surfaces was observed. Modified surfaces containing silver nanoparticles also exhibited strong antimicrobial activity. Membranes coated with LBL films of PAA/Ag–PEI achieved over 95% inactivation of bacteria attached to the surface within 1 hour of contact time. Both the antifouling and antimicrobial results suggest the potential of using these novel surface coatings in controlling the fouling of RO membranes.

This chapter will focus on materials strategies for 2-photon, 3D patterning materials. Considering that the patterning process and the 2-photon sensitive photoactive materials are already well discussed, they will only be mentioned briefly when important and this chapter will focus on the polymers and oligomers that are patterned. This chapter will summarize progress in the development of hard materials systems and include mention of filled systems. It will also focus in particular on new softer materials such as elastomers and hydrogels. Applications of these materials will be described briefly as part of each materials section. The review is intended to give an overview of the many different kinds of 3D photopatternable materials that have been successfully processed using 2-photon lithography, but it is not intended to be an exhaustive compilation of materials systems.

We report the formation of robust, reproducible, pinhole-free, thin layers of fluorinated polyfluorene conjugated copolymers on a range of polymeric underlayers via a simple solution processing method. This is driven by the different characters of the fluorinated and nonfluorinated sections of these polymers. Photothermal deflection spectroscopy is used to determine that these layers are 1-2 nm thick, corresponding to a molecularly thin layer. Evidence that these layers are continuous and pinhole-free is provided by electroluminescence data from polymer LED devices that incorporate these layers within the stacked LED structure. These reveal, remarkably, light emission solely from these molecularly thin layers.

Research on engineered nanomaterials (ENM) has progressed rapidly from the very early stages of studying their unique, size-dependent physicochemical properties and commercial exploration to the development of products that influence our everyday lives. We have previously reviewed various methods for synthesis, surface functionalization, and analytical characterization of ENM in a publication titled ‘Engineered Nanomaterials: Preparation, Functionalization and Characterization’. In this second, inter-linked document, we first provide an overview of important applications of ENM in products relevant to human healthcare and consumer goods, such as food, textiles, and cosmetics. We then highlight the challenges for the design and development of new ENM for bio-applications, particularly in the rapidly developing nanomedicine sector. The second part of this document is dedicated to nanotoxicology studies of ENM in consumer products. We describe the various biological targets where toxicity may occur, summarize the four nanotoxicology principles, and discuss the need for careful consideration of the biodistribution, degradation, and elimination routes of nanosized materials before they can be safely used. Finally, we review expert opinions on the risk, regulation, and ethical aspects of using engineered nanomaterials in applications that may have direct or indirect impact on human health or our environment.

The World Chemistry Leadership Meeting (WCLM) is an integral part of the IUPAC General Assembly and offers a platform for representatives from National Adhering Organizations (NAOs) to meet and discuss emerging and pressing issues of global concern. Recent WCLMs have had a special focus on Young Observers (YOs) to provide them with the space to interact and discuss emerging issues and future challenges facing the world of chemistry.

Synthesizing a stable radical polymer with a conjugated backbone seems like a natural way to introduce conductivity to radical polymers, which are traditionally synthesized with insulating, nonconjugated backbones. For charge storage applications that take advantage of the redox-active nature of stable radical polymers, enhanced conductivity would improve performance. To explore the interplay between stable radicals and a conjugated backbone, we prepared and studied soluble polythiophene with high regioregularity and various concentrations of pendent radical groups to systematically examine any change in conductivity with radical incorporation. Using electron paramagnetic resonance and electrical conductivity measurements, we show that there is an exponential decrease in conductivity as we increase the percentage of pendent groups attached to repeating units, which changes the conductivity by 6 orders of magnitude between the nonradical control polythiophene material and the material with the highest radi...

We report the preparation of discrete nanometer-scale zinc-based clusters and use them to form sub-15 nm structures by means of extreme ultraviolet lithography. By taking advantage of a metal-containing building unit derived by a metal–organic framework—MOF-2, we found the 3-methyl-phenyl-modified Zn-mTA cluster that formed is well-defined with controlled size and structure and demonstrates extremely high solubility. Progress in recent years in metal–organic frameworks has created a rich variety of metal-containing structures that are useful for numerous applications. Substitution of the bridging ligands with monovalent ligands produces a discrete metal–organic cluster that strongly interacts with soft X-rays at a wavelength of 13 nm. Here we describe the design, preparation, computational modeling, and physical characterization of these new materials. Such metal-containing structures may form the basis of photoresists that enable the next generation of microelectronic devices.

A new emulsion polymerization based on Activators Regenerated by Electron Transfer Atom Transfer Radical Polymerization (ARGET ATRP) has been developed to produce poly(methyl methacrylate) (PMMA). The critical components of single-pot synthesis via a mini Monomer Encapsulated ARGET ATRP emulsion polymerization will be discussed. In this method, monomer is isolated in a micelle by pre-emulsification in a nonionic surfactant through high power stirring while acetone is introduced to the polymerization to aid in reactant transport and tetrabutylammonium salts are used as phase transfer agents. Polymerizations using tetrabutylammonium bromide (TBAB) were more controlled and demonstrated low Đ (Mw/Mn 1.50). First-order linear kinetics for MMA polymerizations at 100 mM TBAB was demonstrated, while the reactions deviated from linearity at higher concentrations of TBAB and all concentrations of TBAC.

Incorporating natural product antifoulants (NPAs) into coatings with controlled surface topography is considered a promising way to suppress marine fouling. However, the rapid leakage of NPAs and the relatively complicated process of constructing well-patterned topography remain unresolved problems for practical applications. In this work, capsaicin bonded to CoFe2O4/gelatin magnetic nanoparticles was mixed with a polydimethylsiloxane (PDMS)-based block copolymer. When applied together by a simple spray-coating method, these materials formed a film. The leakage of capsaicin was restrained by the chemical bonds with the CoFe2O4/gelatin nanospheres. The primary nanorough structure was constructed by the phase separation of the PDMS-based copolymer. The secondary nanorough structure was formed by the incorporation of capsaicin-loaded CoFe2O4/gelatin nanospheres, which were demonstrated to improve the orientation of the PDMS-based block copolymer chains. The combination of oriented nanotopography and nonleaki...