Vortex-layer devices as import-substituting equipment to produce paints and adhesives

It is proposed to use domestically produced vortex layer devices instead of imported bead mills for grinding pigments (and the synthesis of some of them) in the paint industry, for preparation of intermediates of film formers for the reduction of aromatic nitro-compounds to primary amines used as curing agents for epoxy oligomers, in the synthesis of dyes, etc. It is shown that using these devices results in not only technological advantages over bead mills, but will also allow us to replace some types of imported raw materials.     

机械研磨时间对铜基甲醇合成催化剂性能的影响

采用机械研磨燃烧法在不同研磨时间下制备了系列Cu/ZnO/Al2O3催化剂,并评价了其在一氧化碳加氢制备甲醇反应中的活性。催化剂前驱体的焙烧过程通过热重-差热分析仪(TG-DSC)监测。采用X射线衍射(XRD)、扫描电镜(SEM)、N2吸附、程序升温还原(TPR)和N2O氧化后氢气滴定等方法对催化剂进行了表征。结果表明,催化剂的结构性质与研磨时间密切相关,催化剂的比表面积和铜原子的分散度随研磨时间延长先增大后减小,研磨2 h制得的催化剂显示了最高的催化活性。     

Vortex grinding for mechanochemistry: application for automated supramolecular catalysis and preparation of a metal-organic framework

An automated grinding method based on a vortex mixer has been developed. The method enables simultaneous grinding and UV-irradiation, as well as in situ monitoring of solid-state reactivity. The method has been applied to a cocrystallization, supramolecular catalysis, and the preparation of a metal-organic framework.     

Hydration-Facilitated Fine-Tuning of the AIE Amphiphile Color and Application as Erasable Materials with Hot/Cold Dual Writing Modes

Hydration water greatly impacts the color of inorganic crystals, but it is still unknown whether hydration water can be utilized to systematically manipulate the emission color of organic luminescent groups. Now, metal ions with different hydration ability allow fine-tuning the emission color of a fluorescent group displaying aggregation induced emission (AIE). Because the hydration water can be removed easily by gentle heating or mechanical grinding and re-gained by solvent fuming, rewritable materials can be fabricated both in the hot-writing and cold-writing modes. This hydration-facilitated strategy will open up a new vista in fine-tuning the emission color of AIE molecules based on one synthesis and in the design of smart luminescent devices.     

Screening for crystalline salts via mechanochemistry

Neat grinding and solvent-drop grinding methods are found to be effective screening tools for indicating the potential for crystalline salt formation involving a given acid-base pair, as demonstrated with two model pharmaceuticals.     

Improvements in the Grinding of Gold-Bearing Geochemical Samples and Their Sampling for Fire Assay

The effect of fine grinding of gold-bearing geochemical samples on the representative sample size and the recovery of gold and silver in fire-assay fusion was studied experimentally. A method is proposed for the improvement of grinding and sampling procedures in fire assay.     

Hydration‐Facilitated Fine‐Tuning of the AIE Amphiphile Color and Application as Erasable Materials with Hot/Cold Dual Writing Modes

Hydration water greatly impacts the color of inorganic crystals, but it is still unknown whether hydration water can be utilized to systematically manipulate the emission color of organic luminescent groups. Now, metal ions with different hydration ability allow fine‐tuning the emission color of a fluorescent group displaying aggregation induced emission (AIE). Because the hydration water can be removed easily by gentle heating or mechanical grinding and re‐gained by solvent fuming, rewritable materials can be fabricated both in the hot‐writing and cold‐writing modes. This hydration‐facilitated strategy will open up a new vista in fine‐tuning the emission color of AIE molecules based on one synthesis and in the design of smart luminescent devices.     

Blue electroluminescence of a novel Zn~(2+)–β-diketone complex with a carbazole moiety

In this letter, a novel zinc complex of Zn(ECTFBD)2 was synthesized by an environment-friendly grinding technique in high yield. Its structure was confirmed by1H NMR, MS and EA. HECTFBD is 1-(9-ethyl-9Hcarbazol-3-yl)-4,4,4-trifluorobutane-1,3-dione. Zn(ECTFBD)2-based light-emitting devices were fabricated. The architecture of the devices was ITO/PEDOT(40 nm)/100 wt% PVK: 40 wt% OXD-7: x wt% Zn(ECTFBD)2(85 nm)/CsF(1.5 nm)/Al(100 nm), where x = 1, 5, and 10(relative to the mass of PVK and OXD-7). The three devices displayed blue emissions with peaks at 450, 458, and 460 nm, respectively. A maximum luminous efficiency of 0.86 cd/A and a luminance of 228 cd/m2were achieved by the 1 wt% doped device. So, we demonstrated further that Zn2+–b-diketone complexes can be effectively severed as a class of new electroluminescent materials. In addition, the thermal stability of Zn(ECTFBD)2 was tested and the UV–vis and photoluminescent behaviors of Zn(ECTFBD)2 in CH2 Cl2 were investigated.     

Organic materials with hydrostatic pressure induced mechanochromic properties

Mechanochromic organic materials are a typical class of stimuli materials that has response to external physical stimuli such as shearing, grinding, and compressing etc. Organic compounds with mechanochromic characters in solid forms have attracted significant attention in the past decades due to their potential applications in sensors and memory devices. Diamond anvil cell is an emerging technology that can provide isotropic pressure in a tiny place. Thus a new stimuli method can be applied in investigating optical variation of mechanochromic materials. In this review, we focus on mechanoluminescence systems that are responsive to isotropic compression under high pressure and summarize the recent advances on organic materials studied by the diamond anvil cell.     

Evaluation of sample preparation (grinding and sieving) of bivalves, coffee and cowpea beans for multi-element analysis

Elemental analyses of food samples require several pre-treatment steps that constitute a great potential source of errors. In this study, the influence of cryogenic, ball and knife mill devices and also sieving using different sizes of sieve (100, 300 and 500 μm) was evaluated for samples of bivalves, coffee and cowpea beans. A two-factor ANOVA was performed in each sample to test for differences between macro, micro and trace element concentrations determined by ICP OES. Results showed that the efficiency of the particle size reduction and sample homogeneity depends on the milling device and the nature of samples. Food samples may present segregation after comminution, and sieving might become a necessary step. Nevertheless, the sieve aperture has to be chosen cautiously, once it might influence the final element concentration. Overall, the expected results by employing cryogenic grinding, such as rapid sample homogenization and small particle size generated were also observed for ball mill. Contamination can be a critical issue for some elements and need to be evaluated individually.     

Significance of fatigue for mechanical defibration

The fatigue induced by high-frequency cyclic loading on the compressibility and tensile properties of wood and wood cell walls was quantified. The non-elastic behavior of fatigued and reference samples was similar, whereas their elastic behavior differed, as expected. Next, the effects of the dynamic fatigue on the mechanical pulping process were quantified by grinding fatigued and untreated samples and by comparing the paper strength produced by the two pulps against the consumed pulping energy. Pre-introducing fatigue increased the energy efficiency of grinding and may allow designing a more energy efficient mechanical pulping process.     

Mechanochemical and Size Reduction Machines for Biorefining

In recent years, we have witnessed an increasing interest in the application of mechanochemical methods for processing materials in biomass refining techniques. Grinding and mechanical pretreatment are very popular methods utilized to enhance the reactivity of polymers and plant raw materials; however, the choice of devices and their modes of action is often performed through trial and error. An inadequate choice of equipment often results in inefficient grinding, low reactivity of the product, excess energy expenditure, and significant wear of the equipment. In the present review, modern equipment employing various types of mechanical impacts, which show the highest promise for mechanochemical pretreatment of plant raw materials, is examined and compared—disc mills, attritors and bead mills, ball mills, planetary mills, vibration and vibrocentrifugal mills, roller and centrifugal roller mills, extruders, hammer mills, knife mills, pin mills, disintegrators, and jet mills. The properly chosen type of mechanochemical activation (and equipment) allows an energetically and economically sound enhancement of the reactivity of solid-phase polymers by increasing the effective surface area accessible to reagents, reducing the amount of crystalline regions and the diffusion coefficient, disordering the supramolecular structure of the material, and mechanochemically reacting with the target substances.     

A method for preparation of magnetizable cellulose and its application in radioimmunoassays for T3 and T 4 1

An easy adoptable technique has been developed to prepare magnetizable cellulose by the process of wet grinding of a mixture of iron oxide (magnetite) and cellulose in a stirred ball mill. Anti rabbit IgG was covalently coupled to this magnetizable cellulose. The immunosorbent thus prepared has been used in radioimmunoassays of T₃ and T₄ for the separation of bound and free antigens. The reliability of the above immunosorbent has been validated by studying assay parameters such as non-specific binding (NSB), maximum binding (B ₀), CV etc. The single step process of wet grinding adopted here not only firmly binds magnetite and cellulose physically, but also lowers the size of the resulting magnetizable cellulose. The conventional method of preparation involves the coprecipitation of cellulose dissolved in cuprammonium hydroxide solution along with iron oxide, followed by extensive grinding and sieving of the iron oxide impregnated cellulose.     

A practical grinding-assisted dry synthesis of nanocrystalline NiMoO4 polymorphs for oxidative dehydrogenation of propane

A practical two-stage reactive grinding-assisted pathway waste-free and cost-effective for the synthesis of NiMoO₄ has been successfully developed. It was demonstrated that proper design in synthetic strategy for grinding plays a crucial role in determining the ultimate polymorph of NiMoO₄. Specifically, direct grinding (DG) of MoO₃ and NiO rendered α-NiMoO₄ after annealing, whereas sequential grinding (SG) of the two independently pre-ground oxides followed by annealing generated β-NiMoO₄ solid solution. Characterizations in terms of Raman and X-ray diffraction suggest the creation of β-NiMoO₄ precursor in the latter alternative is the key aspect for the formation of β-NiMoO₄. The DG-derived α-NiMoO₄ tested by oxidative dehydrogenation of propane exhibited superior activity in contrast to its analog synthesized via conventional coprecipitation. It is suggested that the favorable chemical composition facilely obtained via grinding in contrast to that by coprecipitation was essential for achieving a more selective production of propylene.     

某矿山金矿石样品加工及分析方法优化研究

某矿山金矿石样品中存在中粗颗粒金,颗粒金的存在将对分析样品的均匀性和代表性产生影响。通过棒磨、密封粉碎及盘磨等方式研究,选择出最优的样品加工方式,同时通过分析方法比对,选择出最优的样品分析方法。实验确定金矿石采用圆盘细碎机加工至样品粒度不大于0.074 mm,混匀后即获得分析试样。分析试样经王水消解后采用泡沫吸附进行富集,火焰原子吸收光谱法测定。通过研究,取得最优的金矿样品加工和分析方案,为某矿山提供了高品质的金储量评估数据。     

关于澳洲GoLden Grove金精矿磨样方法的研究

金精矿样品的粒度,直接影响金精矿中金含量测定的精密度和稳定性,本文通过对Golden Grove金精矿采用不同的磨样工具和磨样时间,得到不同粒度的样品,对不同样品进行了金含量的测定,并对测定结果的精密度进行了分析。其中磨样方式：滚筒磨样机、磨样时间为5h、磨样粒度为0.040mm(360目)95%以上的B样品,测定精密度最好。C样品测定精密度相对较差,反映出振动粉碎机磨样均匀度相对较差。     

Aggregation-induced phosphorescence and mechanochromic luminescence of a tetraphenylethene-based gold(I) isocyanide complex

In this study, a new twisting gold(I) isocyanide complex based on tetraphenylethene (TPE), TPE-NC-Au, was designed and synthesized. It exhibits aggregation induced phosphorescence (AIP) characteristics, owing to the incorporation of Au moiety and conformation rigidification in the aggregated states. Moreover, the emission color of the crystalline solid of TPE-NC-Au changes from blue (454 nm) to green (500 nm) in response to mechanical grinding, due to the combined effects of conformation planarization, enhanced π…π stacking, as well as the emergence of aurophilic interactions in the ground amorphous state. Notably, the emission color can be restored upon solvent fuming, associating with the reconstruction of crystalline lattices. The AIP and switchable mechanochromism of TPE-NC-Au make it suitable for potential applications in bioimaging, sensing, and optoelectronic devices.     

Study of contamination sources in the process of cryogenic grinding

The study of contamination effect during cryogenic grinding of pure cellulose was carried out. The optimisation of important parameters of the grinding process (pre-cooling time, grinding time, cooling time and number of cycles) was performed and the different sources of a possible contamination of samples (earlier processed sample, metal parts of grinding tool) were evaluated. The results of ICP-oa-TOF MS analysis after microwave digestion of cellulose samples were used in this study. Significant contamination of cellulose samples by Fe at the level 130 microg kg(-1) caused by wearing of steel stoppers and an impact bar was detected. Cross-contamination by Fe, Cr, Mn and Cu at the level 400, 200, 200 and 2100 microg kg(-1), respectively was caused by previous grinding of electro-waste sample. This cross-contamination was possible to be avoided by changing of a polycarbonate part of a grinding vessel.     

Contamination of Rock Samples by Laboratory Grinding Mills

We have measured the contamination of samples of granite, quartz porphyry, greenstone and dolerite after grinding them in steel and cemented carbide grinding mills. The steel mill contaminated the granite with Fe. The cemented carbide mill contaminated all samples with W and Co, and the granite and quartz porphyry with Ta. Contamination during grinding is proportional to the free quartz content of the rock and to the grinding time.     

Small‐Sized Tungsten Nitride Particles Strongly Anchored on Carbon Nanotubes and their Use as Supports for Pt for Methanol Electro‐oxidation

The anchoring of small‐sized WN (tungsten nitride) nanoparticles (NPs) with good dispersion on carbon nanotubes (CNTs) offers an effective means of obtaining promising materials for use in electrocatalysis. Herein, an effective method based on grinding treatment followed by a nitridation process is proposed to realize this goal. In the synthesis, a solution containing H₄[SiO₄(W₃O₉)₄] (SiW₁₂) and CNTs modified with polyethylenimine (PEI‐CNTs) was ground to dryness. Small‐sized WN NPs were anchored onto the CNTs with good dispersion after calcination under NH₃. Under hydrothermal assembly conditions (absence of grinding), WN particles of larger size and with inferior dispersion were obtained, demonstrating the important role of the grinding process. The benefit of the small‐sized WN has been demonstrated by using WN/CNTs as a support for Pt to catalyze the methanol electro‐oxidation reaction. The mass activity of Pt‐WN/CNTs‐G‐70 (where G denotes the grinding treatment, and 70 is the loading amount (%) of WN in the WN/CNTs) was evaluated as about 817 mA mg^?1_Pt, better that those of commercial Pt/C (340 mA mg^?1_Pt) and Pt/CNTs (162 mA mg^?1_Pt). The Pt‐WN/CNTs‐G also displayed good CO tolerance. In contrast, Pt‐WN/CNTs prepared without the grinding process displayed an activity of 344 mA mg^?1_Pt, verifying the key role of grinding treatment in the preparation of WN/CNTs with good co‐catalytic effect.