Crowellhardin9988

Positive charges and hydrophobicity were found to particularly hinder diffusion, and the different results suggested on the whole the presence of NPs-matrix interactions, therefore underlying the importance of the ECM model. The accuracy of the tumor-derived gels used in this study was evidenced by in vivo experiments involving intratumoral injections of NPs on mice, which showed that diffusion patterns in the peripheral tumor tissues were quite similar to the ones obtained within the chosen ECM model.Laser processing is an emerging technique capable of synthesizing metal-silicon composite surfaces for various applications. However, little is known about the chemical composition of these laser-processed surfaces, and the reaction mechanisms leading to their formation are poorly understood. In this work, we report the formation of gold-silicon nanostructured surfaces through reactive laser ablation in liquid. Silicon wafers were immersed in pH-controlled solutions of KAuCl4 and processed with ultrashort laser pulses. Gold deposition on the silicon wafers was found to depend on the pH of the precursor solution neutral solutions (pH ∼6.3) resulted in much higher gold deposition than acidic or basic solutions. Laser processing of silicon wafers in water followed by immersion in the KAuCl4 solution resulted in lower gold deposition. X-ray photoelectron spectroscopy and depth profiling showed the existence of both gold (Au0) and gold-silicide (Au x Si) phases on the surfaces. Under both types of processing conditions, the gold atomic fraction and gold-silicide content increased with depth to at least 150 nm into the surface of the silicon wafer, although significantly more gold and gold-silicide were formed when the silicon was ablated in KAuCl4 solution as compared to immersion in KAuCl4 after ablation in water. Based on these data and existing literature on laser processing of silicon, we propose mechanisms that explain the observed gold penetration depth and its deposition dependence on solution pH. The mechanistic understanding gained in this work may be useful for synthesizing a variety of metal-silicon composite surfaces through laser processing to prepare functional materials such as catalysts and surface-enhanced Raman spectroscopy substrates.Nanopillar structure processing has been performed on condensation surfaces to control wettability and achieve a high heat transfer coefficient via dropwise condensation and jumping droplets. Modified dry etching was performed using gold (Au) nanoparticles generated by annealing Au as a mask. High-aspect-ratio nanopillar processing was also performed to produce uniform pillar surfaces and novel hierarchical pillar surfaces. A uniform nanopillar surface with pillars having diameters of 20-850 nm and a hierarchical pillar surface with thick pillars having diameters ranging from 100 to 860 nm and thin pillars with diameters ranging from 20 to 40 nm were mixed and fabricated. Condensation experiments were performed using the noncoated nanopillar surfaces, and the condensation behaviors on the silicon (Si) surfaces were observed from above using a microscope and from the side using a high-speed camera. On the uniform surface US-3 and the hierarchical surfaces HS-1 and HS-2, droplet jumps were observed frequently in the droplet size range of 20-50 μm. In contrast, as the droplet size increased to 50 μm or more, the number of jumps observed decreased as the droplet size increased. The frequency of droplet jumps on the hierarchical surfaces from the start of condensation to approximately 2 min was higher than that on the uniform surfaces, although the density of droplet formation on the hierarchical surfaces was not relatively large. On the basis of the observation of droplet behavior from the side surface, we identified that the primary jump was due to the coalescence of droplets adhering to the surface and that the subsequent jump was caused by the droplet coalescence when the jump droplets were reattached. The primary jump occurrence rate was high on all pillar surfaces.Because of its widely known antifouling properties, a variety of lithographic approaches has been used to pattern surfaces with poly(ethylene glycol) (PEG) to control surface interactions with biomolecules and cells over micro- and nanolength scales. Often, however, particular applications need additional functions within PEG-patterned surfaces. Monofunctional films can be generated using PEG modified to include a chemically functional group. We show that patterning with focused electron beams, in addition to cross-linking a monofunctional PEG homopolymer thin-film precursor and grafting the resulting patterned microgels to an underlying substrate, induces additional chemical functionality by radiation chemistry along the polymer main chain and that this second functionality can be orthogonal to the initial one. Specifically, we explore the reactivity of biotin-terminated PEG (PEG-B) as a function of electron dose using 2 keV electrons. At low doses (∼4-10 μC/cm2), the patterned PEG-B microgels are reactive with streptavidin (SA). As dose increases, the SA reactivity decays as biotin is damaged by the incident electrons. Independently, amine reactivity appears at higher doses (∼150-500 μC/cm2). At both extremes, the patterned PEG microgels retain their ability to resist fibronectin adsorption. We confirm that the amine reactivity derives from the PEG main chain by demonstrating similar dose response in hydroxy-terminated PEG (PEG-OH), and we attribute this behavior to the formation of ketones, aldehydes, and/or carboxylic acids during and after electron-beam (e-beam) patterning. Based on relative fluorescent intensities, we estimate that the functional contrast between the differentially patterned areas is about a factor of six or more. This approach provides the ability to easily pattern biospecific functionality while preserving the ability to resist nonspecific adsorption at length scales relevant to controlling protein and cell interactions.Aggregation-induced emission (AIE) behavior of water-soluble tetraphenylethene (TPE) derivatives bearing carboxy and sulfo groups was studied at polarized liquid|liquid interfaces. The aggregation behavior of TPE derivatives in solution and at the water|1,2-dichloroethane (DCE) interface was highly dependent on their ionizable functional groups. Spectroelectrochemical analysis elucidated that the TPE derivatives were transferred across the interface accompanied by the adsorption process at the interface. The ion transfer and interfacial AIE features of TPEs responded reversibly to the externally applied potential, indicating no rigid crystalline structure formation in the interfacial region. The red shift measured in intense interfacial emission spectra demonstrated that the carboxylate derivatives formed their J-aggregates specifically at the polarized water|DCE interface, while the aggregation processes with distinguishable emission properties took place in both the interfacial region and organic solution in the sulfonate derivative system. The AIE features were also investigated at a glycerophospholipid-adsorbed interface as a model of the biomembrane surface. The aggregation process of TPE derivatives was significantly modified through the interaction with phospholipid layers which stimulate the interfacial AIE process of tetra-anionic TPEs.Carbonated water droplets can ease the difficulties faced by distilled water droplets mitigating dust particles from hydrophobic surfaces. Rising of CO2 bubbles in carbonated water droplets and their interaction with the flow structure, created by Marangoni and buoyancy possessions, in droplets are investigated. Spreading and infusion (cloaking) of carbonated water on dust surfaces are analyzed, and the rate at which bubbles formed inside the carbonated water droplet, as placed on a dusty hydrophobic surface, is examined. Flow structures formed inside the carbonated water droplet are simulated, and findings are compared to those corresponding to the distilled water droplet. Dust mitigation from the hydrophobic surface toward droplet liquid inside is evaluated using the high-speed recording system, and the results are compared with those of predictions. It is found that carbonated water spreads and infuses onto dust particles at a higher rate than that at which distilled water does. The rising bubble generates wake-like flow in the fluid while modifying the flow structure inside the droplet; hence, the number of circulating structures increases from two to four in droplet fluid. click here The dust particles picked up by flow currents are redistributed over the entire carbonated water droplet, while mitigated dust particles remain in the lower region of the distilled water droplet. Bubbles formed inside the carbonated water droplet improve dust lifting and rate of dust mitigation from the surface.Droplet impact on arbitrary inclined surfaces is of great interest for applications such as antifreezing, self-cleaning, and anti-infection. Research has been focused on texturing the surfaces to alter the contact time and rebouncing angle upon droplet impact. In this paper, using propagating surface acoustic waves (SAWs) along the inclined surfaces, we present a novel technique to modify and control key droplet impact parameters, such as impact regime, contact time, and rebouncing direction. A high-fidelity finite volume method was developed to explore the mechanisms of droplet impact on the inclined surfaces assisted by SAWs. Numerical results revealed that applying SAWs modifies the energy budget inside the liquid medium, leading to different impact behaviors. We then systematically investigated the effects of inclination angle, droplet impact velocity, SAW propagation direction, and applied SAW power on the impact dynamics and showed that by using SAWs, droplet impact on the nontextured hydrophobic and inclined surface is effectively changed from deposition to complete rebound. Moreover, the maximum contact time reduction up to ∼50% can be achieved, along with an alteration of droplet spreading and movement along the inclined surfaces. Finally, we showed that the rebouncing angle along the inclined surface could be adjusted within a wide range.Zwitterionic molecules are known to resist nonspecific protein adsorption and have been proposed as an alternative to the widely used polyethylene glycol. Recently, zwitterionic-like nanoparticles were created from the coimmobilization of positive and negative ligands, resulting in surfaces that also prevent protein corona formation while keeping available sites for bioconjugation. However, it is unclear if they are able to keep their original properties when immersed in biological environments while retaining a toxicity-free profile, indispensable features before considering these structures for clinics. Herein, we obtained optimized zwitterionic-like silica nanoparticles from the functionalization with varying ratios of THPMP and DETAPTMS organosilanes and investigated their behavior in realistic biological milieu. The generated zwitterionic-like particle was able to resist single-protein adsorption, while the interaction with a myriad of serum proteins led to significant loss of colloidal stability. Moreover, the zwitterionic particles presented poor hemocompatibility, causing considerable disruption of red blood cells.