Passive droplet control is critical for next-generation water harvesting, fluidic logic, and adaptive wetting surfaces. Here, we report a scalable, topography-free slippery liquid-infused porous surface (SLIPS) based on poly[1-phenyl-2-[p-(trimethylsilyl)phenyl]acetylene] (PTMSDPA). By selectively chemically fluorinating specific regions of the porous PTMSDPA film, followed by sequential infusion of two immiscible hydrophobic lubricants into their respective affinity-matched polymer matrices, this approach enables interfacial energy contrasts that direct droplet motion. The heterogeneous oil-infused porous surface (HOIPS) has a unique intrinsic fluorescence enabling real-time, dye-free visualization of infiltrated lubricant domains. Owing to its ultrathin (∼200 nm) and flexible polymer structure, the HOIPS enables controllable droplet motion on flat, flexible, and curved substrates without reliance on surface topography, physical confinement, or asymmetric geometries. Sub-millimeter-scale HOIPS line patterns enable controlled droplet coalescence, shedding diameter, and release timing during condensation, and optimized patterns exhibit up to 2.5× higher water-harvesting performance compared to fluorinated-oil-based SLIPS, providing a material-efficient strategy for liquid-repellent surfaces. Taken together, these results establish PTMSDPA-based HOIPS as a versatile platform for controlled droplet manipulation and condensation management.

This study investigates the thermal degradation mechanism of cyclopentadienyl tris(dimethylamino) zirconium (CpZr(NMe2)3), focusing on changes in its chemical structure and physical properties under elevated temperatures ranging from 100 to 180 degrees C. Thermal degradation begins with the cleavage of the weakest Zr-N bond in the molecule, resulting in the generation of reactive radicals that subsequently recombine to form Zr-C-Zr linkages, which bringing cyclopentadienyl (Cp) ligands into closer proximity, thereby enhancing both intramolecular and intermolecular pi-pi interactions. NMR, XPS, and GC/MS analyses revealed the formation of oligomers, with radical recombination leading to an increase in both the molecular weight and viscosity. The viscosity significantly increased as the purity of CpZr(NMe2)3 decreased, indicating the formation of recombination products with a higher molecular weight. The stability of the Cp ligand plays a key role in facilitating the recombination process. Furthermore, viscosity proved to be a highly sensitive indicator for evaluating the extent of thermal degradation, as it correlates with molecular weight changes and recombination processes. These findings provide valuable insights into the molecular mechanisms of thermal degradation in organometallic compounds, enhancing our understanding of the stability and reactivity of Cp-based precursors.

Pyrolysis of poly(DNap-OH) results in the formation of disordered carbon with high char-yield. The pyrolyzed Poly(DNap-OH) shows enhanced electrochemical performance in SIBs via surface-induced Na + storage, attributed to N- and O-moieties.

This study offers a detailed quantitative evaluation of microscale properties of polymers utilizing the surface and interfacial cutting analysis system (SAICAS) technique. The investigation focuses on the formation of the primary shear zone (PSZ) during cutting, leading to plastic deformation and subsequent chip curling. This research explores various cutting thicknesses, each demonstrating unique chip formation, and applies a lubricant to mitigate friction noise and stabilize chip formation. An in-depth analysis of force geometries is performed to gain insights into chip formation. The shear strength and shear viscosity are calculated using relevant equations, thus enabling the quantitative characterization of the viscoelastic behavior of polymers. Remarkably, the polymers exhibit shear thinning behavior, where their resistance to shear decreases as the shear rate increases. The shear viscosity–shear rate plot follows the Ostwald-de Waele relationship, indicative of plastic flow behavior. The viscoelastic characteristics were validated by comparing the values calculated based on Atkins's theory with the quantified values. Then, the physical meaning of those values were discussed. This study facilitates the direct measurement of mechanical properties in solidified form of the polymer, offering a more precise representation than traditional test piece measurements. In addition, shear viscosity determination of cross-linked materials without pretreatment is achieved, broadening the scope of material analysis through quantitative comparisons.

SiNx thin films have garnered attention as promising barrier films, primarily due to their low impurity diffusion rates, making them suitable for various technological applications. Despite their potential, these films face challenges because they are prone to degradation in hostile environments. This study investigated the oxidation behavior of SiNx thin films, particularly when deposited on two different types of substrates: rigid silicon (Si) and flexible polyethylene terephthalate (PET) films. A thorough microstructural analysis of the SiNx films reveals their detailed morphological and compositional characteristics, enabling a comparison between the SiNx/Si and SiNx/PET films. This study further investigates the impacts of high-temperature and humidity exposure on SiNx thin films, systematically elucidating the degradation behaviors and underlying mechanisms. The structural evolution during SiNx film oxidation is illustrated at the nanoscale, and the factors contributing to the oxidation were analyzed. This study deepens our understanding of the interplay between oxidation processes and the unique environmental conditions of substrates, offering insights into enhancing the stability and reliability of these materials.

A polydiphenylacetylene derivative containing a trimethylsilyl group in one of the two side phenyl rings (PDPA-C1) was examined for use in a film-type solid-state sensor to determine the viscosity of various fluids, such as alcohols, fatty oils, and mineral oils. The fluids readily diffused into the polymer film upon contact and, simultaneously, the fluorescence (FL) emission increased with time to reach a FL enhancing equilibrium. The FL enhancing rate decreased as the viscosity of the fluids increased. The relationship between the time to reach the FL enhancing equilibrium (teq, FL) and the viscosity of each fluid (η) was captured well by a modified Forster–Hoffmann equation, log teq, FL = C + x log η. The slope (x) values indicate the viscosity sensitivities of the PDPA-C1 film for the fluids, which were determined to be 1.02 for alcohols, 4.15 for fatty oils, and 0.63 for mineral oils. This sensing process yielded not only significantly higher viscosity sensitivities but also higher reproducibility than the conventional sensing process based on the measurement of FL intensity. The typical Forster–Hoffmann equation did not capture the relationship between the probe FL intensity and the fluid viscosity well. The unknown viscosities of commercial oils were identified exactly using the modified Forster–Hoffmann equation as a calibration curve.

Conjugated polyelectrolytes (CPEs) are emerging as promising materials in the sensor field because they enable high-sensitivity detection of various substances in aqueous media. However, most CPE-based sensors have serious problems in real-world application because the sensor system is operated only when the CPE is dissolved in aqueous media. Here, the fabrication and performance of a water-swellable (WS) CPE-based sensor driven in the solid state are demonstrated. The WS CPE films are prepared by immersing a water-soluble CPE film in cationic surfactants of different alkyl chain lengths in a chloroform solution. The prepared film exhibits rapid, limited water swellability despite the absence of chemical crosslinking. The water swellability of the film enables the highly sensitive and selective detection of Cu2+ in water. The fluorescence quenching constant and the detection limit of the film are 7.24 × 106 L mol-1 and 4.38 nM (0.278 ppb), respectively. Moreover, the film is reusable via a facile treatment. Furthermore, various fluorescent patterns introduced by different surfactants are successfully fabricated by a simple stamping method. By integrating the patterns, Cu2+ detection in a wide concentration range (nM-mM) can be achieved.

The performance of zirconia nanoparticles (ZrO2 NPs) is critically dependent on their dispersion and stability. Effective control of NP dispersion is crucial for achieving a high refractive index, transparency, and exceptional mechanical properties in organic-inorganic hybrid films that incorporate ZrO2 NPs. In this study, we compared the crystalline properties and stability of ZrO2 NPs synthesized via two distinct methodologies: solvothermal synthesis using a zirconium isopropoxide isopropanol complex (ZII, Zr(OCH(CH3)2)4·(CH3)2CHOH) and sol-gel synthesis using zirconyl chloride octahydrate (ZC, ZrOCl2·8H2O). Both solutions exhibited precipitation, and the particles showed aggregation behavior. Despite being in a suspended state, the particles synthesized using the ZII precursor (T-ZrO2) exhibited hard-sphere behavior, distinct interparticle boundaries, and a tetragonal crystalline phase. However, the particles produced using the ZC precursor (A-ZrO2) were nearly amorphous without well-defined sizes and morphologies. Further, the hydroxyl end groups of both particle types were exchanged using a silane coupling agent (3-(trimethoxysilyl)propyl methacrylate, TMSPM) via hydrolysis and condensation reactions. The presence of the TMSPM groups on the surface of ZrO2 NPs afforded surface-modified TMSPM-T-ZrO2 with enhanced stability and prevented particle aggregation, thus maintaining the dispersion stability for up to one year under ambient conditions. The low surface energy and stabilization of the TMSPM-T-ZrO2 NPs were influenced by the tetragonal crystalline phase, which was conducive to surface modification using a silane coupling agent.

Polyamideimides and polyimides are prepared based on chemical imidization using aromatic diamine, diacid anhydride, and diacid chloride as monomers, with the precursor polyamic acid remaining in part, to produce mechanically unique films through convection drying. The resulting films are colorless and transparent and exhibit unidirectional fracture behavior. These films do not break when bent in the direction of the air contact surface but easily break when bent in the opposite direction. A cross‐sectional electron microscope image of the broken film shows that the film consists of a double layer. After examining both sides of the film through various spectroscopic and gel permeation chromatography analyses, it is found that the residual polyamic acid undergoes both hydrolytic and thermal decomposition, exclusively on the air contact surface. Later, the polymer film is laminated with two sheets of glass through UV curing of commercial acryl resin. Because of the unidirectional fracture characteristics of the film, the laminated glass does not completely break when subjected to bending toward the air contact surface but easily breaks (without fragments) in the opposite direction, indicating its potential application in safety glasses suitable for emergency escapes.

Excellent thermal and mechanical properties of aromatic polyimides (PIs) make them attractive materials in various fields. PIs is performed using polyamic acid (PAA) precursors due to their limited solubility. However, PAAs can be easily depolymerized by moisture and heat, which can degrade the properties of PIs. Therefore, quality control of PAAs is an important task in researches and industrial applications. Here, we propose a simple, rapid, and novel method to observe the depolymerization of PAAs. The method is based on the principle that, as the molecular weight of the polymer decreases, the solution viscosity decreases, and the viscosity of the solution can be easily and rapidly measured using electrochemistry. We accelerated depolymerization by applying heat to a PAA solution and measured the change in viscosity of the solution through cyclic voltammetry. The proposed method, which also makes it possible to determine the dynamic viscosity of a polymer solution, is presented as a model system to observe state changes in various polymers.

The piezochromic fluorescence (FL) of a distyrylpyrazine derivative, 2,3-diisocyano-5,6-distyrylpyrazine (DSP), was investigated in this study. Depending on the recrystallization method, DSP afforded two different crystals with green and orange FL emission. The orange color FL emission crystal (O-form) was easily converted to the green color FL emission one (G-form) by manual grinding. The G-form was also converted to a slightly different orange color FL emission crystal (RO-form) by a weak UV irradiation. When the RO-form was ground again, the G-form was regenerated. The FL colors changed between the G- and RO-forms over several ten times by repeated mechanical grinding and UV irradiation. The FL, UV–visible, 1 H-NMR and XRD results showed that the O (or RO)-to-G transformation induced by mechanical stress results from the change of degree of molecular stacking from dense molecular stacking structure to relatively loose molecular stacking structure, whereas the G-to-RO reconversion by UV irradiation results from return to dense molecular stacking structure again due to lattice movement (lattice slipping) allowed by photocycloaddition in solid-state.

Migration of ions such as sodium from a glass surface to organic materials in contact is critical for the use of glass as a supporting material for film casting. In this study, we report the surface defect formation of annealed poly(pyromellitic dianhydride-co-4,4′-oxydianiline) (PMDA-ODA) film after detaching the film from soda-lime glass via ion migration. The defect was porous and sodium was observed as one of the major impurities in the defect. We propose that the defect forms as a result of the ion migration from glass and thermal decomposition of PMDA-ODA. The ions released from glass at a sufficiently high temperature form hydroxide compounds during the floating of the film on the water and readily attacks the imide ring at the glass-film interface. The ionic bonds are broken by thermal annealing and diffuse throughout the film, finally defects form by both segregation of ions to the film surface and PMDA-ODA decomposition.

The design and preparation of hollow nonspherical microparticles are of great significance for their potential applications, but the development of a facile synthetic method using only one production step remains a great challenge. In the current work, a new template-free method based on dispersion polymerization was successfully developed to produce anisotropic hollow polystyrene (PS) microparticles in a single step. In the synthesis, ammonium persulfate (APS) played a critical role in the formation and growth of highly uniform and stable hollow PS microparticles. By varying the concentration of APS and that of the stabilizer used, polyvinylpyrrolidone, we were able to control the average size of the PS particles and their degree of concavity. Based on our results and observations, a plausible mechanism for formation of these unusually shaped PS microparticles was proposed.

Highly efficient and stable BDT2TR:PNDI-2T organic solar cells are investigated. Although this system shows a PCE of 4.43%, significant enhancements are observed in the thermal stability, high thickness tolerance, and flexibility as compared with the PC71BM-based organic solar cells.

The porous graphene-based materials are regarded as a promising adsorbent for the adsorption of greenhouse gases such as CO2 and SO2 due to their excellent physical and textural properties, but the adsorption capacity needs to be improved by creating multiscale porosity and large surface area. In this study, we present the synthesis of three-dimensional (3D) ultralight, macro-and micro-porous reduced graphene oxide (m(2)-RGO) monoliths through a self-assembly and steam activation process. Along with 3D macrosopic frameworks, the as-obtained adsorbents possess a ultralow density of 10.4 mg/cm(3), a large specific surface area of > 1600 m(2)/g and a ultrahigh porosity of > 98%, which is suitable for high performance adsorbents. As a consequence of multiscale porosity and good textures, the m(2)-RGO adsorbents exhibit much higher capacities of 6.31 mmol/g and 2.97 mmol/g compared to 2.68 mmol/g and 1.36 mmol/g of 3D macro-porous reduced graphene oxide (m-RGO) for the capture of CO2 and SO2 gases. Moreover, the adsorption kinetics of the m(2)-RGO is much faster than that of commercial RGO powder due to the 3D interconnected macroporous pathways. (c) 2016 Elsevier Ltd. All rights reserved.

Conjugated-polymer nanofibers with a thermodynamically stable, coarsened, disordered structure in an amorphous glassy state were fabricated via a freeze-drying method using a poly(diphenylacetylene) derivative. The nanofibers were extremely emissive, with a fluorescence (FL) quantum yield of approximately 0.34, which was much higher than that of both the cast film (0.02) and the solution (0.21). Similarly, the amplitude-weighted average FL lifetime of the nanofibers was 0.74 ns, which was much longer than that of the film (0.29 ns) and the solution (0.57 ns). This unusual and enhanced FL-emission behavior was attributed to the abruptly quenched chain structure that was created by the freeze-drying process. The polymer chains in the nanofibers remained frozen-in and the side phenyl rings were retained in a relaxed state. The metastable chains did not undergo vibrational relaxation and collisional quenching to generate the radiative emission decay effectively.

This paper reports a unique fluorescence (FL) response and diverse applications of conjugated polyelectrolyte (CPE) through nonelectrostatic interaction with appropriate (bio)surfactants in an immiscible two-phase system. A sulfonated microporous conjugated polymer (SMCP) with a conformation-variable intramolecular stacked structure was used as the CPE film. Despite the extremely high hydrophilicity, the SMCP film responded significantly to the hydrophobic circumstances, either physicochemically or electronically, in the presence of water-in-oil (w/o)-type nonionic surfactants with appropriate hydrophile-lipophile balance (HLB) values. The polymer film became fully wet with hydrophobic solvents due to the addition of small amounts of (bio)surfactant to reveal remarkable FL emission enhancement and chromism. Microcontact and inkjet printing using the SMCP film (or SMCP-adsorbed paper) and the surfactant solution as substrate and ink, respectively, provided high-resolution FL images due to the distinctive surfactant-induced FL change (SIFC) characteristic. Moreover, the additional electrostatic interaction of SMCP film with oppositely charged surfactants further enhanced the FL emission. Our findings will help comprehensive understanding of the nonelectrostatic SIFC mechanism of CPEs and development of novel SIFC-active materials.

In this paper, specific molecular design rules are proposed for highly fluorescent, photostable, conjugated polymer dots (CPDs) applicable for the bioimaging of live cells. CPDs are prepared by nanoprecipitation in water using polydiphenylacetylene (PDPA) derivatives and commercial conjugated polymers. Among these, an amorphous, glassy‐state PDPA derivative provides highly porous, coarsened nanoparticles. The nanoparticles are dispersed very well in water, and the polymer chains are either hydrodynamically or thermodynamically stable, with a fully relaxed intramolecular stacked structure. This leads to effective radiative emission decays by restraining collisional quenching and vibrational relaxation to achieve an extremely high fluorescence (FL) quantum efficiency. The FL emission quantum yield is as high as 0.76, which is the highest value among those reported for conventional CPDs. The PDPA‐based CPD has a very low photobleaching quantum yield (∼10 −9 ), because of its relatively high ionization potential. This aqueous colloidal solution is useful for bioimaging plant and mammalian cells. The excellent FL quantum efficiency, photostability, and cellular uptake suggest that the present CPD is a very promising probe for bioimaging, particularly for long‐term imaging and tracking in live cells or experimental animals.

Localized self-assembly of conjugated polyelectrolytes (CPEs) in a film is realized by simply contacting the film to appropriate surfactant solutions. This in situ self-assembly allows simultaneous optical and structural reforming on the selected areas and highly resolved patterning of the CPE film. As a service to our authors and readers, this journal provides supporting information supplied by the authors. Such materials are peer reviewed and may be re-organized for online delivery, but are not copy-edited or typeset. Technical support issues arising from supporting information (other than missing files) should be addressed to the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Highly advanced phase-change hybrids (PCHs), which consist of a phase-change material and conjugated polymer, were developed for new sensor and actuator applications. PCH films with excellent characteristics were obtained simply by depositing various molten paraffin waxes (PWs) in situ onto poly(diphenylacetylene) (PDPA) films with extremely large fractional free volumes. The phase-change enthalpy of the PWs in the hybrid films was quite high and remained constant over prolonged use. The PCH films underwent critical changes in both fluorescence (FL) intensity and color during the phase change of the PWs, which facilitated various sensor applications such as highly reversible writing/erasing, fingerprinting and array-type thermometer usage. In addition, a biaxially oriented polypropylene (BOPP)-supported PCH film exhibited extremely fast and highly reproducible thermomechanical actuation with reversible curling/uncurling during the phase change of the PWs. These findings will be useful for developing novel PCH materials with highly advanced functions and applications.