Tribochemistry of alcohols and their tribological properties: a review

Recently,alcohols have attracted more attention due to their excellent tribological performance,especially superlubricity under low loads.Alcohol solution,as a liquid lubricant,can easily reach the superlubricity state under low loads because of the formed low shear hydroxylation interfaces induced by the tribochemical reactions.A general picture and its influencing factors have been elucidated,not only at the macroscopic scale but also at the nanoscale,which is sufficient to provide effective guidance for lubrication design and tribology research in engineering.Herein,we provide a review on the recent applications of alcohols in lubrication.In addition,the material transformation caused by alcohols in friction is a key factor affecting the tribological properties.As an important two-dimensional material,the growth mechanisms of graphene are variable,and the most famous is the formation of carbon radicals under the action of metal catalysts.Thus,based on the formation mechanism of carbon friction film(such as amorphous carbon and graphene),the main content of this review also includes the transformation of graphene in alcohol solution friction process.

Zero-valent iron doped carbons readily developed from sewage sludge for lead removal from aqueous solution

Low-cost but high-efficiency composites of iron-containing porous carbons were prepared using sewage sludge and ferric salts as raw materials. Unlike previous time- and energy-consuming manufacturing procedures, this study shows that pyrolyzing a mixture of sludge and ferric salt can produce suitable composites for lead adsorption. The specific surface area, the total pore volume and the average pore width of the optimal composite were 321 m^2/g, 0.25 cm^3/g, and 3.17 nm, respectively. X-ray diffraction analysis indicated that ferric salt favored the formation of metallic iron, while Fourier transform infrared spectroscopy revealed the formation of hydroxyl and carboxylic groups. The result of batch tests indicated that the adsorption capacity of carbons activated with ferric salt could be as high as 128.9 mg/g, while that of carbons without activation was 79.1 mg/g. The new manufacturing procedure used in this study could save at least 19.5 k J of energy per gram of activated carbon.

Biased heteroplasmy within the mitogenomic sequences of Gigantometra gigas revealed by sanger and high-throughput methods

Few studies have explored the differences between Sanger and HTS methods in the results of mitogenome sequencing. We used a single individual of insect to study the differences between the sequences given by Sanger and PCR-free HTS methods. Here we provided evidence for biased results of sequencing due to different methods in the mitochondrial genes of atp6, atp8, cox1, cox2, cox3, Cytb, nad2, nad3, nad4, nad5, rrn S, rrnL, trnH, trn I, and control region at various degrees. Especially, in cox1, the differently sequenced nucleotides account for 2.6% of the complete length. Furthermore, the highest value of the intraspecific genetic distance based on K2 P accounts for 2.5% using a barcode fragment size of cox1（651 bp, Sanger）, while the maximum distance of the corresponding cox1 fragment obtained by the two sequencing methods was 5.0%. We revealed that the methods of Sanger and HTS may give different sequencing results of mitochondrial genes, which may reflect the heteroplasmy of mitogenomes within an insect individual. Therefore, researchers should be very cautious in using the mixed data of a gene given by different methods of sequencing.