INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Fenping Wang,Jiawei Li,Lin Lu,Xiaofei Yan,Ziwen Xie,Dongming Qi
Reversible addition–fragmentation chain transfer (RAFT) emulsion polymerization is a powerful tool for polymer encapsulation of pigment nanohybrids. Conventional RAFT emulsion polymers, however, contain sulfur residues that contribute to undesired odor and deleterious effects on final materials. Our strategy relies on an amphiphilic macromonomer poly(methacrylic acid-co-methyl methacrylate) P(MAA-co-MMA) with an ω-unsaturated end group synthesized in situ via cobalt(II)-mediated catalytic chain transfer polymerization (CCTP) at the surface of C.I. Pigment Blue 15:3 (PB) particles. Subsequently, these macromonomers are used as the living points to mediate the in situ sulfur-free RAFT (SF-RAFT) emulsion polymerization of monomers (butyl methacrylate (BMA) and butyl acrylate (BA)). It was found that a well-controlled polymerization process was achieved by semibatch SF-RAFT emulsion polymerization on the PB surface, as evidenced by the smooth increase in the molecular weight of polymer chains as the polymerization progressed and by transmission electron microscopy (TEM) results. Due to the sealing effect, these polymer/PB hybrid particles exhibited excellent colloidal stability in the aqueous phase. More importantly, film-forming hybrid particles with a soft P(BMA-co-BA) shell were successfully prepared in this work, which suggested that SF-RAFT-mediated polymerization may offer a useful alternative approach to traditional RAFT emulsion polymers for the preparation of organic/inorganic nanohybrids.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER RESEARCH
·
2025
·Vol. 32
·期 10
·1-10
·
IF 2.8
Du Chenglong,Huang Zhibo,Wu Xiaohui,Jing Shuailin,Wang Feifei,Liu Xiao,Shi Yan,Zhang Liqun
The increasing demand for brominated butyl rubber (BIIR) has intensified the use of conventional ZnO/sulfur-based curing systems, raising significant environmental concerns. Herein, we present a sustainable, ZnO- and sulfur-free cross-linking strategy enabled by a primary amine, octadecylamine (ODA), which serves as an efficient cross-linker for BIIR. Upon thermal activation at 160 °C, ODA reacts with the benzylic bromide groups of BIIR via dual nucleophilic substitution, forming stable covalent networks. The cross-link density and resultant mechanical properties exhibit a positive correlation with ODA loading, reaching an optimum at 3 phr. In contrast, octadecyltrimethylammonium bromide (OTAB) and diethylamine hydrochloride—lacking N–H protons—show negligible reactivity, highlighting the essential role of the primary amine functionality in the cross-linking mechanism. This work establishes a quantitative structure–efficiency relationship for amine-based cross-linkers, providing both experimental validation and mechanistic insight for the rational design of environmentally benign vulcanization processes in halogenated elastomers.
研究领域:
高分子化学
·
材料科学
·
环境友好材料
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橡胶工业
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可持续化学
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 24
·6014
·
IF 4.2
Rui Li,Yanhai Shao,Jinhui Li,Chenjie Liu,Hongqin Chen,Xiao Meng,Xinru Jia
The increasing demand for zinc resources and the declining availability of sulfide zinc ore reserves have made the efficient utilization of zinc oxide a topic of considerable interest. In this study, a ternary composite collector ABN (Al-BHA-NaOL system) was applied to the direct flotation of smithsonite. Micro-flotation studies showed that at pH 9, ABN exhibited better adsorption on smithsonite, achieving a recovery rate of 80.62%. Visual MINTEQ 3.1 and zeta potential analysis confirmed that ABN predominantly reacted with Zn(OH)2(aq) on the surface of smithsonite. Furthermore, X-ray photoelectron spectroscopy (XPS) analysis results elucidated the formation of Al-O bonds through chemical adsorption on the smithsonite surface. Additionally, powder contact angle measurements indicated that ABN enhances the surface contact angle of smithsonite. These results illuminate that ABN is adsorbed by reacting with O sites on hydroxylated metal ions on the smithsonite surface, with Al serving as the adsorption center, thereby achieving separation and purification. Due to ABN’s adsorption characteristics, smithsonite can achieve efficient and clean direct flotation recovery without sulfidization.
研究领域:
矿物加工工程
·
浮选化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL CROPS AND PRODUCTS
·
2025
·
IF 6.2
Bin Wang,Ze-Ming Hou,Ying-Jun Xu,Yu-Zhong Wang
Regenerated cellulose fibers are highly flammable, necessitating the application of flame retardants to reduce their fire hazard. In this study, a sulfur-free polymeric flame retardant (PPSPB) was employed to enhance the flame retardancy of viscose fibers (VF), while addressing the smoke release concern associated with commercial organophosphorus flame retardants. PPSPB stayed stability against hydrolysis and agglomeration in water, thereby meeting the strict requirement of viscose spinning. PPSPB presented good compatibility with VF and a low migration tendency from VF, enabling VF to maintain high whiteness, superior moisture absorption, good mechanical properties, and exceptional washing fastness. VF/PPSPB 20 , containing 20 wt% PPSPB, achieved a limiting oxygen value of 29.5 % and presented a sharp reduction in the heat release with a moderate smoke release in cone calorimetry tests. PPSPB showed dominant condensed-phase flame-retardant mechanisms via promoting cellulose dehydration and enhancing char formation. It also presented vapor-phase flame-retardant activities through facilitating the generation of nonflammable gaseous products. This work opens a feasible approach for producing flame-retardant regenerated cellulose fibers using polymeric flame retardants.
研究领域:
材料科学
·
阻燃技术
✓ 已验证
产品关联
DOI
高影响因子
Scientific Reports
·
2016
·Vol. 6
·期 1
·1-7
·
IF 5.228
Yu Chao,Wang Cai-Feng,Chen Su
Methods allowing the oxidation of graphite to graphene oxide (GO) are vital important for the production of graphene from GO. This oxidation reaction has mainly relied on strong acid strategy for 174 years, which circumvents issues associated with toxicity of reagent and product, complex post-treatment, high cost and waste generation. Here, we report a green route for performing this oxidization reaction via a ferro-induced strategy, with use of water, potassium ferrate (Fe(VI)) and hydrogen peroxide (H 2 O 2 ) as reagents, to produce about 65% yield of GO (vs. 40% for Hummers’ method, the most commonly used concentrated acid strategy) and non-toxic by-products. Moreover, GO produced from this new method shows equivalent performance to those reported previously. This H 2 SO 4 -free strategy makes it possible to process graphite into GO in a safe, low-cost, time-saving, energy-efficient and eco-friendly pathway, opening a promising avenue for the large-scale production of GO and GO-based materials.
研究领域:
材料科学
·
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMISTRY OF MATERIALS
·
2023
·
IF 8.6
Jieyu Zhang,Jingjing Min,Binghan Li,Wenxing Yang,Zaiping Zeng,Dianyi Liu,Botao Ji
Environmentally friendly Ag2S nanocrystals (NCs) show potential applications as light-absorbing semiconductors for thin-film photovoltaics or biological taggants. However, thiol ligands are generally involved during the synthesis of Ag2S NCs to maintain colloidal stability, hindering postexchange of these crystal-bound thiolate ligands. Here, using common non-thiol ligands (oleic acid and oleylamine), we develop a general strategy of surface heterovalent-metal (Bi3+, Ga3+, In3+, Sb3+, and Zn2+) decoration to synthesize colloidal cation-rich Ag2S NCs achieving a high photoluminescence quantum yield up to 22% at ∼1230 nm. Density functional theory calculations reveal the heterovalent-metal cations exhibit stronger orbital coupling to the ligands than Ag atoms, and thus stronger binding affinity, resulting in reduced dynamic surface ligands to produce compact cation-rich Ag2S NCs with high solubility in nonpolar solvents. We further show that surface-decorated Bi atoms can accumulate the electron charge density, leading to surface-related band-edge emissions with increased electron–hole separation and prolonged exciton lifetimes of the Bi-decorated Ag2S NCs, which are desirable for many optoelectronic conversion applications. Using a 40 nm-thick light-absorbing layer of Bi-decorated Ag2S NCs, the optimized solar cells show a short-circuit current density of 18.6 mA cm–2 and a power conversion efficiency of over 4%.
研究领域:
材料科学
·
纳米技术
·
光伏技术
·
光电技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）