scholarly journals Inorganic and Organic Hybrid Nanoparticles as Multifunctional Crosslinkers for Rubber Vulcanization with High-Filler Rubber Interaction

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1138 ◽  
Author(s):  
Lijuan Chen ◽  
Xiaohui Guo ◽  
Yuanfang Luo ◽  
Zhixin Jia ◽  
Yongjun Chen ◽  
...  

Improving the interfacial interaction between rubber and silica nanoparticles, and simultaneously reducing free sulfur and preventing migration and volatilization of a rubber vulcanizing agent, commercial sulfur compound aliphatic ether polysulfide (VA-7) was chemically attached to the silica surface to obtain a functionalized nanoparticle (silica-s-VA7). Functional nanoparticles can not only effectively crosslink rubber without sulfur as a novel vulcanizator, but are also evenly dispersed in the rubber matrix and improve the dispersion of the remaining pristine silica as an interfacial compatibilizer. In addition, the thicker immobilized polymer layer and prominent crosslinking density of SBR nanocomposites simultaneously demonstrate that the novel vulcanizing agent silica-s-VA7 gives rise to significant improvement on the rubber–filler interfacial adhesion on account of the covalent linkages of organic and inorganic interfaces between elastomer and nanofillers. We envisage that this strategy may provide a new avenue to implement high-efficiency design for a multifunctional rubber-vulcanizing agent through an organic and inorganic hybridization mechanism.

2021 ◽  
Vol 22 (13) ◽  
pp. 6850
Author(s):  
Seyyed Mojtaba Mousavi ◽  
Seyyed Alireza Hashemi ◽  
Sonia Bahrani ◽  
Khadije Yousefi ◽  
Gity Behbudi ◽  
...  

In this review, the unique properties of intrinsically conducting polymer (ICP) in biomedical engineering fields are summarized. Polythiophene and its valuable derivatives are known as potent materials that can broadly be applied in biosensors, DNA, and gene delivery applications. Moreover, this material plays a basic role in curing and promoting anti-HIV drugs. Some of the thiophene’s derivatives were chosen for different experiments and investigations to study their behavior and effects while binding with different materials and establishing new compounds. Many methods were considered for electrode coating and the conversion of thiophene to different monomers to improve their functions and to use them for a new generation of novel medical usages. It is believed that polythiophenes and their derivatives can be used in the future as a substitute for many old-fashioned ways of creating chemical biosensors polymeric materials and also drugs with lower side effects yet having a more effective response. It can be noted that syncing biochemistry with biomedical engineering will lead to a new generation of science, especially one that involves high-efficiency polymers. Therefore, since polythiophene can be customized with many derivatives, some of the novel combinations are covered in this review.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1859
Author(s):  
Yunys Pérez-Betancourt ◽  
Péricles Marques Araujo ◽  
Bianca de Carvalho Lins Fernandes Távora ◽  
Daniele Rodrigues Pereira ◽  
Eliana Lima Faquim-Mauro ◽  
...  

Nanostructures have been of paramount importance for developing immunoadjuvants. They must be cationic and non-cytotoxic, easily assembling with usually oppositely charged antigens such as proteins, haptens or nucleic acids for use in vaccines. We obtained optimal hybrid nanoparticles (NPs) from the biocompatible polymer poly(methyl methacrylate) (PMMA) and the cationic lipid dioctadecyl dimethyl ammonium bromide (DODAB) by emulsion polymerization of methyl methacrylate (MMA) in the presence of DODAB. NPs adsorbed ovalbumin (OVA) as a model antigen and we determined their adjuvant properties. Interestingly, they elicited high double immune responses of the cellular and humoral types overcoming the poor biocompatibility of DODAB-based adjuvants of the bilayer type. The results suggested that the novel adjuvant would be possibly of use in a variety of vaccines.


ACTA IMEKO ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 125
Author(s):  
Zsolt János Viharos ◽  
László Móricz ◽  
Máté István Büki

The 21st century manufacturing technology is unimagined without the various CAM (Computer Aided Manufacturing) toolpath generation programs. The aims of developing the toolpath strategies which are offered by the cutting control software is to ensure the longest possible tool lifetime and high efficiency of the cutting method. In this paper, the goal is to compare the efficiency of the 3 types of tool path strategies in the very special field of micro-milling of ceramic materials. The dimensional distortion of the manufactured geometries served to draw the Taylor curve for describing the wearing progress of the cutting tool helping to determine the worn-in, normal and wear out stages. These isolations allow to separate the connected high-frequency vibration measurements as well. Applying the novel feature selection technique of the authors, the basis for the vibration based micro-milling tool condition monitoring for ceramics cutting is presented for different toolpath strategies. It resulted in the identification of the most relevant vibration signal features and the presentation of the identified and automatically separated tool wearing stages as well.


2021 ◽  
Author(s):  
Zhishuncheng Li ◽  
GuangFei Qu ◽  
Yanhua He ◽  
Ping Ning ◽  
Ruosong Xie ◽  
...  

Abstract In this paper, we studied the catalytic pyrolysis behavior of microcrystalline cellulose (MC) in catalytic systems with acidic [Bmim]OTf as the media at temperatures of 140°C, 180°C, 220°C, 260°C, and 300°C. The pyrolysis behavior was investigated via SEM, XRD, FTIR, and GC-MS. During the catalysis of [Bmim]OTf, the pyrolysis temperature of MC was reduced to 140°C significantly and the crystalline structure of MC was destroyed rapidly. The novel synergistic catalytic effect of CF3SO3- and [Bmim]+ was discovered, which may lead to MC-selective cleavage of glycosidic, C-C, C-O, and C-H bonds, accompanied by new bond formation, which showed the production of many small molecular compounds. Furthermore, a novel mechanism model of evolution in [Bmim]OTf at low temperature was developed from a microscopic point of view. This research had obvious significance for the mechanism of directional regulation of target products, finally realizing the high efficiency utilization of biomass.


Minerals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 2 ◽  
Author(s):  
Qian Peng ◽  
Xuekun Tang ◽  
Kun Liu ◽  
Xianping Luo ◽  
Dongsheng He ◽  
...  

In the study, magnesium oxide (MgO) was used to catalyze peroxymonosulfate (PMS) for the degradation of organic pollutants for the first time. According to the single-factor experiment results, it was determined that MgO could efficiently catalyze PMS to degrade organic matters in a wide range of pH values. Based on radical quenching experiments and electron spinning resonance spectra, singlet oxygen was identified to be the crucial reactive species. Importantly, the oxygen vacancy on the surface of MgO was determined as the key active site, which accelerated the decomposition of PMS to produce singlet oxygen. This study provides an interesting insight into the novel and ignored catalyst of MgO for the highly efficient activation of PMS, which will greatly benefit the Fenton-like catalytic degradation of organic wastewater.


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