AMPHIPHILIC ASSEMBLIES WITH RESPONSIVE CHARACTERISTICS AT SURFACES AND INTERFACES

Amphiphilic self-assembly has gained a lot of interest in both academic and industrial fields. Amphiphiles have a unique ability to self-assemble in water, providing a range of nanosized materials of various morphologies. Many efforts have been dedicated to developing responsive amphiphilic assemblies by introducing responsive characteristics into the amphiphile building blocks. Responsive assemblies have been utilized in many promising applications such as targeted drug delivery systems, smart sensors, and electronic devices. Here, we reported four different types of responsive assemblies created via the incorporation of different responsive groups either at the material’s surface or interface. To achieve the responsive characteristics at the surface of the assemblies, we designed an amphiphilic homopolymer capable of self-assembly in water to form micelle-like aggregates. The polymer was designed in such a way that the amine functional groups are presented at the surface for further surface modifications. Organic semiconductor molecules were functionalized onto the spherical polymeric micelle-like assemblies and their response in charge transport was analyzed. We utilized the simple spherical micelle-like assemblies as a scaffold to provide isotropic structure in organic semiconductors. Three key findings in this work include 1) the spherical structure to provide isotropic charge transport, 2) the maintenance of charge transport, and 3) the improvement in thermal stability. Furthermore, fluorescent molecules were also functionalized to the spherical micelle to yield fluorescent particles that demonstrated fluorescent enhancement compared to their small molecules counterpart. The mechanism of the emission enrichment was deeply investigated and discussed in the later work. The responsive characteristics at interfaces of amphiphiles were also included in this dissertation. Alternatively to micelle-like assemblies, responsive vesicles were prepared from amphiphilic polymers with three components including hydrophilic, hydrophobic and pH-responsive segments. The positions of the pH-responsive units were optimized to achieve the ability of controlled release. Positions of the responsive groups were varied in the hydrophilic and hydrophobic interface and the effect of the position was examined through kinetic studies of molecular guest release and morphology transitions. Last but not least, the responsive oligomeric amphiphiles were designed to assemble at liquid crystal and water interfaces. Using responsive amphiphiles at such an interface allows the potential to greatly amplify a nanoscopic change into a macroscopic one due to the amphiphile’s response to an applied stimulus. We aimed to develop such a responsive system demonstrating liquid crystal reorganization due to a nanoscopic change of the triggerable amphiphiles interfacial orientation. Our system demonstrates macroscopic changes in liquid crystal optical properties which could contribute to the development of highly sensitive analysis tools

BODIPY dyads and triads: synthesis, optical, electrochemical and transistor properties

A series of D–A dyads and D–A–D triads molecular systems based on triphenylamine and 9-ethyl-carbarzole as donor (D) and BODIPY as acceptor (A) has been designed and synthesized. The optoelectronic properties including optical, electrochemical, and charge carrier mobility of these molecules have been investigated. We found that the D–A–D triads exhibited broader absorption, raising the HOMO energy levels and increase hole carrier mobilities. Analysis surface morphology revealed that BODIPY containing carbazole demonstrated smooth film and no macro phase aggregation was observed upon thermal annealing

Emulsion Technology in Nuclear Medicine: Targeted Radionuclide Therapies, Radiosensitizers, and Imaging Agents

Thunnalin Winuprasith,1 Pankaj Koirala,1 David J McClements,2 Piyachai Khomein3 1Institute of Nutrition, Mahidol University, Nakhon Pathom, 73170, Thailand; 2Department of Food Science, University of Massachusetts Amherst, Amherst, MA, 01003, USA; 3Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Chulalongkorn University, Bangkok, 10330, ThailandCorrespondence: Piyachai Khomein, Division of Nuclear Medicine, Department of Radiology, Faculty of Medicine, Chulalongkorn University, 1873 Rama 4 Road, Pathumwan, Bangkok, 10330, Thailand, Email [email protected]: Radiopharmaceuticals serve as a major part of nuclear medicine contributing to both diagnosis and treatment of several diseases, especially cancers. Currently, most radiopharmaceuticals are based on small molecules with targeting ability. However, some concerns over their stability or non-specific interactions leading to off-target localization are among the major challenges that need to be overcome. Emulsion technology has great potential for the fabrication of carrier systems for radiopharmaceuticals. It can be used to create particles with different compositions, structures, sizes, and surface characteristics from a wide range of generally recognized as safe (GRAS) materials, which allows their functionality to be tuned for specific applications. In particular, it is possible to carry out surface modifications to introduce targeting and stealth properties, as well as to control the particle dimensions to manipulate diffusion and penetration properties. Moreover, emulsion preparation methods are usually simple, economic, robust, and scalable, which makes them suitable for medical applications. In this review, we highlight the potential of emulsion technology in nuclear medicine for developing targeted radionuclide therapies, for use as radiosensitizers, and for application in radiotracer delivery in gamma imaging techniques.Graphical Abstract: Keywords: emulsions, nanoemulsions, nanoparticles, radiosensitizers, radiopharmaceutical

MOESM1 of BODIPY dyads and triads: synthesis, optical, electrochemical and transistor properties

Additional file 1. NMR spectroscopic data, FET and AFM measurements of BODIPY dyads and triads

Large-Molecule Decomposition Products of Electrolytes and Additives Revealed by On-Electrode Chromatography and MALDI

The decomposition of electrolyte and additive molecules has a critical impact on battery performance. In this work, large-molecule decomposition products in solid-electrolyte interphase (SEI) are identified with clear structure assignment by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The MALDI analysis is facilitated by on-electrode chromatography that serves to fractionate different molecular species on the electrode surfaces prior to MS measurements. These methods exemplify a practical and readily adoptable strategy to characterize the organic elements in SEIs

Large-Molecule Decomposition Products of Electrolytes and Additives Revealed by On-Electrode Chromatography and MALDI

The decomposition of electrolyte and additive molecules has a critical impact on battery performance. In this work, large-molecule decomposition products in solid-electrolyte interphase (SEI) are identified with clear structure assignment by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS). The MALDI analysis is facilitated by on-electrode chromatography that serves to fractionate different molecular species on the electrode surfaces prior to MS measurements. These methods exemplify a practical and readily adoptable strategy to characterize the organic elements in SEIs

Random copolymer of poly(polyethylene glycol methyl ether)methacrylate as tunable transition temperature solid-solid phase change material for thermal energy storage

Polymer based phase change materials (PCM) for thermal energy storage (TES) applications have gained some attention recently due to their high stability and potential solid to solid phase transition. Here, we are the first to utilize a simple copolymerization strategy for static tunability transition temperature (Tt) of polymeric PCM. The copolymerization between short and long side chain polyethylene glycol based methacrylate polymers was designed to tune Tt with minimum impact on their energy density. Polarized optical microscope and x-ray techniques were also used to understand the relationship between crystal structure and Tt of different copolymer composition which was discussed in the context. The solid to solid transition polymeric PCM were successfully developed with tunable Tt ranged from 18 °C to 35 °C which is suitable toward building envelop applications

Dynamic tunability of phase-change material transition temperatures using ions for thermal energy storage

Thermal energy storage (TES) based on phase-change materials (PCMs) has many current and potential applications, such as climate control in buildings, thermal management for batteries and electronics, thermal textiles, and transportation of pharmaceuticals. Despite its promise, the adoption of TES has been limited, in part due to limited tunability of the transition temperature, which hinders TES performance for varying use temperatures. Transition temperature tuning of a material using an external stimulus, such as pressure or an electric field, typically requires very large stimuli. To circumvent this problem, here, we report on the dynamic transition temperature tunability of a PCM using ions. We achieve a transition temperature tunability up to 6°C in polyethylene glycol (PEG) by using the salt lithium oxalatodifluoroborate at a low voltage of 2.5 V, which may enable simpler and safer devices/system designs. We also explain the thermal properties of the salt/PCM solution using the Flory-Huggins theory