Integration of wastewater treatment units and optimization of waste residue pyrolysis conditions in the brominated phenol flame retardant industry

Shiqi Liu,Xiangting Hou,Chengze Yu,Xiangrui Pan,Junhao Ma,Guocheng Liu,Chengzhi Zhou,Yanjun Xin,Qinghua Yan 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.115 No.-

Among the bromine flame retardants, tetrabromobisphenol A (TBBPA) is a highly effective flame retardantthat can be used as both reactive and additive. However, the synthesis reaction of TBBPA has alow conversion rate and many brominated phenolic organics. Therefore, there is an urgent need toremove brominated organic pollutants produced in the process of producing flame retardants to reducethe harm to the environment and human beings and to reduce production costs. In this study, an efficientprocess was developed to treat the wastewater and waste residue generated in TBBPA production process,realizing its harmless and resource utilization. In the resource utilization system, through the ingeniousdesign of solution mixing, precipitation separation, three-effect evaporation and concentration,valuable substances were extracted to realize the recovery and reuse of wastewater. In the harmless utilizationprocess of hazardous waste residue, through high-temperature pyrolysis at 500 C for 2 h afteroptimization with hypoxia-hyperoxia atmosphere modulation, it can avoid the production of dioxinsand carbon black, effectively remove the organic impurities, realize the harmlessness and obtain highqualitysodium sulfate. This paper aims to propose a simple, efficient and feasible utilization system,including the three major technological processes of TBBPA production, integrated wastewater treatmentand optimized the harmless treatment of waste residue to obtain sodium sulfate, so as to realize TBBPAgreen production. Compared with the traditional TBBPA synthesis system, wastewater and waste residuetreatment processes, the TBBPA quality is increased by 2 % and the economic cost is reduced by 10 %,which is of great significance to the development of the industry.

Genome-wide identification of calcium-dependent protein kinases (CDPKs) in pear (Pyrus bretschneideri Rehd) and characterization of their responses to Venturia nashicola infection

Liu Shaohua,Li Junhao,Li Na,Zhou Peng,Li Liulin 한국원예학회 2022 Horticulture, Environment, and Biotechnology Vol.63 No.6

Calcium-dependent protein kinases (CDPKs) play signifi cant roles in response to environmental stresses in plants. However, the CDPK gene family in pear ( Pyrus bretschneideri Rehd) has not been thoroughly explored. In this study, we performed a comprehensive analysis of CDPK family genes in pear, and 30 CDPK genes were identifi ed, unevenly distributed across 13 chromosomes, and predicted to be mainly localized at the plasma membrane. Based on phylogenetic analysis and struc- tural features, the PbCDPKs were classifi ed into four distinct subfamilies. In addition, many putative cis-acting elements responsive to hormones and environmental stresses were identifi ed in the promoter regions. According to RNA-seq data, the majority of PbCDPK genes showed diff erential expression in diff erent pear tissues. After inoculation of plants with the fungus Venturia nashicola , four PbCDPK genes were diff erentially expressed in resistant and susceptible pear cultivars, suggesting that they might play an important role in resistance to the pear scab pathogen. These candidate genes will be subjected to disease resistance and functional analysis in future work. Our results thus provide a genome-wide characterization of CDPK family genes in pear and lay the foundation for further functional analysis.

Thin-film electronics based on all-2D van der Waals heterostructures

Liu Xinling,Yang Xiaomin,Sang Weihui,Huang Hai,Li Wenwu,Lin Yen-Fu,Chu Junhao 한국정보디스플레이학회 2021 Journal of information display Vol.22 No.4

Two-dimensional (2D) layered materials including metal, semiconductor, and insulator have received extensive attention in recent years. The weak van-der-Waals (vdW) interactions between 2D materials layers enable them to isolate monolayers and restack into artificial 2D vdW heterostructures in the desired sequence. These assembled all-2D vdW heterostructures are promising platforms for fabricating next-generation electronics as well as optoelectronics. In particular, the all-2D vdW heterostructure devices composed entirely of 2D layered material have received extensive attention due to their natural thickness, atomically sharp heterointerfaces, and excellent mechanical flexibility. Herein, we firstly introduce 2D vdW heterostructures and their preparation methods. Secondly, the recent progress of field-effect transistors (FETs) and photodetectors based on all-2D vdW heterostructures are summarized. Finally, we discuss some challenges of all-2D vdW heterostructure-based devices for practical applications and offer personal perspectives toward the future development of thin-film electronics.

Reliable Mobility Evaluation of Organic Field-Effect Transistors With Different Contact Metals

Huang, Fanming,Liu, Ao,Zhu, Huihui,Xu, Yong,Balestra, Francis,Ghibaudo, Gerard,Noh, Yong-Young,Chu, Junhao,Li, Wenwu IEEE 2019 IEEE electron device letters Vol.40 No.4

<P>The reliability of mobility evaluation of organic field-effect transistors (OFETs) is a serious issue because numerous overestimated and underestimated mobilities have been reported recently. A reliable approach to accurately evaluate the OFET mobility is therefore highly desirable. Here, in this letter, two commonly employed methods and the Y function method (YFM) were used to extract the mobilities of indacenodithiophene-co-benzothiadiazole (IDT-BT) OFETs with four different contact metals. The mobilities extracted by the commonly used methods varied greatly with the contact metal and channel length, whereas those extracted by the YFM were very stable and approached the intrinsic mobility of IDT-BT. Our results show that YFM is a precise approach that can be widely used to evaluate the OFET mobility.</P>

Modeling the Diffusion-Driven Growth of a Pre-Existing Gas Bubble

Anil Kunwar,Haitao Ma,Junhao Sun,Shuang Li,Jiahui Liu 대한금속·재료학회 2015 METALS AND MATERIALS International Vol.21 No.5

Finite element method is utilized to solve the diffusion equation and model the diffusion driven growth of a pre-existing spherical gas bubble in molten tin at the solder/substrate interface for reflow time of 120 s and temperature of 250 °C. The gibbs free energy change required for determining the equilibrium concentration at liquid solder/gas bubble boundary was calculated using the thermodynamic polynomial coefficients. The rate of change of radius, as function of concentration flux, is calculated using the lagrangian mesh update methodology. With an initial diameter of 20 μm, the bubble growth is calculated as a function of contact angle. When the wetting angle is varied from a value of 30° to 135°, the numerical calculation has yielded the final sizes for the bubble to change from 62.87 μm to 82.8 μm respectively. The effect of wetting transition in the growth of bubble was studied by the in-situ observation of bubble dynamics through synchrotron radiation imaging technique. The scanning electron microscopy images of the morphologies of intermetallic compounds influenced by growing bubble in Sn/Cu solder joint and bubble pictures obtained through synchrotron radiation are utilized to get the experimental size of the bubble. The mean experimental bubble diameter has been obtained as 76.39 μm. The growing bubble inhibits the growth of intermetallic compound at its vicinity and thereby reduces the strength of solder joints.

Catalytic graphene-mediated oxygen blocking and depletion for enhancing dual passive/active anticorrosion of epoxy coatings

Yan Tong,Cheng Meng,Liu Junhao,Sun Shuangqing,Hu Songqing 한국탄소학회 2022 Carbon Letters Vol.32 No.7

Doping graphene to epoxy resins can improve the protective ability of the coating, but the lack of active anticorrosion function greatly limits its application in the field of anticorrosion. Herein, N/S-rich few-layer-graphene (N/S-FLG) was prepared and adopted to endow epoxy coating with dual passive/active corrosion protection. The obtained amphiphilic N/S-FLG is highly dispersed in the epoxy coating, giving rise to the enhanced hosting effect for graphene defects, avoiding the interface corrosion and blocking the penetration of corrosive species. Furthermore, the doping of N and S endows graphene sheets favourable catalytic ability for corrosive oxygen, actively eliminating its contribution to metal corrosion. Under this dual effect, the passive and active anticorrosion properties of epoxy coating are simultaneously enhanced. The coating with 1 wt% N/S-FLG reduces the corrosion rate of metal to 6.5 × 10–5 mm/a, exhibiting almost no corrosion. The proposed concept of introducing nanocatalytic N/S-FLG is facile and eco-friendly, and will undoubtedly promote the practical application of anticorrosion coatings.