Multifunctional Antibacterial and Hydrophobic Cotton Fabrics Treated with Cyclic Polysiloxane Quaternary Ammonium Salt

Jian Liu,Chaohong Dong,Dongdong Wei,Zheng Zhang,Weihao Xie,Qun Li,Zhou Lu 한국섬유공학회 2019 Fibers and polymers Vol.20 No.7

A novel polysiloxane quaternary ammonium salt (NCTSi) was synthesized and used as antibacterial andhydrophobic agent for cotton fabric. The chemical structures were characterized by FT-IR. The surface morphology of treatedcotton fabrics was characterized by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). Thecotton fabrics treated with NCTSi showed excellent antibacterial properties against Gram-positive bacteria S. aureus andGram-negative bacteria E. coli. The E. coli antibacterial rate was about 99.52 % and the S. aureus antibacterial rate was about98.33 %, with only a slight decrease after 20 cycles of standard washing, to 91.43 % and 93.33 %, respectively. The inhibitionzone was 2 mm and 2.5 mm against E. coli and S. aureus when NCTSi concentration was 4 %. The treated cotton fabricsprovided excellent hydrophobic properties, and the water contact angle (WCA) reached 124.14 º compared to pure cottonfabrics. The mechanical properties and whiteness were also investigated. As a result of the performed modifications,multifunctional fabrics with a considerably increased hydrophobicity and high antibacterial property were obtained.

A Novel Cyclic Polysiloxane Linked by Guanidyl Groups Used as Flame Retardant and Antimicrobial Agent on Cotton Fabrics

Dongdong Wei,Chaohong Dong,Jian Liu,Zheng Zhang,Zhou Lu 한국섬유공학회 2019 Fibers and polymers Vol.20 No.7

A novel flame retardant and antibacterial agent, (tetramethylcyclosiloxyl-piperazin) tetra guanidine (GNCTSi)used for cotton fabrics was successfully synthesized. The limiting oxygen index (LOI) value of cotton fabric treated with250 g/l GNCTSi reached to 30.1 %. The vertical burning test results showed that the char length of the treated cotton fabricwas 6.5 cm and have no after-flame and no after-glow. Compared with untreated cotton fabric, the treated cotton fabricshowed better flame retardancy and higher residue rate by themogravimetric analysis (TG). The GNCTSi exists on the treatedcotton fabric was observed and the residues of cotton fabric after combustion had a homogeneous surface without break byscanning electron microscopy (SEM). The treated cotton fabric showed good antibacterial activity against E. coli and S. aureus and the inhibition zone were 2.5 mm and 2.3 mm, respectively. After repeated washing, the LOI of cotton fabric is stillhigher than 26 %.

Multifunctional, Hydrophobic and Flame-retarded Cotton Fabrics Modified with Liner Piperzine/Phosphorous/Polysiloxane Copolymer

Zhaohua Chen,Chaohong Dong,Qun Li,Yue Pu,Zhou Lu 한국섬유공학회 2018 Fibers and polymers Vol.19 No.4

α,ω-di[(4-butoxy-piperazin-1-yl)-phosphinic acid methyl ether]-terminated linear polysiloxane (PNPDMS) was synthesized and utilized as the flame retardant and hydrophobing agent. The flame retardance and thermal decomposition behaviors of cotton fabrics were systematically estimated by limiting oxygen index (LOI), thermogravimetric analysis and vertical burning test, respectively. It was found that the LOI of cotton fabric treated with PNPDMS enhanced to 29.82 % compared with cotton fabric without treatment, whose LOI was only 18.00 %. The treated cotton fabric showed a shorter char length, a shorter After-flame time, and no After-glow time as revealed in vertical burning test. The mechanical property in treated cotton fabric was slightly decrease. Furthermore, the grade of water repellency of treated cotton fabric reached to 90 and water contact angle (WCA) increased to 141.90 o compared with cotton fabric without treatment whose WCA was 62.80 o. The result showed that the cotton fabric treated with PNPDMS exhibited excellent flame retardance and hydrophobic properties.

Synthesis of a Novel N-halamine-based Cyclic Polysiloxane and Its Antibacterial Application on Cotton Fabrics

Jian Liu,Chaohong Dong,Zheng Zhang,Dongdong Wei,Zhou Lu 한국섬유공학회 2020 Fibers and polymers Vol.21 No.2

A novel N-halamine-based cyclic polysiloxane compound (KCNCTSi) was synthesized and used as an antibacterial agent on cotton fabric. The structures were characterized by Fourier transform infrared spectra (FTIR). The surface morphology of treated cotton fabrics was tested by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS). The treated cotton fabrics were tested by thermogravimetric analysis (TGA) and showed good thermal stability. The treated cotton fabrics after chlorination exhibited strong antibacterial efficiency against Gram-positive bacteria S. aureus and Gram-negative bacteria E. coli. The E. coli antibacterial rate was about 98.35 % and the S. aureus antibacterial rate was about 99.51 %. The inhibition zones were 1 mm and 1.5 mm against E. coli and S. aureus when KCNCTSi concentration was 350 g/l. The mechanical properties and whiteness were also investigated. As a result of the performed modifications, cotton fabrics with high antibacterial property were obtained.

Formosanin C attenuates lipopolysaccharide-induced inflammation through nuclear factor-κB inhibition in macrophages

Limin Yin,Chaohong Shi,Zhongchen Zhang,Wensheng Wang,Ming Li 대한생리학회-대한약리학회 2021 The Korean Journal of Physiology & Pharmacology Vol.25 No.5

Extended inflammation and cytokine production pathogenically contribute to a number of inflammatory disorders. Formosanin C (FC) is the major diosgenin saponin found in herb Paris formosana Hayata (Liliaceae), which has been shown to exert anti-cancer and immunomodulatory functions. In this study, we aimed to investigate anti-inflammatory activity of FC and the underlying molecular mechanism. RAW264.7 macrophages were stimulated with lipopolysaccharide (LPS) or pretreated with FC prior to being stimulated with LPS. Thereafter, the macrophages were subjected to analysis of the expression levels of pro-inflammatory mediators, including nitric oxide (NO), prostaglandin E2 (PGE), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-6, as well as two relevant enzymes, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). The analysis revealed that FC administration blunted LPS-induced production of NO and PGE in a dose-dependent manner, while the expression of iNOS and COX-2 at both mRNA and protein levels was inhibited in LPS-stimulated macrophages pre-treated with FC. Moreover, LPS stimulation upregulated mRNA expression and medium release of TNF-α, IL-1β, and IL- 6, whereas this effect was blocked upon FC pre-administration. Mechanistic studies showed that inhibitory effects of FC on LPS-induced inflammation were associated with a downregulation of IκB kinase, IκB, and p65/NF-κB pathway. Taken together, these data suggest that FC possesses an inflammation-suppressing activity, thus being a potential agent for the treatment of inflammation-associated disorders.

Experimental study on U-shape flat thermosyphon for thermal management of power battery

Tao Wang,Sicong Tan,Cong Guo,Hongchao Su,Chaohong Guo,Yuyan Jiang 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.9

The paper presents a new type of U-shape flat thermosyphon. The thermosyphon has several unique properties relative to general heat pipe such as compact and simple structure (no wick structure), easily to filling the coolant and flexible plate structure and so on. These properties make it an ideal heat transfer device for battery pack thermal management. In this paper, we experimentally study the thermal management performance of the U-shape flat thermosyphon for a battery module. The temperature of the battery module can be controlled below 50 °C under 1.5 C charge rate (300 W), and below 37 °C under 1 C charge rate (120 W), and the corresponding maximum temperature difference is 3 °C and 7 °C, respectively. And higher power generation is helpful to start-up the U-shape flat thermosyphonand maintain a small temperature difference between different battery cells. The performance of the U-shape flat thermosyphonis evaluated using a thermal resistance network model, which showed that there is uneven distribution of heat transfer in the two side of the heat pipe.