Ball-milling method

D 408 - 37 T. Tentative method of test for grindability of coal by the ball-mill method. Part III, pp. 562-565. 

Traditionally, selenides have been synthesized at high temperature (>500 °C) by solid-state reaction [131] or self-propagating synthesis [132]. A high-energy ball milling method at room temperature has also been used [133], however, the product quality was difficult to control. In liquid ammonia, a low-temperature route to selenides was developed [134]. Organometallic precursors have been used to obtain... 

There are advantages and disadvantages in both processes the solvent process requires no special equipment but uses an excess of benzene whose recovery adds to the cost of the product. The ball mill method uses no excess benzene but requires special equipment which has frequent mechanical problems. 

Synthesis sequence of ball-milling method for SnOj-based device materials. Dl, deionized. 

Leady oxide manufacture. Pure lead ingots are subjected to simultaneous grinding and surface oxidation (ball-mill method) or are melted and oxidized in humidified air (Barton pot method). A 60—80% oxidized lead powder (leady oxide) is obtained with a corresponding particle size distribution. 

The ball mill method was first invented by Shimadzu in Japan in 1924. Nowadays, a great variety of mill designs are in use, but the basic principles applied by Shimadzu remains the same. The ball mill process is based on sobd-phase reactions and operates within the temperature range between 70 and 180 °C. Schematic of a conical ball mill system is presented in Fig. 5.6 [15]. 

Leady oxide consists of lead oxide and free metallic lead. When produced by the ball mill method, the degree of oxidation of 65—75% is achieved, while the Barton process yields leady oxide powder with 70—80 wt% PbO content. When the leady oxide contains more than 30 wt% free lead, the material becomes very reactive. It is readily oxidized in humid air and the heat produced by this exothermic reaction may lead to combustion and damage the production equipment. Hence, effective control of the percent content of imoxidized lead in the leady oxide is very important, both during the production process and during the subsequent handling and storage of the leady oxide. 

The acid absorption of the leady oxide is determined by a method similar to that applied for determining the water absorption, but in this case sulfuric acid with 1.10 relative density is used instead of water. Depending on the method of leady oxide production and on the equipment used, the acid absorption value varies. Figure 5.10 presents the acid absorption (in mg H2SO4 per g oxide) as a function of the BET surface area for leady oxides produced by the Barton pot and ball mill methods [21]. 

Figure 5.11 presents the particle size distribution curve for leady oxide produced by the ball mill method. The determination was performed by sedimentation analysis of the leady oxide in 0.1% NaPOs solution at 36 °C. The obtained data evidence that all leady oxide particles are... 

By replacement of Binam-L-proline 114 used in work described above with pro-linethioamide catalyst 117, Mjera obtained better results (Scheme 2.40) [32]. When prolinethioamide catalyst was employed in conjunction with p-nitrobenzoic acid as a cocatalyst, reactions were finished in very short time (Table 2.34). The efficacy of catalyst was not improved when the reaction was performed in a ball mill (method C)... 

Schniirch and Stanetty have shown that synthesis of boionic add esters could be effectively carried out in ball mill (Scheme 4.49) [37]. Equimolar quantities of pinacol or 2,2-dimethylpropan-l,3-diol milled with boronic adds for Ih and washed up with organic solvent afford boronic esters 174 and 175 in excellent purity and high yields (Table 4.17). This ball-milling method is atom efficient and waste free, requiring only a small amounts of nontoxic solvents (ether, ethanol) for isolation. Reaction is much faster (1 h) than the classical methods (several hours or days) which also need removal of water by azeotropic distillation. The scale-up by factor 20 was performed on a Fritsch Analysette 3 PRO ball mill, with the same efficiency as in small-scale batches. 

Spex 8000M mixer mill, stainless steel vial and ball (5mm), 18Hz, stainless steel ball (5mm). Reproduced from Shearouse WC, Korte CM, Mack J. A two-step ball milling method synthesizes and purifies a,p-unsaturated esters. Green Chem 2011 13.598-601, with permission from the Royal Socsty of Chemistry. 

Shearouse WC, Korte CM, Mack J. A two-step ball milling method synthesizes and purifies a,p-unsaturated esters. Green Chem 2011 13 598-601. 

Ball-milling method was also employed by other researchers for functionalization of SWNTs functional groups such as thiol, amine, amide, carbonyl, and chlorine were introduced by milling in reactive atmospheres by Konya [35], alkyl halides were used by Barthos [36], whereas Qin employed KOH to prepare SWNTubols [37] and Ceo to obtain Cso-modified SWNTs [38],... 

Sulfur/polypyrrole binary composite was prepared by a simple one-step ball milling method as cathode for LIB, and it was demonstrated that by making the composite with polypyrrole, the dissolution of polysulfide in the electrolyte is reduced [39]. The result of Li/S battery with S/PPy showed high initial discharge capacity of 1320 mAh/g and a stable reversible capacity of 500 mAh/g after 40 cycles. 

Wu et al. reported that a new kind of NR/organo-vermiculite (OVMT) nanocomposite was prepared via a melt process in a HAAKE mixer. The resultant mixtures were further pressed to vulcanize at 140 °C, and vulcanized sheets were obtained. The vermiculite (VMT) was intercalated by cetyl-trimethylammonium bromide with a ball mill method to obtain used OVMT. The results showed that the intercalation led to an increase in the dfooj) of VMT from 1.46 nm to 4.51 nm. Meanwhile, they found that the tensile strength and the elongation at break of the NR/OVMT nanocomposites loading 15 phr of the OVMT reached 28.4 MPa and 623.2%, respectively. The 300% modulus, tear strength and hardness (Shore A) of the nanocomposites increased with the increase in OVMT loading. The thermal properties of the NR/OVMT nanocomposites were also improved. 

Figure 17.8 SEM (a) and TEM (b) pictures of a Lao,6Sro.4Coo.2Feo.B03 perovskite prepared by wet ball milling method. (Reprinted with permission from Ref. [29]. Copyright 2011, Elsevier.)...

---