scholarly journals Black phosphorus quantum dots: A new-type of water-based high-efficiency lubricant additive

Friction ◽  
2020 ◽  
Author(s):  
Weiwei Tang ◽  
Zhiqiang Jiang ◽  
Baogang Wang ◽  
Yufeng Li

AbstractBlack phosphorus quantum dots (BPQDs), obtained via a typical solution-based top-down method, were used as water-based lubricant additives. BPQDs exhibited remarkable friction reduction and anti-wear properties even at the ultra-low concentration of 0.005 wt%, which reduced the friction coefficient and wear volume of the base liquid by 32.3% and 56.4%, respectively. In addition, the load-supporting capacity of the base liquid increased from 120 N to over 300 N. BPQDs-based additives exhibited a relatively long lifetime at a relatively high load of 80 N. The performance of BPQDs considerably exceeded that of the BP; this may be attributed to their small and uniform particle size, good dispersion stability in water, and high reactivity at the frictional surfaces. The results of the surface wear resistance analysis demonstrated that a robust tribochemical film with a thickness of approximately 90 nm was formed on the rubbing surface lubricated with 0.005 wt% of BPQDs dispersion. Moreover, the film served as a direct evidence of the excellent tribological performance of BPQDs.

2018 ◽  
Vol 6 (19) ◽  
pp. 8886-8894 ◽  
Author(s):  
Nianqing Fu ◽  
Chun Huang ◽  
Peng Lin ◽  
Mingshan Zhu ◽  
Tao Li ◽  
...  

Dual-functional black phosphorus quantum dot electron selective layer was designed for plastic perovskite solar cells. The efficient electron extraction and improved perovskite film quality contributed to the reasonably high efficiency.


2021 ◽  
pp. 132163
Author(s):  
Xiaoyu Fan ◽  
Shuai Zhang ◽  
Rentian Guan ◽  
Xiaodong Shao ◽  
Shuhan Jiang ◽  
...  

NANO ◽  
2017 ◽  
Vol 12 (09) ◽  
pp. 1750108 ◽  
Author(s):  
Xiang Liu ◽  
Zhiyu Huang ◽  
Weiwei Tang ◽  
Baogang Wang

Ionic liquid modified carbon dots (CDs-IL) were successfully synthesized by one-pot pyrolysis. The tribological properties of CDs-IL as a kind of water-based lubricant additive were investigated under four-ball mode. The experimental results demonstrated that the added CDs-IL not only increased load-carrying capacity of base liquid but also displayed remarkable friction-reducing and antiwear properties. At an optimal concentration of 0.05[Formula: see text]wt.% and a proper load of 50[Formula: see text]N, the mean friction coefficient and wear volume reduced by 65% and 60%, respectively. The remarkable lubricating effect of CDs-IL was attributed to the boundary tribofilm formed by absorption and deposition of CDs-IL on rubbing surfaces. The lubricating effect of CDs-IL especially antiwear effect greatly attenuated when the load was lower or higher than 50 N because the function of deposition tribofilm formed by CDs-IL was suppressed by the absorption tribofilm or tribochemical film derived from triethanolamine in base liquid, respectively.


ACS Nano ◽  
2018 ◽  
Vol 12 (12) ◽  
pp. 12401-12415 ◽  
Author(s):  
Leung Chan ◽  
Pan Gao ◽  
Wenhua Zhou ◽  
Chaoming Mei ◽  
Yanyu Huang ◽  
...  

2021 ◽  
Vol 290 ◽  
pp. 129477
Author(s):  
Naveen Bokka ◽  
Vivek Adepu ◽  
Venkatarao Selamneni ◽  
Parikshit Sahatiya

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Shibo Xu ◽  
Linna Chang ◽  
Yanan Hu ◽  
Xingjun Zhao ◽  
Shuocheng Huang ◽  
...  

Abstract Background Healing of MRSA (methicillin-resistant Staphylococcus aureus) infected deep burn wounds (MIDBW) in diabetic patients remains an obstacle but is a cutting-edge research problem in clinical science. Surgical debridement and continuous antibiotic use remain the primary clinical treatment for MIDBW. However, suboptimal pharmacokinetics and high doses of antibiotics often cause serious side effects such as fatal complications of drug-resistant bacterial infections. MRSA, which causes wound infection, is currently a bacterium of concern in diabetic wound healing. In more severe cases, it can even lead to amputation of the patient's limb. The development of bioactive nanomaterials that can promote infected wound healing is significant. Results The present work proposed a strategy of using EGCG (Epigallocatechin gallate) modified black phosphorus quantum dots (BPQDs) as therapeutic nanoplatforms for MIDBW to achieve the synergistic functions of NIR (near-infrared)-response, ROS-generation, sterilization, and promoting wound healing. The electron spin resonance results revealed that EGCG-BPQDs@H had a more vital photocatalytic ability to produce singlet oxygen than BPQDs@H. The inhibition results indicated an effective bactericidal rate of 88.6% against MRSA. Molecular biology analysis demonstrated that EGCG-BPQDs significantly upregulated CD31 nearly fourfold and basic fibroblast growth factor (bFGF) nearly twofold, which were beneficial for promoting the proliferation of vascular endothelial cells and skin epidermal cells. Under NIR irradiation, EGCG-BPQDs hydrogel (EGCG-BPQDs@H) treated MIDBW area could rapidly raise temperature up to 55 °C for sterilization. The MIBDW closure rate of rats after 21 days of treatment was 92.4%, much better than that of 61.1% of the control group. The engineered EGCG-BPQDs@H were found to promote MIDBW healing by triggering the PI3K/AKT and ERK1/2 signaling pathways, which could enhance cell proliferation and differentiation. In addition, intravenous circulation experiment showed good biocompatibility of EGCG-BPQDs@H. No significant damage to major organs was observed in rats. Conclusions The obtained results demonstrated that EGCG-BPQDs@H achieved the synergistic functions of photocatalytic property, photothermal effects and promoted wound healing, and are promising multifunctional nanoplatforms for MIDBW healing in diabetics. Graphical Abstract


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