This paper describes the fabrication of polyelectrolyte microspheres using porous manganese carbonate as a sacrificial template for entrapped photosensitizer (PS) drugs for photodynamic therapy application. These particles were used as templates for polyelectrolyte layer-by-layer assembly (Lbl) of two oppositely charged polyelectrolytes: poly(styrene sulfonate) and poly(allylamine hydrochloride). When the polyelectrolyte multilayer shell was built around the MnCO3 core by the Lbl protocol and the core was extracted with acid solution and EDTA, the resultant assembly consisted of hollow polyelectrolyte spheres. Chloroaluminum phthalocyanine was chosen as the model drug to load into the hollow spheres. All the spectroscopic results presented showed excellent photophysical parameters of the studied drug. The fabrication of polyelectrolyte hollow spheres can be used as an optimal medium for a variety of bioactive materials, which can also be encapsulated by the proposed method.

Refinement and homogenization of primary Si particles in hypereutectic Al–Si alloys is an effective route to enhance the tensile strength and wear resistance and satisfy the industrial requirements for a wide range of applications. Herein, two kinds of semisolid hypereutectic Al–Si alloys are synthesized by using a rotating-rod-induced nucleation technology. The influence of different cooling conditions and shear rates on the apparent viscosity of molten melt of slurry are examined by self-made high-precision and high-temperature apparent viscosity test equipment. The correlation between the shear rate and the uniformity of hard phases has been investigated from the obtained results, fitting curves, and optical microscope. With the increase in the shear rate, the particles tend to become rounder and the apparent viscosity becomes lower. The enhanced shape factor resulted in more rounded grains, which further reduced the apparent viscosity. During the same cooling time, the higher cooling rate resulted in higher solid fraction, generating higher apparent viscosity. The present study provides unique insight into the filling behavior of semisolid hypereutectic Al–Si alloys and serves as a baseline for future work.

Uniform distribution of diamond grains is difficult to achieve using traditional fabrication of the micro grinding wheel. The design and performance of novel resinous diamond composites (RDCs) fabricated by hot pressing molding were studied to fabricate micro resinous diamond grinding wheels. The physical and mechanical properties of RDCs were analyzed by constructing and simulating five kinds of RDCs, including acrylonitrile butadiene styrene (ABS)/polyvinyl chloride (PVC)/dioctyl phthalate (DOP)/diamond materials with different mass ratios. Diamond grains presented good compatibility with the ABS–PVC–DOP copolymer, which resulted in improved mechanical properties of RDCs. RDC1–RDC5 samples were fabricated, and their hardness, surface roughness, and infrared spectra were analyzed. The optimal mass ratio of ABS/PVC/diamond/DOP for fabricating RDCs was 62.5/18.6/10.6/8.3. The results provide guidance in fabricating novel materials for resinous diamond grinding wheels with desirable performances for precision and ultraprecision machining.

Bimetallic nanoparticles (NPs) have attracted a great deal of attention due to the synergistic interaction between metal components. In this work, the thermal process in which the reducing agent is not expensive or hazardous as those in traditional methods was employed to prepare alloy Ag–Cu NPs. The molar ratio between Ag and Cu was varied from 1:9 to 9:1. Nearly monodisperse NPs with alloy structure were characterized by X-ray diffraction and high-resolution transmission electron microscopy with energy dispersive spectroscopy In comparison with monometallic Ag and Cu NPs, the alloyed Ag–Cu NPs showed better monodispersity, especially when the ratio between Ag and Cu was 1:1. Moreover, the alloyed Ag–Cu NPs exhibited enhanced resistance to electromigration and oxidation, the respective problem of pure Ag and Cu. The alloyed Ag–Cu NPs also exhibited improved properties than a mixture of Ag–Cu NPs. This study should serve as the foundation for exploring high performance alloyed bimetallic NPs.

In this report, bulk graphene–reinforced titanium (Ti–Gr) nanocomposite with millimeter thickness was fabricated by selective laser melting process. Demonstrated by the characterizations of scanning electron microscopy, energy dispersive spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectra, graphene nanoplatelets were successfully embedded into the titanium matrix with a uniform dispersion due to a fast heating–cooling process. High-resolution transmission electron microscopy was used to investigate the interface between titanium and graphene, where a certain amount of carbide was formed attribute to the chemical reaction between them during multilayer laser melting. A high density of dislocations was observed surrounding the graphene nanoplatelets in titanium matrix. The strength and elastic modulus of the nanocomposites were significantly improved, which has been demonstrated by nano-indentation tests. The hardness of the bulk Ti–Gr nanocomposites was approximately 1.27 times higher than pristine Ti counterpart. The strengthening mechanisms were discussed in detail.

The effect of polypropylene (PP) molecular weight on the properties of styrene-butadiene-styrene block copolymer (SBS)/PP blends was studied. All SBS/PP blends (50/50 and 90/10) exhibited a sandwich structure where the co-continuous SBS/PP layer was between the top and bottom PP layers. Solvent extraction tests suggested that the continuous phase structure of PP was independent of the blending ratio and PP molecular weight, while the SBS phase changed from a dispersed phase to a continuous phase as the SBS content increased. The decrease in PP molecular weight decreased the PP layer thickness but increased the phase domain size of SBS in SBS/PP(50/50) blends. As a result, less noticeable “stress-hardening” phenomenon was observed. The mechanism for the structural change was attributed to the different melt viscosities of each component. The crystallinity of the blends did not change with the variable PP molecular weight but decreased with the increasing SBS content.

A new deep level transient spectroscopy (DLTS) technique is described, called half-width at variable intensity analysis. This method utilizes the width and normalized intensity of a DLTS signal to determine the activation energy and capture cross section of the trap that generated the signal via a variable, kO. This constant relates the carrier emission rates giving rise to the differential capacitance signal associated with a given trap at two different temperatures: the temperature at which the maximum differential capacitance is detected, and an arbitrary temperature at which some nonzero differential capacitance signal is detected. The extracted activation energy of the detected trap center is used along with the position of the peak maximum to extract the capture cross section of the trap center.

Amorphous/crystalline (A/C) nanolayers provide an effective model system to study the mechanical behavior and size effects of metallic glasses and crystalline metals in confined geometries. In this work, we experimentally investigated the structure–property relationship in A/C nanolayers containing HCP crystalline layers. CuTi/Ti and CuZr/Zr nanolayers were prepared by magnetron sputtering with layer thicknesses in the range 10–100 nm. The hardness values of the CuTi/Ti and CuZr/Zr nanolayers were close to those of the monolithic CuTi and CuZr, respectively. The hardness remained virtually the same for different layer thicknesses as opposed to CuTi/Cu amorphous/FCC crystalline nanolayers, which exhibit increasing strength with decreasing layer thickness. Confined layer slip model predicts that the effective flow stress of HCP crystalline layers is higher than that of the amorphous layers. As a result, the strength and size effects are governed by the mechanical behavior of the softer amorphous layer.

A bimetallic metal–organic frameworks (MOFs)-templated strategy was developed to fabricate mesoporous CdxZn1−xS polyhedrons with improved photocatalytic hydrogen evolution activity, and the formation mechanism of these mesoporous polyhedrons was discussed in detail. Incorporating Cd atoms, the Brunauer–Emmett–Teller surface areas of mesoporous CdxZn1−xS polyhedrons were significantly increased (271 m2/g), providing more exposed active sites compared with ZnS. In addition, suitable conduction band potential (< −0.55 eV) of the mesoporous CdxZn1−xS polyhedrons was also beneficial for the photocatalysis. Impressively, by the co-effects of mesoporous structure and modified conduction band, the mesoporous CdxZn1−xS polyhedrons exhibited better photocatalytic activity for hydrogen evolution than most reported photocatalysts without noble metals. The maximum hydrogen evolution rate of the CSZ3 reached 4.10 mmol/(h g) under visible-light irradiation and without any cocatalyst condition. This facile strategy for the construction of mesoporous CdxZn1−xS polyhedrons provided a deep insight to fabricate other metal sulfides for a variety of photochemical applications.

Conventional methods for determination of trace drug residues are either time consuming or labor intensive or require large specialized instruments, which hamper their practical applications in field analysis. Here, we present a rapid and quantitative surface-enhanced Raman scattering (SERS) detection method coupled with a portable Raman spectrometer for determination of trace drug residues on fish surface. Graphene oxide (GO) decorated popcorn-like Ag nanoparticles (NPs) on Cu plate (GO/AgNPs/Cu) were fabricated by a facile approach and directly employed as a robust SERS detection substrate. For practical SERS detections, trace-level residues of crystal violet (10−8 M, 4.1 ng/g) and malachite green (10−8 M, 3.6 ng/g) could be readily detected by simply swabbing the contaminated fish scale surface with the SERS substrate. Importantly, SERS detection was quantitatively realized in the broad linear concentrations. Compared with lab-based Raman spectrometer with large footprints, our method has potential applications in practical rapid, accurate, and on-site SERS determination.

The recent observation of spectacular photocatalytic activity enhancements generated tremendous interest in the synthesis, properties, and potential applications of black titania. Most black titania are core–shell structures consisting of a perfect crystalline core surrounded by a defective surface shell. Because the properties are attributed to the defective shell, it is particularly important, but very challenging, to obtain atomic structure information of the core, the shell, and the core–shell relationship on a single particle level. While the role of various synthesis approaches for producing black titania with different properties has been extensively reviewed, this review focuses on understanding the structure–functionality relationship in black titania on a single particle level. We start by introducing the crystal and electronic band structure of different TiO2 phases, followed by the discussion of particle size effects, the origin of lattice distortions, and phase control by synthesis, and concluding with the discussion of crystalline order formation and evolution creating the defective shell.

The current paper focuses on the issue associated with the biological response of medical grade cobalt chromium (Co–Cr) alloy treated with electrical discharge at different spark energy levels by a varying current, pulse on-time, and pause (off) time. Three types of electrodes, namely, graphite (C), tungsten (W), and copper tungsten (Cu–W) were utilized for treating Co–Cr substrates in two different dielectric media such as mineral oil and deionized water. Electrochemical potentiodynamic tests were performed to investigate the corrosion resistance of untreated and treated surfaces. Furthermore, in vitro hemocompatibility tests were executed on the superior corrosion resistance samples for scrutinizing the red blood cell lysis (human blood response). The study revealed a significant improvement in the corrosion resistivity (<80%) and biological response for the surface treated with W–Cu electrode at low pulse pause duration. X-ray diffraction verified the formation of oxides and phosphides on the treated surface that promotes the biocompatibility.

Three-dimensional (3D) biomimetic scaffolds are critical for tissue engineering to support stem cell culture and organoid formation. Embryonic stem (ES) cells hold promising potential for tissue regeneration and ES cell-derived specific lineages are expected to be strongly influenced by the size of embryoid bodies (EBs). However, the fundamental knowledge needed to achieve the goal of highly reproducible, efficient, and scalable differentiation of how EB size affects differentiation is missing. Here, we used 3D biomimetic scaffolds with highly uniform porous structure to regulate size of EBs and differentiated them toward hepatic fate. The results showed EBs formed within the scaffolds were precisely controlled by pore sizes of the scaffolds. We found that EBs equals to or larger than 180 ± 27 µm maintained the ability to differentiate to hepatic lineage. The 3D biomimetic scaffold provides the effective tools toward accurate regulation of EB sizes for tissue engineering.

Highly radioactive waste is incorporated into a glass matrix to convert it into a safe, passive form suitable for long-term storage and disposal. It is currently known that alpha decay can generate gaseous species, which can nucleate into bubbles, either through the production of helium or from ballistic collisions with the glass network that liberate oxygen. An effective method to probe this phenomenon utilizes ion beams to either directly implant helium or investigate the damage due to ballistic collisions. This paper provides an overview of the methodology, summarizes the results of current studies, and draws comparisons between them. We find that the irradiation scheme as well as the temperature and composition of the glass are important in determining whether bubble formation will occur. We also explore how analytical techniques can promote bubble formation and suggest avenues for further work.

In this work, carbon nanotubes (CNTs)-templated binuclear metallophthalocyanines (MTAPcCF3)2C (M = Mn, Fe, Co, Ni, Cu, Zn) assemblies (MTAPcCF3)2C–COOH–CNTs are designed and obtained. Whereafter, the structure and morphology of target products are analyzed by many means such as infrared, X-ray diffraction, X-ray photoelectron spectroscopy, and scanning electron microscopy. The electrocatalytic performances of lithium-thionyl chloride battery catalyzed by (MTAPcCF3)2C–COOH–CNTs were carried out. The result shows that all catalysts can improve the battery performance including the discharge time and the initial voltage. The catalytic performance of (MTAPcCF3)2C–COOH–CNTs is ordered following the central metal: Mn > Fe > Ni > Co > Cu > Zn. The cell capacity catalyzed by optimal catalyst (MnTAPcCF3)2C–COOH–CNTs can expand to 28.08 mAˑh, with increase by 142.07%, and the (MnTAPcCF3)2C–COOH–CNTs can extend the discharge time to 551.6 s. Besides, the reaction mechanism is presented on the basis of cyclic voltammetry measurements.

Utilizing the experimental and modeling approaches, the Gamma radiation effects on stress responses of the silicon rubber foam under quasistatic compression are investigated. In the experimental work, the samples of the silicon rubber and the silicon rubber foams are quasistatically compressed before and after the Gamma radiation (a dose of 500 kGy and a dose rate of 100 Gy/min). The data reveal that the Gamma radiation obviously increases the material hardness, e.g., the compressive stresses of the silicon rubber and the silicon rubber foams both increase over 5 times as the strain is 20%. In the simulation work, a multiscale method combined with finite element method is developed to numerically predict the compressive stress of the silicon rubber foams. The microscale models are first constructed based on the real microstructures of the silicon rubber foams. The compressive stress and strain relation before and after the Gamma radiation is then simulated and obtained utilizing the phenomenological constitutive models based on the testing data of the silicon rubber. The simulation reveals that the Gamma radiation strongly affects the compressive response of the microscale models. The stress responses of the microscale models are then transferred into the macroscale models. The results also prove that the Gamma radiation obviously increases the hardness of the macroscale models. Data comparison shows that the numerical results agree with the testing data well, which verifies the developed method. The present work develops a new method to predict the radiation effects on mechanical properties of rubber foams.