Low cost, controlled crystallinity, chemical, and mechanical stability enable application of polymers in energy, water, electronics, and biomedical industries. Recent studies have shown that tailoring surface properties of polymers impacts their durability and functionality in these applications. However, the functionality and performance of polymer‐based devices and systems are greatly affected by the modification method and the process parameters, highlighting the need for understanding these methods and their mechanisms of operation in detail. The selection of the modification method invariably decides the properties enhanced in the polymer. In this review, various polymer surface modification treatments are discussed. These methods are categorized into physical, chemical, thermal, and optical ways, while illustrating their advantages and disadvantages. This review also explores the surface modification of polymers by patterning which encompasses one or more surface treatment methods. An application‐oriented study is presented discussing the relative importance of a method pertaining to a specific field of end‐application.

Deep eutectic solvents (DESs) are an emerging class of non-aqueous solvents that are potentially scalable, easy to prepare and functionalize for many applications ranging from biomass processing to energy storage technologies. Predictive understanding of the fundamental correlations between local structure and macroscopic properties is needed to exploit the large design space and tunability of DESs for specific applications. Here, we employ a range of computational and experimental techniques that span length-scales from molecular to macroscopic and timescales from picoseconds to seconds to study the evolution of structure and dynamics in model DESs, namely Glyceline and Ethaline, starting from the parent compounds. We show that systematic addition of choline chloride leads to microscopic heterogeneities that alter the primary structural relaxation in glycerol and ethylene glycol and result in new dynamic modes that are strongly correlated to the macroscopic properties of the DES formed.

Liquid-like Nanoscale Organic Hybrid Materials or NOHMs consisting of polymer grafted nanoparticles have shown great promise in applications, such as electrochemistry and gas separation, due to their enhanced conductivity, tunability, and negligible vapor pressure. Recently, NOHMs are considered to be used as novel electrolytes in Redox Flow Batteries (RFBs). However, to employ NOHMs in redox flow batteries as electrolytes, it is important to understand the conformation and dispersion of NOHMs in the electrochemical milieu. Here, we report the use of small-angle neutron scattering to probe the structure and dispersion of Jeffamine M2070 polymer grafted to a SiO 2 nanoparticle in an aqueous solution with and without the presence of a supporting electrolyte. Our results indicate that, in the aqueous environment, there exists a large amount of free polymer in the solution that is not grafted to the functionalized nanoparticles. These protonated free polymers, dispersed in the aqueous solvent, may also strongly interact with the grafted polymer layer and greatly affect the neat structure of NOHMs. Thus, there also exist polymers identified as "interacting" polymers to distinguish them from tethered or truly free polymers in the fluid system. The presence of supporting electrolyte shows a greater effect on the structure of NOHMs-based fluid as it not only alters the structure of the free polymer but also hinders the interaction of the polymer with the functionalized nanoparticles. Moreover, the change in the interaction of the Jeffamine M2070 with the functionalized nanoparticles due to the addition of supporting electrolyte has revealed a drastic change in the viscosities of NOHM solutions. Overall, the dispersion of the free polymer, the interaction of the interacting polymer with grafted polymer, and the change in conformation of free polymer and grafted layers with the addition of supporting electrolyte provide valuable insight into the overall scenario of the electrochemical environment of NOHMs. These results can be applied to fine-tune the structure of liquid-like NOHMs and will aid in a better understanding of their performance as potential electrolytes in RFBs.

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Nanoscale Organic Hybrid Materials (NOHMs) consist of polymers tethered to a nanoparticle surface, and NOHMs formed with an ionic bond between the polymer and nanoparticle have been proposed for electrochemical applications. NOHMs exhibit negligible vapor pressure, chemical tunability, oxidative thermal stability, and high ionic conductivity making them attractive in reactive and separation systems. In this study, NOHMs are synthesized by tethering Jeffamine M2070 (HPE) to SiO 2 nanocores via ionic (NOHM-I-HPE) and covalent (NOHM-C-HPE) bonding to investigate the effect of the bond type on the thermal, structural and transport properties of the tethered HPE. In the neat state, NOHM-C-HPE displays the highest thermal stability in a nitrogen atmosphere, while NOHM-I-HPE is the most stable under oxidative conditions. Small-angle neutron scattering (SANS) reveals the presence of multiple types of HPE polymers in aqueous solutions of NOHM-I-HPE (i.e., tethered, interacting, and free), whereas only tethered HPE is observed in NOHM-C-HPE systems. Moreover, the SANS profiles identify clustering of NOHM-C-HPE in aqueous solutions, but not in the corresponding NOHM-I-HPE solutions, suggesting that the free HPE chains stabilize the dispersion of NOHM-I-HPE. The results of this study elucidate how the bond type and grafting density can be used to tune the properties of NOHMs.

A novel hexahedron fiber has been proposed for biomedical imaging applications and efficient guiding of terahertz radiation. A finite element method (FEM) has been applied to investigate the guiding properties rigorously. All numerically computational investigated results for optimum parameters have revealed the high numerical aperture (NA) of 0.52, high core power fraction of 64%, near zero flattened dispersion of 0.5 ± 0.6 ps/THz/cm over the 0.8–1.4 THz band and low losses with 80% of the bulk absorption material loss. In addition, the V–parameter is also inspected for checking the proposed fiber modality. The proposed single-mode hexahedron photonic crystal fiber (PCF) can be highly applicable for convenient broadband transmission and numerous applications in THz technology.

Conformal coating of cylindrically‐patterned carbon nano tube micropillars with a dielectric poly‐tetravinyltetrameth ylcyclotetrasiloxane) (PV4D4) film using initiated chemical vapor deposition (iCVD), followed by lithiation for 3 days in a 1 M solution of LiClO4 in propylene carbonate (PC) and annealing at 110 °C for 1 hour, results in partial capillarity‐driven collapse of cylinders and the formation of porous CNT “microcupcakes” that offer potential application as electrodes in 3D Li+ batteries. More details can be found in article number https://doi.org/10.1002/admi.201801247 by Srinivasa Kartik Nemani, Hossein Sojoudi, and co‐workers. Courtesy of Hossein Sojoudi, Sanha Kim, and Gareth H. McKinley, Karen K. Gleason, and A. John Hart groups at MIT.

Macrocycles provide intricate shape manifolds that leverage the depth of the modern organic chemistry toolbox. Novel chemistry can be introduced via new bond types and unique torsional angles inaccessible by traditional small molecules and biomolecules. In this work, we investigate the conformational space of a class of biscationic macrocycles in protic and aprotic solvents using a combination of ion-mobility spectrometry mass spectrometry, distance geometry modeling, and quantum mechanical calculations. We identify at least three major conformations of the macrocycles. Two of the conformations are rotational isomers in which the amide (carbonyl amide) N–C bond of the acyl hydrazine can adopt either E- or Z-configuration. The E- and Z-rotational isomers were separately observed in previous X-ray crystallography studies on the same set of macrocycles, but both isomers were never proved to exist for the same molecule. We show that low-dielectric solvents and counterions, such as Cl– or PF6 –, appear to stabilize the Z-conformation. Lastly, desolvation of the macrocycles in the absence of bound counterions yields a gas-phase “flat” Z-conformation. Our results suggest that the macrocycles are flexible and behave much like short polypeptides. The combination of ion-mobility spectrometry mass spectrometry and distance geometry modeling provides a versatile and robust approach to unravel fundamental information on the flexible chemical space of macrocycles.