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In situ photodeposition of MoO3−x with oxygen vacancies evoked synergistic photo-thermal catalytic CO2 reduction over g-C3N4.

A completely confluent endothelial cell (EC) monolayer is required to maintain proper vascular function in small diameter tissue-engineered vascular graft (TEVG). However, the most effective method for EC attachment to the luminal surface and formation of an entire endothelium layer that works in vitro remains a complicated challenge that requires urgent resolution. Although pulsatile flow has been shown to be better suited for the generation of functional endothelium, the optimal frequency setting is unknown. Several pulsatile flow frequencies were used to implant rat bone mesenchymal stem cells (MSC) into the lumen of decellularized porcine carotid arteries. The endothelium's integrity and cell activity were investigated in order to determine the best pulse frequency settings. The results showed that MSC were maximally preserved and exhibited maximal morphological changes with improved endothelialization performance in response to increased pulse stimulation frequency. Increased pulse frequency stimulation stimulates the expression of mechanoreceptor markers, cytoskeleton reorganization in the direction of blood flow, denser skeletal proteins fibronectin, and stronger intercellular connections when compared to constant pulse frequency stimulation. MSC eventually develops an intact endothelial layer with anti-thrombotic properties on the inner wall of the decellularized tubular lumen. Conclusion: The decellularized vessels retain the three-dimensional structure of the vasculature, have a surface topography suitable for MSC growth, and have good mechanical properties. By increasing the frequency of pulsed stimulation, MSC endothelialize the lumen of the decellularized vasculature. It is expected to have anti-thrombotic and anti-neointimal hyperplasia properties after implantation, ultimately improving the patency of TEVG.

Here, we report (C4H9)4NCuCl2 single crystals with a luminous intensity that remains largely the same after soaking in water for 24 h. (CH9)4NCuCl2 has a new type zero-dimensional framework, in which the isolated [CuCl2]- anions are wrapped by organic (C4H9)4N+ cations. As expected, (C4H9)4NCuCl2 shows a broad emission band at 508 nm with a photoluminescence quantum yield of approximately 82% at room temperature, stemming from self-trapped exciton (STE) emission. Temperature-dependent photoluminescence measurement reveals that there is an energy barrier ΔE (24.0 meV) between the intrinsic state and STE state, which leads to the increase in emission intensity with an increase in temperature (98-278 K), while the emission intensity begins to decrease when the temperature is higher than 278 K due to the effects of both thermal quenching and carrier scattering. Our findings provide a new idea for the design of lead-free anti-water stability metal halide materials.

Rapid endothelialization is crucial for in situ tissue engineering vascular grafts to prevent graft failure in the long-term. Gelatin is a promising nature material that can promote endothelial cel...

Tissue engineering is thought to the most promising strategy to develop successful small diameter vascular grafts (SDVG) to meet clinical demand. The introduction of natural substances into the SDVG made from synthetic biomaterials can improve the biocompatibility to promote the regeneration of SDVG in vivo. Due to that natural materials from different sources may have property deviation, it is vital to determine the source of natural materials to optimize SDVG fabrication for tissue engineering applications. In this study, bioactive SDVGs were prepared via coating of heparin-modified poly-(ε-caprolactone) scaffolds with a precursor solution containing vascular extracellular matrix (VECM) components and subsequent in situ gelation. The mechanical properties, degradation behaviors, and morphologies of the SDVGs were thoroughly characterized and evaluated. Cell experiments demonstrated the in vitro tissue specificity of the VECM that could promote the proliferation of endothelial cells better than skin-derived collagen. Furthermore, three types of SDVGs, SDVGs with blank hydrogel, SDVGs with skin-derived collagen, and SDVGs with vascular extracellular matrix (VECM-SDVGs), were implanted into the abdominal aorta of rats for one month. The explanted SDVGs were then comprehensively evaluated using hematoxylin and eosin, Masson, von Kossa staining, and immunohistochemical staining for CD31, α-SMA, and MHC. The results showed that the VECM-SDVGs showed the best endothelium regeneration, appropriate intima regeneration, and no calcification, indicating the in vivo specificity of the fabricated VECM-SDVGs. Thus, long-term implantation of VECM-SDVGs was performed. The results showed that a complete endothelial layer formed after 6 months of implantation, and the amount of contractile SMCs in the regenerative smooth muscle layer approached the amount of native aorta at the 12th month. Consequently, relying on vascular tissue specificity, VECM-SDVGs can modulate the regenerative behavior of the implanted SDVGs in vivo to achieve satisfactory vascular regeneration both in short- and long-term implantation.

Recently, zero-dimensional (0D) metal halides have made remarkable achievements in the field of optoelectronics due to their diverse structures and optical performances. Here, we report 0D (TBA)2Cu2I4 (TBA+ = tetrabutylammonium cation) single crystals (SCs), which shows a dual-emission band at 473 and 699 nm and a bright cool-white emission with a high photoluminescence quantum yield (PLQY) of 72.5% at room temperature (RT). The temperature-dependent emission spectra and Raman spectra show that a dual self-trapped exciton (STE) is present in this compound, and the external thermal energy can effectively regulate the population of STEs in the two emitting states, and thus the emission color can be changed from blue at a low temperature (78 K) to a cool-white emission at RT. More specifically, (TBA)2Cu2I4 SCs possess high anti-water stability, and can maintain highly efficient emission even if immersed in water for 24 hours. Also noteworthily, the high thermal stability, air stability and photostability of this component have also been proved.

Low-dimensional organic–inorganic hybrid metal halides have drawn intense attention due to their flexible structures and outstanding optical properties. However, the toxicity of lead halides hinders their future application in optoelectronic devices. Herein, we report a zero-dimensional (0D) lead-free compound of (TPA)2SbCl5 (TTA+ = tetrapropylammonium cation) single crystals (SCs), which crystallizes in a triclinic system with P symmetry. Interestingly, (TPA)2SbCl5 exhibits a single broad orange emission band at 610 nm under low-energy excitation (e.g., 375 nm) with a high photoluminescence quantum yield (PLQY) of 95.3%, while it shows a dual-band emission profile with an additional narrow emission band at 466 nm at high-energy excitation (e.g., 300 nm), which is formed by the transformation of the doublet of spin–orbit interactions into two individual STEs. The Raman spectra supplied clear evidence for the self-trapped exciton (STE) with clear multiphonon modes in (TPA)2SbCl5, which reflects its strong nonlinear electron–phonon coupling. The emission mechanism for the temperature-dependent dual emission can be attributed to the radiative transitions of singlet STEs and triplet STEs in [SbCl5]2− clusters. Moreover, a white-light-emitting diode (WLED) was also fabricated by mixing (TPA)2SbCl5 with green (Ba2SiO4:Eu2+) and blue (BaMgAl10O17:Eu2+) phosphors, which exhibited CIE coordinates of (3.48, 3.50), a correlated color temperature (CCT) of 4900 K, and a color rendering index (CRI) of 93.2. Our achievements illustrate that the lead-free compound of (TPA)2SbCl5 has great potential in solid-state lighting.

Decellularization is a promising approach in tissue engineering to generate small-diameter blood vessels. However, some challenges still exist. We performed two decellularization phases to develop an optimal decellularized scaffold and analyze the relationship between the extracellular matrix (ECM) composition and mechanical properties. In decellularization phase I, we tested sodium dodecylsulfate (SDS), Triton X-100 (TX100) and trypsin at different concentrations and exposure times. In decellularization phase II, we systematically compared five combined decellularization protocols based on the results of phase I to identify the optimal method. These protocols tested cell removal, ECM preservation, mechanical properties, and residual cytotoxicity. We further immobilized heparin to optimal decellularized scaffolds and determined its anticoagulant activity and mechanical properties. The combined decellularization protocol comprising treatment with 0.5% SDS followed by 1% TX100 could completely remove the cellular contents and preserve the mechanical properties and ECM architecture better. In addition, the heparinized decellularized scaffolds not only had sustained anticoagulant activity, but also similar mechanical properties to native vessels. In conclusion, heparinized decellularized scaffolds represent a promising direction for small-diameter vascular grafts, although further

Solving partial differential equations (PDEs) is an important research means in the fields of physics, biology, and chemistry. As an approximate alternative to numerical methods, PINN has received extensive attention and played an important role in many fields. However, PINN uses a fully connected network as its model, which has limited fitting ability and limited extrapolation ability in both time and space. In this paper, we propose PhyGNNet for solving partial differential equations on the basics of a graph neural network which consists of encoder, processer, and decoder blocks. In particular, we divide the computing area into regular grids, define partial differential operators on the grids, then construct pde loss for the network to optimize to build PhyGNNet model. What's more, we conduct comparative experiments on Burgers equation and heat equation to validate our approach, the results show that our method has better fit ability and extrapolation ability both in time and spatial areas compared with PINN., Comment: there some errors in method describtion

Increasingly growing problems in vascular access for long-term hemodialysis lead to a considerable demand for synthetic small diameter vascular prostheses, which usually suffer from some drawbacks and are associated to high failure rates. Incorporating the concept of in situ tissue engineering (TE) into synthetic small diameter blood vessels, for example, thermoplastic poly(ether urethane) (TPU) ones, could provide an alternative approach for vascular access that profits from the advantages of excellent mechanical properties of synthetic polymer materials (early cannulation) and unique biointegration regeneration of autologous neovascular tissues (long-term fistulae). In this study, a kind of heparinized small diameter (d = 2.5 mm) TPU/poly(ε-caprolactone) (TPU/PCL-Hep) bi-layered blood vessels was electrospun with an inner layer of PCL and an outer layer of TPU. Afterward, the inner surface heparinization was conducted by coupling H

Due to the effects of electron correlation and spin–spin coupling, pure transition metal compounds rarely produce luminescence and ferromagnetism. In this work, the Pb-free perovskite materials, C8H20N2MnBr4 and C4H10NMnBr3 with high luminescence yields, were obtained via a simple mechanochemical process. In C8H20N2MnBr4 powders, MnBr42− coordinated with two pyrrolidine molecules to form an independent mononuclear structure in a crystal, with paramagnetic properties and a strong emission band at 520 nm due to the lowest d–d crystal field radiation transition for individual Mn(II) ions. In C4H10NMnBr3 powders, MnX64− octahedra, coordinated with a much smaller amount of pyrrolidine molecules than that in C8H20N2MnBr4, formed edge-sharing linear chains of Mn-ion octahedra with a much smaller Mn–Mn distance, which produced emission bands at 628 nm due to the ferromagnetic coupling of Mn pairs or clusters. Influenced by the modification in the local crystal structure by incorporated pyrrolidine molecules, the microcrystals in these two powders exhibited different phase transition temperatures and varied lifetimes in their photoluminescence besides their emission colors. By controlling the processing time of mechanochemical reactions and pyrrolidine amount, the pyrrolidine insertion into the lattice of this transition metal halide can be adjusted to be completely realized, which provides a very simple way to change the ligand from a halide ion to an organic molecule, which regulates the Mn–Mn distance in the lattice, modifying the electronic correlation and spin coupling, thereby obtaining new manganese perovskite compounds with both strong luminescence and clear ferromagnetic properties.

A lead-free compound, (TBAC)SnCl3 (TBAC = tetrabutylammonium chloride), with high anti-water stability was reported, which can be stable in water for 24 hours. Upon photoexcitation, this compound exhibits a green photoluminescence (PL) centered at 523 nm with a larger Stokes shift of 260 nm at room temperature (RT), stemming from self-trapped exciton (STE) emission.

Here, we report (C

The efficient utilization of near-infrared (NIR) light for photocatalytic hydrogen generation is vitally important to both solar hydrogen energy and hydrogen medicine, but remains a challenge at present, owing to the strict requirement of the semiconductor for high NIR responsiveness, narrow bandgap, and suitable redox potentials. Here, an NIR-active carbon/potassium-doped red polymeric carbon nitride (RPCN) is achieved for by using a similar-structure dopant as the melamine (C

Rapid endothelialization is crucial for

A novel recombinant human-like collagen/fibroin scaffold has been prepared previously, which has high porosity, controllable pore size, and much better mechanical properties than the reported fibroin-based scaffold. In this research, the cell responses of vascular smooth muscle cells to this blend scaffold were examined in vitro. Cell morphology, adherence, and growth in scaffolds were observed by scanning electron microscopy, laser scanning confocal microscopy after staining of the cells with propidium iodide at 1, 3, 5, and 7 days, respectively. A wide range of measurements, including 3-[4,5–dimethylthiazol-2-yl]-2, 5-diphenyl tetrasodium bromide assay, and total intracellular protein content at the end of 7 days culture, were conducted. An increase of viability and protein content of vascular smooth muscle cells cultured in recombinant human-like collagen/fibroin scaffold was found. The laser scanning confocal microscopy and scanning electron microscopy results confirm that the cells readily adhered and proliferation in the blend than in fibroin scaffold, and indicate a better adhesion process. The positive effects were especially significant for vascular smooth muscle cells. The recombinant human-like collagen/fibroin scaffold could be a promising biomaterial for vascular tissue engineering.

Establishing effective non-platinum active sites on polymeric carbon nitride (PCN) remains a great demanding to achieve highly efficient photocatalytic hydrogen generation performance. Modification with molecular complex catalysts on PCN skeletons has been demonstrated as a promising strategy. Herein, hybrid photocatalytic material was successfully synthesized by modifying PCN with copper molecular ligand (CuL, Schiff-based copper complex) via π-π stacking. Interestingly, atomically dispersed Cu is formed in CuL/PCN. Compared to PCN, the π-π stacking in CuL/PCN is beneficial for facilitating the migration of photogenerated electrons from PCN to CuL. Furthermore, photo-redox ability of the atomically dispersed Cu is regulated by the ligand (Schiff base) in CuL and the introduction of CuL provides abundant active sites to capture the photogenerated electrons, whereby the reductive reaction of H2O/H+ to H2 for CuL/PCN was significantly promoted. Consequently, an optimal hydrogen evolution rate of 15.90 μmol·h−1 was obtained on 3CuL/PCN, which was 2.02 times higher than that of 3.0 wt% Pt/PCN (7.86 μmol·h−1). More importantly, the hybrid material exhibits an outstanding conversion efficiency (90 %) and selectivity (99 %) for α-methylation of ketones by making full use of the in-situ generated H species and photogenerated holes under visible light irradiation.

The efficient utilization of near-infrared (NIR) light for photocatalytic hydrogen generation is vitally important to both solar hydrogen energy and hydrogen medicine, but remains a challenge at present, owing to the strict requirement of the semiconductor for high NIR responsiveness, narrow bandgap, and suitable redox potentials. Here, an NIR-active carbon/potassium-doped red polymeric carbon nitride (RPCN) is achieved for by using a similar-structure dopant as the melamine (C3 H6 N6 ) precursor with the solid KCl. The homogeneous and high incorporation of carbon and potassium remarkably narrows the bandgap of carbon nitride (1.7 eV) and endows RPCN with a high NIR-photocatalytic activity for H2 evolution from water at the rate of 140 µmol h-1 g-1 under NIR irradiation (700 nm ≤ λ ≤ 780 nm), and the apparent quantum efficiency is high as 0.84% at 700 ± 10 nm (and 13% at 500 ± 10 nm). A proof-of-concept experiment on a tumor-bearing mouse model verifies RPCN as being capable of intratumoral NIR-photocatalytic hydrogen generation and simultaneous glutathione deprivation for safe and high-efficacy drug-free cancer therapy. The results shed light on designing efficient photocatalysts to capture the full spectrum of solar energy, and also pioneer a new pathway to develop NIR photocatalysts for hydrogen therapy of major diseases.

In this work, a novel lignin/titanium dioxide (QAL/TiO2) hybrid composite with regular microstructure and synergistically enhanced UV absorption properties was synthesized by a simple hydrothermal method using lignin and butyl titanate. The prepared QAL/TiO2 composite is hybrid structure in which lignin and TiO2 is uniformly embedded, and has strong chemical bond bonding force. The QAL/TiO2 hybrid composite particles were used for doping modification of waterborne polyurethane (WPU), which had good interfacial compatibility and dispersibility in WPU. The obtained WPU + QAL/TiO2 film shows excellent UV shielding performance and great mechanical properties, the tensile strength and elongation at break are significantly improved compared with pure WPU film. And it also has excellent anti-UV aging property, that the mechanical performance basically remains unchanged after 96 h of high power ultraviolet irradiation. This work not only provides a kind of lignin/TiO2 hybrid composite with neat structure, good dispersion and excellent optical properties, but also has great significance for the high-valued utilization of biomass resources.

On this basis, a novel recombinant human-like collagen (RHLC)/silk fibroin scaffold material with high porosity and controllable aperture was prepared. The compatibility of osteoblasts (OB) with the blends was tested in vitro. The morphology, adhesion and growth of scaffold cells were observed by scanning electron microscope and laser confocal microscope. Extensive measurements, including 3-[4, 5-dimethylthiazole-2-acyl]-2, 5-diphenyl tetrabrominate assays, intracellular total protein content, and alkaline phosphatase activity assays were performed after 7 days of culture. Survival and protein content increased in RHLC/fibroin stents. LSCM and SEM results confirmed that the cells grew better in the mixed scaffolds than in the pure silk scaffolds, and showed that the cells were easy to adhere and diffuse in the RHLC/silk scaffolds. RHLC/silk fibroin scaffolds are promising biomaterials for bone tissue engineering.

We describe a facile route to the development of novel robust non-carbon titanium cobalt nitride (Ti0.9Co0.1N) used as a support for Pt, and the catalyst exhibits high activity and stability for the oxygen reduction reaction (ORR). XRD and TEM results show that the synthesized Ti0.9Co0.1N is formed as a single-phase solid solution with high purity. The XPS measurements verified the strong metal/support interaction between Pt nanoparticles (NPs) and the Ti0.9Co0.1N support. Most importantly, Ti0.9Co0.1N supported Pt catalyst (Pt/Ti0.9Co0.1N) exhibits a much higher mass activity and durability than that of the commercial JM Pt/C electrocatalyst for ORR. The accelerated durability test (ADT) reveals that the novel Ti0.9Co0.1N support can dramatically enhance the durability of the catalyst and maintain the electrochemical surface area (ECSA) of Pt. Pt/Ti0.9Co0.1N shows great improvement in ECSA preservation, with only 35% of the initial ECSA drop even after 10 000 ADT cycles. The experimental data indicate that the electronic structure of Pt can be modified by Co doping, and there exists a strong interaction between Pt and the Ti0.9Co0.1N support, both of them are playing an important role in improving the activity and durability of the Pt/Ti0.9Co0.1N catalyst.

In the field of 3D vision measurement, surface structured light measurement is a new active technology, which can be widely used in the field of non-contact 3D modeling. Through the analysis of the mathematical model of the surface structured light system, a key point for the accuracy of 3D measurement is whether the spatial coordinates of pixels in encoding patterns can be accurately obtained, which is also the standard to judge the quality of coding method. Therefore, the paper adopts a coding method combining Gray code with Phase-Shift patterns. Simultaneously, a 3D vision measurement system composing a single digital camera and a single digital projector is constructed. This method is proved not only to improve the accuracy of 3D measurement, but also to be more efficient than only Gray coding method, which is apt in oil painting scanning with 3D reproduction, incomplete cultural relic’s repair and construction of 3D geological model etc.

Hydrogel is a kind of three-dimensional network polymer formed by chemical bond or physical cross-linking. It is widely used in the field of biomaterial because of its good biocompatibility. In this experiment, a gel-based composite material for 3D bioprinting was prepared using hyaluronic acid-methyl cellulose (HAMC) gel as carrier and nano-hydroxyapatite/collagen (nHAC). The effects of gel formulation on gel process were analyzed by in vitro gel test, rheological analysis, in vitro degradation and scanning electron microscopy. The results showed that HAMC with different mineralized collagen concentration could be rapidly gelatinized at 37 °C within 3 min. The rheological experiments showed that the HAMC-mineralized collagen had shear thinning properties suitable for 3D bioprinting. The results showed that the degradation rate was similar in the first 10 days, but the degradation rate was slower with the increase of mineralized collagen concentration. The porous structure and high porosity of the hydrogel were observed by scanning electron microscopy (SEM). The porous structure of the cross-linked sample was better.

Recently, the incidence of cardiovascular disease, which is mainly represented by myocardial infarction and cerebral infarction, is increasing, the corresponding surgical also showed an upward trend. Only X-ray irradiation could not accurately determine the location of the three-dimensional position of the patient, which would cause some difficulties in the efficiency of surgery and the implants continued positioning. Screen printing with a wide range of applications, ink layer coverage, cheap, easy to control the characteristics of technology, can be widely used in various fields. This experiment focuses on the development of an ink using for screen printing which could be developed under X-ray. And this ink could be applied for medical measurement tape, so as to improve the accuracy and efficiency of the operation.

Titanium molybdenum nitride (Ti0.8Mo0.2N) hybrid support is prepared by a facile and efficient method, including a one-pot solvothermal process followed by a thermal treatment under ammonia at 750 °C, and this hybrid support is further decorated with Pt nanoparticles to catalyze the oxidation of methanol. The catalyst is characterized by X-ray diffraction (XRD), nitrogen adsorption/desorption, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and electrochemical measurements. XRD and TEM results show that the synthesized Ti0.8Mo0.2N is formed as a single-phase solid solution with high purity. Notable, Ti0.8Mo0.2N supported Pt catalyst exhibits a much higher mass activity and durability than that of the conventional Pt/C (E-TEK) electrocatalysts for methanol electrooxidation. The experimental data indicates that the Mo doping has the bifunctional effect that improves the performance and durability of the supported Pt NPs by inducing both co-catalytic and electronic effects.

By the combination of solvothermal alcoholysis and post-nitriding method, titanium nitride nanotubes (TiN NTs), with high surface area, hollow and interior porous structure are prepared successfully and used at a support for Pt nanoparticles. The TiN NTs supported Pt (Pt/TiN NTs) catalyst displays enhanced activity and durability towards methanol oxidation reaction (MOR) compared with the commercial Pt/C (E-TEK) catalyst. X ray diffraction (XRD), nitrogen adsorption/desorption, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) measurements are performed to investigate the physicochemical properties of the synthesized catalyst. SEM and TEM images reveal that the wall of the TiN NTs is porous and Pt nanoparticles supported on the dendritic TiN nanocrystals exhibit small size and good dispersion. Effects of inherent corrosion-resistant, tubular and porous nanostructures and electron transfer due to the strong metal–support interactions of TiN NTs contribute to the enhanced catalytic activity and stability of Pt/TiN NTs towards the MOR.

Al–F co-doped ZnO (AFZO) nanocrystals were successfully synthesized onto glass substrates by the sol–gel method and the structure and morphology of the films as a function of annealing temperature were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results indicated that all the films were polycrystalline with a hexagonal wurtzite structure and exhibited a c-axis preferred orientation. The XPS study confirmed that co-doping ions are successfully incorporated into the ZnO nanostructure. AFZO thin films annealed at 500 °C exhibited the lowest resistivity due to the higher carrier concentration and mobility. The knowledge acquired in this work is important for the AFZO thin films with applications in optoelectronic devices.

A created 3D model based on the scanned point cloud data of an object is usually incomplete owing to low ambient lightness or insufficient reflectivity on the surface when scanning. The paper suggested an AFPF (Advancing Front Patch Feature) method for model’s repair. In this method, the collected point cloud data are divided into orderly 3D volume element sets, called Octree nodes, which are deployed using Octree Data Structure. The nodes’ total number changes with a threshold setting, which is helpful to create optimized curved surface. If some holes appear on the curved surface, characteristics of the holes’ boundary are utilized to determine their position. With the calculation of angles between any two adjacent edges of a polygon hole and the average edge length, the holes could be repaired by inserting triangle vertices accurately. The method is proved not only to make the created model complete, but also to be more efficient than some other algorithms, which will be apt in the fields of cultural relic’s repair, plastic surgery and construction of 3D geological model etc.

Hydroxyapatite and collagen are mainly inorganic and organic components of human natural bone. Nanocrystal hydroxyapatite/collagen (nHAC) composite has good biological properties, and polylactide (PLA) is a biodegradable polymer material. Both can be well applied to organism and play a critical role in bone tissue engineering materials. In this paper, a new nano-hydroxyapatite/collagen/PLA composite with the thought of bionics as raw material of filament for fused deposition modeling (FDM) processes was developed in order to observe the thermal structure properties of the new filaments. The structure and components of the samples were investigated by energy dispersive spectrograph (EDS), X-ray powder diffraction (XRD), Scanning Electronic Microscopy (SEM) and Fourier transform infrared (FTIR). The results of FTIR and XRD showed that the nHAC/PLA changed greatly at 220 and 240 °C compared with the room temperature. And SEM and EDS showed that nHAC/PLA had a complete microstructure and components at 200 °C.

Urchin-like zinc oxide nanoparticles (ZnO NPS) were synthesized by a simple hydrothermal process as a function of various reaction times without any additional surfactant or catalytic agent. The structures of ZnO NPS were characterized by X-ray diffraction (XRD) and a scanning electron microscope (SEM). The XRD results revealed that ZnO powders have a wurtzite structure and the SEM images indicated that ZnO NPS were self-assembled. Optical properties of the ZnO structures were investigated by room-temperature photoluminescence (PL) spectroscopy, and the spectra of these samples exhibited a strong UV band and a negligible green band. With increasing reaction times, the dominated strong UV emission peak centered at 437 nm was obtained, indicating an excellent optical quality of urchin-like ZnO nanocrystals.