In cancer therapy, drug delivery is a complex process that aims to transit the cargo to the destination with as little damage to the normal tissue as possible. In the last decade, tremendous ...development and research on nanomedicine have been exploring an ideal system with efficient drug transportation and release property. For this end, series of barriers need to be circumvented by nanomedicine, including systemic barriers, such as biosurface adsorption, phagocytic clearance, bloodstream washing, interstitial pressure, degradation, as well as intracellular barriers, such as cell membrane reorganization and internalization, endo/lysosomal escape, cytosolic or subcellular localization. Rather than being random, these barriers follow a specific spatialatemporal sequence. Therefore, the nanocarriers have to be endowed with characteristics that are adaptive to particular biological milieu on systemic and intracellular levels. To this end, we reviewed the correlations between the spatialatemporal sequences of drug delivery and nanocarrier characteristics in cancer therapy, as well as strategies to achieve efficient drug delivery upon both systemic and intracellular levels.
•Realistic kerogen models are generated to quantify the adsorption isotherms.•Effect mechanisms of maturity and moisture on gases adsorption are elaborated.•Adsorption capacity is proportional to ...effective pore volumes of kerogen models.•Moisture effect decreases with increasing maturity at high moisture contents.•Isosteric heat of CO2 adsorption is relevant to sulfur and oxygen atoms content.
The adsorption behaviors of methane (CH4), carbon dioxide (CO2) and their mixtures are vital to understand the process of CO2 sequestration and shale gas exploitation. In this work, four realistic kerogen models with different maturities (immature (IIA), beginning of oil window (IIB), middle of oil window (IIC), postmature (IID)) were built by the molecular dynamics (MD) method. The adsorption characteristics of CH4, CO2 and their mixtures on these kerogen models with various moisture contents (0, 0.7, 1.4, 2.1, 2.8wt%) were investigated by the grand canonical Monte Carlo (GCMC) simulations. The influences of kerogen maturity and moisture content on the adsorption capacity, isosteric heat of adsorption and adsorption selectivity of gas molecules were discussed. Simulation results show that the maximum adsorption capacity of gas molecules increases with increasing kerogen maturity, but decreases with increasing moisture content, and the reduction decreases as the maturity increases at high moisture contents. The average isosteric heat of CO2 adsorption is relevant to the sulfur/oxygen content of kerogen models. The pre-adsorbed water (H2O) has a small effect on the gas isosteric adsorption heat when located in the middle of pores, but can reduce the CO2 isosteric adsorption heat by occupying the hydrophilic groups. Moreover, H2O molecules are observed to migrate and aggregate into growing clusters at higher moisture contents for kerogen IIC and IID models, increasing the gas isosteric adsorption heat. The CO2/CH4 adsorption selectivity gradually decreases to the equilibrium value with the rise of bulk pressure. Also, the selectivity decreases with increasing CO2 mole fraction for lower mature kerogen models (IIA and IIB), but increases with the CO2 mole fraction at low pressure for kerogen models of higher maturity (IIC and IID). Meanwhile, the selectivity increases for IIA, IIC and IID models, while decreases for IIB model as the moisture content increases. This study gains deep insights into the effect of kerogen maturity and moisture content on the interaction between CH4/CO2 and kerogen at microscopic scale.
Protein adsorption at solid surfaces plays a key role in many natural processes and has therefore promoted a widespread interest in many research areas. Despite considerable progress in this field ...there are still widely differing and even contradictive opinions on how to explain the frequently observed phenomena such as structural rearrangements, cooperative adsorption, overshooting adsorption kinetics, or protein aggregation. In this review recent achievements and new perspectives on protein adsorption processes are comprehensively discussed. The main focus is put on commonly postulated mechanistic aspects and their translation into mathematical concepts and model descriptions. Relevant experimental and computational strategies to practically approach the field of protein adsorption mechanisms and their impact on current successes are outlined.
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► We discuss the latest findings on mechanistic details of protein adsorption. ► Important effects: cooperative adsorption, overshootings, relaxation, and aggregation. ► Experimental, mathematical, and computational concepts are reviewed.
The objectives of this study were, firstly, to adsorb biopolymer complexes to an emulsion interface through electrostatic interactions and, secondly, to test the stability of the emulsions covered ...with biopolymer complexes. Whey protein isolate (WPI)aapple pectin complexes made by thermal treatment (85 degree C, 20 min) were successfully adsorbed to the interface of an oil-in-water emulsion stabilized with whey proteins. The stability of the emulsion covered with the WPI-pectin complexes was tested by measuring salt (0a500 mM NaCl), heat (40a90 degree C, 30 min) and freeze-thaw (a20 degree C, 22 h) stability at pH 3.5a4.5. The results revealed that the adsorption of WPI-pectin complexes to the emulsion interface led to the formation of stable emulsions. The most remarkable result was at pH 4.5, where the base emulsion (without biopolymer complexes) was aggregated, but became stable after the deposition of the WPI-pectin complexes. Emulsions covered with WPI-pectin complexes were stable to salt additions up to 200 mM, but aggregated at the 500 mM level of NaCl. They were also resistant to heat treatments, and no aggregation was observed. However, the adsorption of WPI-pectin complexes to the emulsions did not improve the freeze-thaw stability, on the contrary, they showed major aggregation. These results demonstrated that biopolymer complexes can be used to assemble hierarchial emulsion structures and, improve the emulsion stability to environmental stresses.
Composite particles with varying morphologies composed of gold nanoparticles (Au NPs) and polymers were fabricated based on a combination of electrostatic interactions between the polymer particles ...and Au NPs and diffusion processes. The positively charged polymer particles were prepared from amino-terminated polystyrene (PS-NH sub(2)) and amino-terminated 1,2-polybutadiene (PB-NH sub(2)). Adsorption of citrate-stabilized Au NPs resulted in three different distribution states of Au NPs in the polymer particles, depending on the glass transition temperature (T sub(g)) and molecular weight of the polymer. The adsorption of Au NPs onto PS-NH sub(2) particles produced raspberry-like composite particle morphologies, while the NPs instead diffused into the PB-NH sub(2) particles, since the T sub(g) of PB-NH sub(2) is below room temperature. The diffusion of Au NPs could be controlled by varying the molecular weight of the PB-NH sub(2) and the diameter of the NPs, and both core-shell and amorphous distributions were successfully achieved.
A molten salt electrochemical system comprising a eutectic mixture of Li-Na-K carbonates, a Ni cathode, and a SnO sub(2) inert anode is proposed for the capture and electrochemical conversion of CO ...sub(2.) It is demonstrated that CO sub(2) can be effectively captured by molten carbonates, and subsequently electrochemically split into amorphous carbon on the cathode, and oxygen gas at the anode. The carbon materials generated at the cathode exhibit high BET surface areas of more than 400 m super(2) g super(-1) and as such, represent value-added products for a variety of applications such as energy storage and pollutant adsorption. In the carbonate eutectic (500 degree C), the presence of Li sub(2)CO sub(3) is shown to be required for the deposition of carbon from the melt, wherein O super(2-) or Li sub(2)O serves as the intermediate for CO sub(2) capture and electrochemical conversion. SnO sub(2) proved to be an effective anode for the electrochemical evolution of oxygen. Electrochemical reactions were found to proceed at relatively high current efficiencies, even though the current densities exceed 50 mA cm super(-2). The intrinsic nature of alkaline oxides for CO sub(2) capture, the conversion of CO sub(2) to value-added products, and the ability to drive the process with renewable energy sources such as solar power, enables the technology to be engineered for high flux capture and utilization of CO sub(2).
The electrosynthesis from 5‐hydroxymethylfurfural (HMF) is considered a green strategy to achieve biomass‐derived high‐value chemicals. As the molecular structure of HMF is relatively complicated, ...understanding the HMF adsorption/catalysis behavior on electrocatalysts is vital for biomass‐based electrosynthesis. The electrocatalysis behavior can be modulated by tuning the adsorption energy of the reactive molecules. In this work, the HMF adsorption behavior on spinel oxide, Co3O4 is discovered. Correspondingly, the adsorption energy of HMF on Co3O4 is successfully tuned by decorating with single‐atom Ir. It is observed that compared with bare Co3O4, single‐atom‐Ir‐loaded Co3O4 (Ir‐Co3O4) can enhance adsorption with the CC groups of HMF. The synergetic adsorption can enhance the overall conversion of HMF on electrocatalysts. With the modulated HMF adsorption, the as‐designed Ir‐Co3O4 exhibits a record performance (with an onset potential of 1.15 VRHE) for the electrosynthesis from HMF.
Single atoms of Ir are anchored on Co3O4 for efficient electro‐oxidation of 5‐hydroxymethylfurfural (HMF). It is found that an isolated Ir atom can optimize the adsorption configuration of HMF molecules on catalysts and accelerate HMF oxidation.
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Adsorptions are commonly of monolayer coverage of adsorbate molecules on adsorbent sites, in particular for chemisorptions, where Langmuir adsorption isotherm equation and kinetics ...are adequate. The Langmuir adsorption is termed ideal adsorption as the surface active centers are uniformly distributed, the molecules are of point-sizes and the interactions between adsorbate molecules and the adsorbent are uniform. However, there are more cases where Langmuir adsorption isotherm and/or kinetics are inadequate in describing the adsorption behavior. Apparent multilayer adsorption has been shown to be descriptive of both physisorptions and chemisorptions as a means of idealization to nonideal adsorptions. The deviation of adsorption isotherm and/or kinetics from (ideal) Langmuir adsorption is due to cooperative adsorption, or interactions between adsorbates or between adsorbate and adsorbent caused deviation from “uniform” interactions. The multi-layer or apparent multilayer behavior of adsorption is an excellent model to describe cooperative adsorption. Adsorption kinetics and isotherms have been derived for adsorptions without differentiating the different types of adsorptions. The simplistic approach can explain majority of the adsorption isotherms and kinetic behaviors.
•H2 is the Promising Environment Friendly Fuel for Future Use.•Coal is the Cheapest H2 Storage with Largest Capacity.•Sub-bituminous Coal was Successfully Modified with CaO- Nanofluid.•H2 Adsorption ...Hugely Increased in Sub-bituminous-2.•High Selectivity of CO2/H2 was Demonstrated in Sub-bituminous-3.
Hydrogen is a clean energy source which can replace fossil fuels in a hydrogen economy, thereby drastically mitigating climate change. However, hydrogen storage – due to the high volatility of hydrogen – and H2-CO2 separation (a key requirement in the industrial hydrogen production) are currently the main obstacles in implementing such a hydrogen economy.
We thus developed an advanced material which is highly efficient in terms of H2 storage, but also H2 separation fom CO2 streams. We thus modified sub-bituminous coal by incorporating different concentrations of nano-sized CaO nanofluid into the coal. The raw and modified coals (sub-bituminous-1, sub-bituminous-2 and sub-bituminous-3) were characterized and tested for their hydrogen storage capacity and H2-CO2 separation efficiency.
Indeed, sub-bituminous-2 reached a very high H2 adsorption capacity (up to 0.866 mol.kg−1) and clearly can therefore store large quantities of H2. In addition, sub-bituminous-3 demonstrated excellent H2-CO2 separation efficiency (CO2-H2 adsorption selectivities of up to 4.1 were measured). This work therefore illustrates new highly cost-effective and technically efficient materials for H2 storage and H2 production, thus aiding in the industrial-scale implementation of a hydrogen economy.
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