The Effects of the Built Environment on the Mental Health of Older Adults: A Case Study in Hangzhou, China.

Background and Objectives: This study examines the association between the built environment and mental health among older adults by exploring the potential pathways through the perceived built environment, social interaction, and environmental pollution. Research Design and Methods: Research data were collected from 1 405 older adults aged 60 years and older in 30 residential neighborhoods of Hangzhou, China, in 2022. The participants' evaluation of the perceived built environment, social interaction, and environmental pollution were assessed. Mental health was measured by the 12-item Short-Form Health Survey. The built environment was measured through an evaluation of density, diversity, design, destination accessibility, distance to transit, and the age-friendly environment. Structural equation models were established based on 300-m, 500-m, and 800-m buffers from the entrance of residential neighborhoods. The propensity score method was employed for sensitivity analysis. Results: With regard to older adult's mental health, there were significant direct effects of the accessibility of health services, shopping services, and bus stops. A robust mediating effect of perceived built environment was displayed on the relationship between land use mix and mental health of older adults. Social interaction exhibited robust mediating effects between the age-friendly environment, the number of bus stops, and mental health of older adults. Discussion and Implications: This study provides empirical experience for related research on the built environment and mental health as well as policy implications for urban planners focusing on community planning.

Efficient capture of radioactive iodine by ZIF-8 derived porous carbon.

Due to the rapid diffusion of radioactive iodine, the demand for safe and efficient capture and storage of radioactive iodine is increasing worldwide. The use of porous carbon materials to capture iodine has aroused great interest. This work prepared porous carbon materials derived from polymetallic oxides of the zeolitic imidazolate framework (ZIF) by pyrolysis at 1000 °C. The carbon materials (CZIF-1000) have a high specific surface area of about 1110 m2/g and a total pore volume of 0.92 cm3/g. Adsorption studies have shown that the CZIF-1000 had significant adsorption performance for iodine, and the adsorption capacity can reach 790.8 mg/g at 8h. The potential mechanism of adsorption is that the carbonization causes the charge-transfer interaction and pore size distribution. Compared with the conventional adsorbents, the adsorbents showed faster kinetics and high extraction capacity for iodine. This experiment provides an effective method for designing a highly efficient adsorbent for iodine and broadens the ideas for developing new iodine extraction adsorbents.

Transformation details of poly(acrylonitrile) to poly(amidoxime) during the amidoximation process.

During the amidoximation process, transformation details of poly(acrylonitrile) (PAN) to poly(amidoxime) (PAO) is critical for optimizing amidoximation conditions, which determine the physicochemical properties and adsorption capabilities of PAO-based materials. Although the optimization of amidoximation conditions can be reported in the literature, a detailed research on the transformation is still missing. Herein, the effect of the amidoximation conditions (i.e. temperature, time, and NH2OH concentration) on the physicochemical properties and adsorption capabilities of PAO was studied in detail. The results showed that the extent of amidoximation reaction increased with increasing temperature, time, and NH2OH concentration. However, a considerably high temperature (>60 °C) and a considerably long time (>3 h) could result in the degradation and decomposition of PAO's surface topologies and functional groups, and then decrease its adsorption capability for U(vi). The optimal amidoximation condition was 3 h, 60 °C and 50 g L-1 NH2OH. At this condition, the PAO obtained presented the highest adsorption capability for U(vi) under experimental conditions. These results provide pivotal information on the transformation of PAO-based materials during the amidoximation process.

Epoxy graphene oxide from a simple photo-Fenton reaction and its hybrid with phytic acid for enhancing U(VI) capture.

A novel approach to synthesize phytic acid (PA) functionalized graphene oxide (P-pFGO-7) treated by the photo-Fenton reaction has been designed, which has been used as an adsorbent for efficient capture of U(VI) from aqueous solution. The structure and morphology of P-pFGO-7 were characterized well. The adsorption property for P-pFGO-7 was comprehensively assessed by batch experiments, showing the high adsorption capacity (266.7 mg/g, at pH = 4.0, T = 298 K), fast adsorption kinetics (~10 min), good selectivity for U(VI) and Ln-An ions in various coexisting ions and excellent regeneration capacity. With the assistance of various characterization techniques and batch adsorption results, it is found that PA makes the most contribution to coordinate U(VI) heavily depending on the PO moiety. P-pFGO-7 could be regenerated by 0.1 mol/L Na2CO3 with ~95% desorption efficiency and reused well after five recycles. This present work provides a feasible route to modify graphene oxide and extend PA for potentially practical application in the removal of U(VI) from radioactive wastewater.

Aggregation of Silica Nanoparticles in Sol-Gel Processes to Create Optical Coatings with Controllable Ultralow Refractive Indices.

Optical coatings with controllable ultralow refractive indices are of profound significance in optical areas. However, it remains a challenge to fabricate such coatings using a simple method. Here we develop an effective and simple approach to create ultra-low-index coatings. This approach was based on a modified sol-gel process, with a key process that involved the aggregation of silica nanoparticles via the addition of a polymer surfactant (e.g., polyvinylpyrrolydone) in sols before coating. The approach involves three steps: the synthesis of silica sols under ammonia catalysis in ethanol (Stöber method), the addition of polyvinylpyrrolydone in the silica sols to induce the aggregation of the silica nanoparticles, and the formation of ultra-low-index coatings by depositing the aggregated silica sols on substrates. Through varying the aggregation extent, this approach produced coatings with controllable refractive indices ranging from 1.17 to 1.07. To the best of our knowledge, the minimum index value of 1.07 from our coating is among the lowest refractive indices ever reported. The ultra-low-index coatings demonstrated excellent optical properties, with which perfect quarter-wavelength antireflection coatings (maximum transmittance ∼100%) and broadband antireflection coatings (transmittance >98% from 400 to 1100 nm) can be prepared. One advantage of the antireflection coatings is that their transmission is less dependent on the refractive index and the thickness of the stacking layer, which make it promising in large-scale production. Moreover, the coatings can be made hydrophobic (water contact angle 136°) by exposing the coatings to a hexamethyldisilazane atmosphere, exhibiting high environmental stability in a humid environment. The aggregation of silica nanoparticles in sol-gel processes provides a scalable alternative to the current approaches for creating ultra-low-index coatings.

Controlled Growth of Ultra-Thick Polymer Brushes via Surface-Initiated Atom Transfer Radical Polymerization with Active Polymers as Initiators.

Polymer brushes exhibit functionalities useful for a large number of applications. Often these functionalities only emerge when the polymer brushes have a desired thickness. Here, a significant breakthrough is achieved in the synthesis of ultra-thick polymer brushes using polymer initiators in the approach of surface-initiated atom transfer radical polymerization, yielding polymer brushes with a controllable thickness up to 15.1 µm. This is reportedly the thickest polymer brush ever synthesized. This approach is applicable for several monomers such as acrylonitrile, methyl acrylate, and styrene, and for other types of polymer substrates such as fibers.

Rapid immobilization of simulated radioactive soil waste by microwave sintering.

A rapid and efficient method is particularly necessary in the timely disposal of seriously radioactive contaminated soil. In this paper, a series of simulated radioactive soil waste containing different contents of neodymium oxide (3-25wt.%) has been successfully vitrified by microwave sintering at 1300°C for 30min. The microstructures, morphology, element distribution, density and chemical durability of as obtained vitrified forms have been analyzed. The results show that the amorphous structure, homogeneous element distribution, and regular density improvement are well kept, except slight cracks emerge on the magnified surface for the 25wt.% Nd2O3-containing sample. Moreover, all the vitrified forms exhibit excellent chemical durability, and the leaching rates of Nd are kept as ∼10-4-10-6g/(m2day) within 42days. This demonstrates a potential application of microwave sintering in radioactive contaminated soil disposal.

Ultralow-refractive-index optical thin films through nanoscale etching of ordered mesoporous silica films.

A great deal of intensive research has been conducted to obtain high-quality transparent ultralow-refractive-index and ultralow-dielectric-constant thin films for microptics and microelectronics applications. Here, we report a simple procedure to prepare highly porous silica thin films with high optical quality and water resistance through nano-etching of mesoporous silica films followed by fluoroalkylsilane surface modification. The films possess an ultralow refractive index of 1.03 (800 nm) and an ultralow dielectric constant of 1.30 (100 kHz), to our knowledge the lowest values ever reported in thin film materials. The films are superhydrophobic (water contact angle=156 deg), thus exhibit high moisture stability.