Effect of Surfactant Stabilizers on the Distribution of Carbon Nanotubes in Aqueous Media

The results of a study on the homogeneity of suspensions are described considering the effect of different types of surfactant stabilizers and their concentrations on the uniform distribution of a carbon nanotubes（CNTs）-based modifying additive to construction materials in an aqueous medium. This problem was solved herein by using surfactants and ultrasound. The sonication treatment of CNTs particle agglomerates allowed for dispersing their globules and achieving a 15-20-fold decrease in their average size, for which it became possible to make better use of the CNTs as cement modifier. As a result of the experimental studies carried out, the effect of the surfactant type and concentration promoting uniform distribution of the CNTs in the bulk of the suspension and, correspondingly, in the structural composite matrix was revealed. The CNTs-based additive improved the physical-mechanical and operational characteristics of the material.

Preparation of Magnetic Activated Carbon

Based on the special molccular structure of surfactant paramagnctic material used as magnetic nucleus wascoated with two layers of surfactant inculding an inner layer and an outer layer and an outer layer Magnetic reagent can combine with activated carbon due to adsorption of hydrophilic raclical of the outer surfactant layer so activated carbon has magnetism Theeffects of magnetic reagent dosage. pH and activator upon the magnetic susceptibility of activated carbon were studied.Conceming the optimal conditions. MR-20 is the best magnetic reagent. Concentration of CaCl2 is 0.02M and pH1.8-2.4The physical properties of magnetic activated carbon vary with the types dosage and magnetizing condition of magneticreagent.

Mesoporous carbon nanomaterials induced pulmonary surfactant inhibition,cytotoxicity,inflammation and lung fibrosis

Environmental exposure and health risk upon engineered nanomaterials are increasingly concerned. The family of mesoporous carbon nanomaterials（MCNs） is a rising star in nanotechnology for multidisciplinary research with versatile applications in electronics,energy and gas storage, and biomedicine. Meanwhile, there is mounting concern on their environmental health risks due to the growing production and usage of MCNs. The lung is the primary site for particle invasion under environmental exposure to nanomaterials. Here, we studied the comprehensive toxicological profile of MCNs in the lung under the scenario of moderate environmental exposure. It was found that at a low concentration of 10 μg/mL MCNs induced biophysical inhibition of natural pulmonary surfactant. Moreover, MCNs at similar concentrations reduced viability of J774 A.1 macrophages and lung epithelial A549 cells.Incubating with nature pulmonary surfactant effectively reduced the cytotoxicity of MCNs.Regarding the pro-inflammatory responses, MCNs activated macrophages in vitro, and stimulated lung inflammation in mice after inhalation exposure, associated with lung fibrosis.Moreover, we found that the size of MCNs played a significant role in regulating cytotoxicity and pro-inflammatory potential of this nanomaterial. In general, larger MCNs induced more pronounced cytotoxic and pro-inflammatory effects than their smaller counterparts. Our results provided valuable information on the toxicological profile and environmental health risks of MCNs, and suggested that fine-tuning the size of MCNs could be a practical precautionary design strategy to increase safety and biocompatibility of this nanomaterial.

Aqueous stability and mobility of C_(60) complexed by sodium dodecyl benzene sulfonate surfactant

Surfactant complexation may have significant effects on the environmental behavior of nano-particles.In order to understand the ecological exposure of nano-materials,it is important to determine the stability and mobility of surfactant-complexed nano-materials in aqueous systems.In this study,the aggregation and transport of C（60） complexed by the surfactant sodium dodecyl benzene sulfonate（SDBS）were investigated.It was found that SDBS-complexed C-（60） had aζ-potential of-49.5 m V under near-neutral p H conditions and remained stable during an aging period of 15 days.It had a critical coagulation concentration of 550 mmol/L for Na Cl,which was higher than common natural colloids and many kinds of raw nano-materials,and was comparable to those of many kinds of surface-modified nano-materials.SDBS enhanced the stability of C（60） colloid;however,at the same time,it also enhanced the colloidal particle aggregation rate.Much higher mobility was found for SDBS-complexed C（60） than C（60） colloid.Increase in ionic strength,Ca^2＋ concentration or Al^（3＋） concentration decreased the mobility.In general,SDBS-complexed C（60） had high stability and mobility.