Effect of Additives on the Cloud Point Temperature of 2‑Hydroxy-3-isopropoxypropyl Starch Solutions

Temperature-responsive polymers with a lower critical solution temperature (LCST) have attracted much attention in biomedical and biotechnological fields. It is important to tune their cloud point temperature (<i>T</i>_<i>c</i>) in a broad temperature range as desired by the applications. In this study, new thermo-responsive 2-hydroxy-3-isopropoxypropyl starches (HIPS) was synthesized using Hylon V starch as raw material and isopropyl glycidyl ether as hydrophobic reagent. The phase transition behavior of HIPS and their <i>T</i>_<i>c</i> were determined by spectrophotometry. The effects of several conditions on the <i>T</i>_<i>c</i> of the HIPS were also investigated, which indicated that varying the molar substitution (MS) of HIPS can adjust <i>T</i>_<i>c</i> in a broad temperature range from 69 to 28 °C by changing the hydrophobic–hydrophilic balance of starch. The phase transition became fast and the <i>T</i>_<i>c</i> decreased with increasing polymer concentration. The effect of a series of sodium salts on the <i>T</i>_<i>c</i> of aqueous HIPS solutions was reported and the effectiveness of ions follows a trend, known as Hofmeister series. Several organic solvents were selected and the organic additives with small molecular weight can also regulate the <i>T</i>_<i>c</i> of HIPS in a certain range by changing the polymer–water interactions

SnO₂ Inverse Opal Composite Film with Low-Angle-Dependent Structural Color and Enhanced Mechanical Strength

Structural colors are attracting considerable attention for their advantages of environmental friendliness and resistance to fading. However, the weak mechanical strength and intrinsic iridescent color restrict their widespread application. This article describes a SnO₂ inverse opal composite film with low-angle-dependent structural color and enhanced mechanical strength. In the present study, a direct template method was used to prepare SnO₂ inverse opals, which were then embedded in polydimethylsiloxane (PDMS). The structural colors of obtained composite films were low-angle-dependent due to light scattering and high effective refractive index. Meanwhile, because of the good physical strength of PDMS, structures of SnO₂ inverse opals were provided with effective protection. No specific wavelength shift occurred during stretching, and exhibited excellent cycling stability. All these advantages indicated potential applications in packing and decorating materials

Structural Color Patterns on Paper Fabricated by Inkjet Printer and Their Application in Anticounterfeiting

Inkjet-printed structural color patterns have attracted great attention in recent years because of their broadly promising applications. However, the patterns are usually fabricated on pretreated plastic substrates. Herein a convenient inkjet printing method was developed to fabricate large-scale computer-designed structural color patterns on photo paper without any treatment using inks containing monodisperse CdS spheres. By this strategy, not only were the single-color and multicolor structural color patterns on paper successfully obtained, but also invisible photonic anticounterfeiting was achieved without any external stimuli. The key point of this anticounterfeiting technique is printing patterns and the background with inks containing uniformed CdS spheres with different diameters but similar intrinsic colors, so that the invisible patterns can be observed clearly by simply changing the viewing angle. The invisible and visible can be realized without the change of intrinsic structure, and the patterns are all solids. The patterns will have long lifetime and good durability, which is beneficial for their practical usage

Structural Color Patterns on Paper Fabricated by Inkjet Printer and Their Application in Anticounterfeiting

Inkjet-printed structural color patterns have attracted great attention in recent years because of their broadly promising applications. However, the patterns are usually fabricated on pretreated plastic substrates. Herein a convenient inkjet printing method was developed to fabricate large-scale computer-designed structural color patterns on photo paper without any treatment using inks containing monodisperse CdS spheres. By this strategy, not only were the single-color and multicolor structural color patterns on paper successfully obtained, but also invisible photonic anticounterfeiting was achieved without any external stimuli. The key point of this anticounterfeiting technique is printing patterns and the background with inks containing uniformed CdS spheres with different diameters but similar intrinsic colors, so that the invisible patterns can be observed clearly by simply changing the viewing angle. The invisible and visible can be realized without the change of intrinsic structure, and the patterns are all solids. The patterns will have long lifetime and good durability, which is beneficial for their practical usage

Multiple Colors Output on Voile through 3D Colloidal Crystals with Robust Mechanical Properties

Distinguished from the chromatic mechanism of dyes and pigments, structural color is derived from physical interactions of visible light with structures that are periodic at the scale of the wavelength of light. Using colloidal crystals with coloring functions for fabrics has resulted in significant improvements compared with chemical colors because the structural color from colloidal crystals bears many unique and fascinating optical properties, such as vivid iridescence and nonphotobleaching. However, the poor mechanical performance of the structural color films cannot meet actual requirements because of the weak point contact of colloidal crystal particles. Herein, we demonstrate in this study the patterning on voile fabrics with high mechanical strength on account of the periodic array lock effect of polymers, and multiple structural color output was simultaneously achieved by a simple two-phase self-assembly method for printing voile fabrics with 3D colloidal crystals. The colored voile fabrics exhibit high color saturation, good mechanical stability, and multiple-color patterns printable. In addition, colloidal crystals are promising potential substitutes for organic dyes and pigments because colloidal crystals are environmentally friendly

Targeted Synthesis of “Urechis Unicinctus”-Like Nitrogen-Doped Porous Carbon Nanorods for Supercapacitors

Functionalized carbon nanorods have attracted extensive attention in materials science and technology, due to their unique structure and excellent properties. Nevertheless, it remains a huge challenge to develop an approach that combines simple, cost-effective implementation paths with outstanding target products. Herein, we propose a soft-template strategy to achieve directional preparation of one-dimensional (1D) “urechis unicinctus”-like nitrogen-doped porous carbon nanorods with abundant nitrogen content (8.35 wt %), high surface area (2560 m2/g), and hierarchical pore structure. The anionic surfactant sodium bis(2-ethylhexyl) sulfosuccinate (AOT) and melamine are the template agent and main carbon–nitrogen precursor, respectively. By controlling the amount of ammonia (NH4OH), the behavior of AOT molecules in the aqueous phase can be accurately interfered to construct rodlike micellar templates, thereby guiding the preparation of target structural products. The rationality and stability of the original route were verified by the rigorous control experiments and relevant characterization. Moreover, the prepared materials show excellent performance in the evaluation of supercapacitors with an outstanding specific capacitance of 398 F/g at a current density of 0.5 A/g and 73.4% of original specific capacitance retention at a current density of 20 A/g

Normalizing Tumor Blood Vessels to Improve Chemotherapy and Inhibit Breast Cancer Metastasis by Multifunctional Nanoparticles

The abnormal tumor blood vessels with high leakage can promote tumor cells to infiltrate into the systemic circulation and increase the risk of tumor metastasis. In addition, chemotherapy may destroy tumor blood vessels and further aggravate metastasis. Normalizing tumor blood vessels can reduce vascular leakage and increase vascular integrity. The simultaneous administration of vascular normalization drugs and chemotherapy drugs may resist the blood vessels’ destruction of chemotherapy. Here, multifunctional nanoparticles (CCM@LMSN/DOX&St), which combined chemotherapy with tumor blood vessel normalization, were prepared for the treatment of breast cancer. The results showed that CCM@LMSN/DOX&St-loaded sunitinib (St) promoted the expression of junction proteins Claudin-4 and VE-cadherin of endothelial cells, reversed the destruction of DOX to the endothelial cell layer, protected the integrity of the endothelial cell layer, and inhibited the migration of 4T1 tumor cells across the endothelial cell layer. In vivo experiments showed that CCM@LMSN/DOX&St effectively inhibited tumor growth in situ; what is exciting was that it also inhibited distal metastasis of breast cancer. CCM@LMSN/DOX&St encapsulated with St can normalize tumor blood vessels, reverse the damage of DOX to tumor blood vessels, increase the integrity of blood vessels, and prevent tumor cell invasion into blood vessels, which can inhibit breast cancer spontaneous metastasis and reduce chemotherapy-induced metastasis. This drug delivery platform effectively inhibited the progression of tumors and provided a promising solution for effective tumor treatment

General Method to Synthesize Highly Stable Nanoclusters via Pickering-Stabilized Microemulsions

The ability to not only control but also maintain the well-defined size of nanoclusters is key to a scientific understanding as well as their practical application. Here, we report a synthetic protocol to prepare and stabilize nanoclusters of different metals and even metal salts. The approach builds on a Pickering stabilization effect inside a microemulsion system. We prove that the emulsion interface plays a critical role in the formation of nanoclusters, which are encapsulated in situ into a silica matrix. The resulting nanocapsule is characterized by a central cavity and a porous shell composed of a matrix of both silica and nanoclusters. This structure endows the nanoclusters simultaneously with high thermal stability, good biocompatibility, and excellent photostability, making them well suited for fundamental studies and practical applications ranging from materials chemistry, catalysis, and optics to bioimaging

Highly Efficient Pt Decorated CoCu Bimetallic Nanoparticles Protected in Silica for Hydrogen Production from Ammonia–Borane

Pt decorated CoCu bimetallic nanoparticles (NPs) coated by silica (Pt-CoCu@SiO₂) were synthesized for efficient catalytic hydrogen production from hydrolysis of ammonia–borane (NH₃·BH₃; AB). Initially, silica-coated CoCu bimetallic NPs (CoCu@SiO₂) were prepared by a modified co-reduction method from reverse microemulsion. Further, Pt-CoCu@SiO₂ was obtained by a facile spontaneous displacement reaction by using CoCu@SiO₂ and H₂PtCl₆ as the starting materials. The catalytic activity of Pt on bimetallic support was compared to that of monometallic supports, i.e., Co and Cu. The results of catalytic experiments showed that the support of CoCu bimetal can significantly enhance the activity of Pt as compared to that of pure Cu or Co. An impressive turnover frequency (TOF) value of 272.8 mol_H2 mol_Pt^–1 min^–1 was achieved at the hydrolysis temperature of 30 °C for Pt-CoCu@SiO₂. The detailed formation process of catalysts was described, and the samples were characterized by TEM, STEM, XPS, EDS element mapping, etc