CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xiaodong Jin,Xinyi Wu,Wufei Tang,Zheni Tan,Wanfu Wang,Shibing Sun
Layer by layer (LBL) self-assembly coatings upon expandable polystyrene (EPS) surface play an important role in improving its flame retardancy. However, a large number of layers is needed to achieve a satisfied fire performance, and the coatings are difficult to adhere on the inert EPS surface, resulting in the poor durability. In this work, the surface of EPS was activated by ultraviolet ozone (UVO) with the appearance of oxygen contained groups, then a LBL coating with only two bilayers (branched polyethyleneimine (BPEI)-kaolinite (kaol)-BPEI-diethylene triamine penta (methylene phosphonic acid)) was covalently connected on the EPS surface. Compared with neat EPS, the obtained E-K 5 D 30 sample increased the value of limiting oxygen index (LOI) from 18.8 % to 37.7 %, improved the ignition time from 59 s to 95 s, reduced the peak heat release rate (pHRR) value from 282.0 kW/m 2 to 220.9 kW/m 2 , and enhanced the char residues from 6.3 % to 32.3 % after the combustion. Moreover, an ultraviolet (UV) curing layer with P/N elements was prepared upon E-K 5 D 30 sample to maximize the flame retardant durability. A novel amino-intercalated kaol was used to play a smoke suppression role. The results showed that E-K* 5 D 30 -P 8 N 3 sample further increased the LOI to 39.2 %. Even after 12 h washing, the E-K* 5 D 30 -P 8 N 3 sample exhibited a slight LOI reduction to 37.8 %, and fire performance index (FPI) value of 0.405 m 2 ·s/kW, showing the successful construction of coatings with good fire safety and flame retardant durability.
研究领域:
材料科学
·
聚合物化学
·
消防安全工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Ke Deng,Ping Du,Kun Liu,Xuelian Tao,Javad Harati,Jhe-Wei Jhang,Jua Kim,Peng-Yuan Wang
Hybrid surfaces with tunable topography, chemistry, and stiffness have potential to rebuild native extracellular matrix (ECM) and manipulate cell behavior in vitro. However, the fabrication of controllable hybrid surfaces is still challenging. In this study, colloidal self-assembly technology was used to program particles into highly ordered structures with hybrid chemistry and stiffness at biointerfaces. These colloidal self-assembled patterns (cSAPs), including unary, binary, and ternary cSAPs, composed of silicon (Si), polystyrene (PS), and/or poly(N-isopropylacrylamide) (pNIPAM) nanogels (PNGs), were fabricated using either coassembly or layer-by-layer (LBL) methods. The selected binary cSAPs (i.e., PS/PNG and PNG/PS) have a tunable surface topography and wettability between 25 and 37 °C; thus, they can be used as dynamic cell culture substrates. Human adipose-derived mesenchymal stem cells (hASCs), bone marrow-derived mesenchymal stem cells (hBMSCs), and macrophages (THP-1) were investigated on these hybrid cSAPs under a static or dynamic system. The results showed that hybrid cSAPs significantly influenced the focal adhesions, cell morphology, cell migration, and gene expressions of stem cells. In general, stem cells had more vinculin puncta, smaller spreading size, and faster migration speed than the TCPS control. Hybrid cSAPs up-regulated gene expressions of focal adhesion kinase (FAK) and chondrocytes (AGG and SOX9) under static culture, while they also up-regulated osteocytes (COL1 and RUNX2) under dynamic culture. THP-1 macrophages were at M0 state on all cSAPs under static culture. However, cells became sensitive under dynamic culture. For example, some M1 genes (i.e., IL6, CD68, and TNFα) and M2 genes (i.e., IL10 and CD206) were down-regulated, while other M1 genes (i.e., IL1β) and M2 genes (i.e., TGF-β and IL1ra) were up-regulated, depending on the particle combinations. In conclusion, new hybrid cSAPs with thermoresponsive surface properties are versatile materials for stem cells and macrophages manipulation.
研究领域:
材料科学
·
生物医学工程
·
细胞生物学
·
组织工程
·
再生医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）