Di-μ-hydroxido-bis-[di-bromido-(di-methyl-formamide-κO)ethyl-tin(IV)], [Sn2Br4(C2H5)2(OH)2(C3H7NO)2], was prepared from ethyl-tin(IV) bromide and N,N-di-methyl-formamide (DMF) in air. The crystal structure exhibits the typical structural features of dimeric Lewis-base-stabilized monoorganotin(IV)-dihalide-hydroxides, RSnHal2(OH), i.e. two octa-hedrally coordinated Sn atoms are linked together via two bridging hydroxide groups, resulting in a centrosymmetric four-membered rhomboid-like Sn-OH ring with acute angles at the Sn atom, obtuse angles at the O atoms and two different tin-oxygen bond lengths. With the shorter bond trans to the ethyl group, this observation underlines once more the so-called trans-strengthening effect in monoorganotin(IV) com-pounds with octa-hedrally coordinated Sn atoms. Differences and similarities in the bond lengths and angles in the four-membered Sn-OH rings have been worked out for the rings in dimeric diorganotin(IV)-halide-hydroxides, [R 2SnHal(OH)]2, and hydrates of dimeric tin(IV)-trihalide-hydroxide-aqua-hydrates, [SnHal3(OH)(H2O)]2·nH2O.

The triclinic structures of poly[(μ4-4,4\'-bi-phenyldi-carboxyl-ato)di-μ-hydroxido-dicobalt], [Co2(C14H8O4)(OH)2] n , and poly[(μ4-4,4\'-bi-phenyldi-carboxyl-ato)di-μ-hydroxido-dinickel], [Ni2(C14H8O4)(OH)2] n , were established using laboratory X-ray powder diffraction data. These structures, as well as that of poly[(μ4-4,4\'-bi-phenyldi-carboxyl-ato)di-μ-hydroxido-dimanganese], [Mn2(C14H8O4)(OH)2] n , were optimized using density functional techniques. The structure of di-ammonium 4,4\'-bi-phenyldi-carboxyl-ate, 2NH4 +·C14H8O4 2-, was also solved using laboratory powder data. The Mn and Co compounds are isostructural: the octa-hedral MO6 groups share edges to form chains running parallel to the c-axis. These chains share corners (OH groups) to link into layers lying parallel to the bc plane. The hydroxyl groups do not participate in hydrogen bonds. The structure of (NH4)2BPDC consists of alternating layers of BPDC and ammonium ions lying parallel to the ab plane. Each hydrogen atom of the ammonium ions in (NH4)2BPDC participates in a strong N-H⋯O hydrogen bond.

The crystal structure of poly[di-hydroxido(μ6-terepthalato)dizinc], [Zn2(C8H4O4)(OH)2] n , was solved and refined using synchrotron powder data, and the structures of the isostructural Co and Ni analogues were refined using laboratory powder X-ray data. The structure of [Co2(C8H4O4)(OH)2] n has been reported previously in space group C2/m, which yields disordered terephthalate anions. Doubling the c-axis of that cell results in an ordered model in space group C2/c. The octa-hedral MO6 coordination polyhedra of the metal cations share edges, forming chains running parallel to the b-axis direction. These chains share corners (hydroxyl groups), forming layers lying perpendicular to the a-axis direction.

The surface stoichiometry of the degraded surface of a commercial Al-Si casting was investigated. The die-cast component was previously stored in a sealed plastic envelope. After that, surface stains in the form of white layers were observed. X-ray photoelectron spectroscopy (XPS) was used to study these layers. For comparison, a seemingly unaffected area as well as a freshly cut surface of the casting were also analysed. In order to additionally assess the surface condition, surface roughnesses were measured. Based on the binding energies (BEs) of the Al and O in the XPS spectra, and the stoichiometric results, it was concluded that the surface layers of the degraded and undegraded samples consist mostly of aluminium oxide and aluminium hydroxide. Furthermore, sodium phosphate from the leftover detergent and silicon oxide were detected in both analysed areas. Analyses of the Al KLL Auger transition were used to corroborate this. The relative shares of Al oxide vs. hydroxide based on the elemental concentrations were determined. The chemical compositions and chemical states of the elements in the top layers were thus obtained. The combination of surface-sensitive analytical techniques was found to be a suitable tool for the ex-post identification of the source of defects.

Combining NaOH with other hydroxide bases with superior dissolution properties can be a means of improving dissolution of cellulose. However, this raises questions about how the size and structure of cellulose vary when dissolved in different hydroxide bases. Here, cellulose in aqueous solutions of NaOH, Tetramethylammonium hydroxide (TMAH), Benzyltrimethylammonium hydroxide (Triton B) and previously studied equimolar solutions of NaOH/TMAH and NaOH/Triton B were investigated using small angle X-ray scattering, static and dynamic light scattering. The results show that cellulose in NaOH(aq) is largely aggregated and that the more hydrophobic TMAH and Triton are capable of molecularly dissolving cellulose into worm-like conformations, stiffer than in NaOH. The dissolution properties of mixtures are highly dependent on the compatibility of the individual bases; in line with previous observations of the properties of the solutions which now could be correlated to the structure of the cellulose on a nano- and microscale.

The commonly reported calcination strategy usually requires high temperature to crack the metal-organic frameworks (MOFs) particles, which often lead to uncontrollable growth of nanomaterials. Here, for the first time, we utilize an electrochemical anion-exchanged method to control the hydrolysis of MOFs and synthesize porous Ni/Co hydroxide nanosheets. After the electrochemical anion-exchange, the organic ligands of MOFs nanosheets can be recycled and reused. Applying an electric field to the MOFs bulk in alkaline solution can accelerate the nucleation rate of hydroxide and change the migration behavior of charged ions/molecules, which can tailor the microstructure of derivatives and improve deep charge and discharge capability of the electrodes. As a result, the hydroxide with the optimized Ni:Co molar ratio of 7:3 and electric-field application time of 1000 cycles [Ni0.7Co0.3(OH)2-1000c] provides much better electrochemical properties than the materials synthesized without electric-field assistance: a high specific capacitance of 2115C g-1 (4230F g-1). A hybrid supercapacitor with the Ni0.7Co0.3(OH)2-1000c electrode shows a high energy density of 74.7 Wh kg-1, an improved power density (5,990.6 W kg-1), and an excellent cyclic stability (8,000 cycles). This study not only provides a novel strategy for the preparation of low-cost, deep-discharge electrodes for supercapacitors, but also proposes an unconventional method for mild synthesizing MOFs materials into porous nanoscale derivatives with tailored micromorphology.

Although electrode materials based on metal organic frameworks (MOFs) were widely studied in the electrochemistry field, the origin of poor conductivity is still a bottleneck restricting their development. Herein, we constructed a conductive circuit by growing a layer of hydroxide on the surface of the Fe-MOF, and composite materials (Fe-MOF@Ni(OH)2) are applied in the fields of supercapacitor, OER, and electrochemical sensing. Fe-MOF@Ni(OH)2 not only maintains the intrinsic advantages of Fe-MOF, but also improves the electrical conductivity. Fe-MOF@Ni(OH)2 exhibits a high specific capacity of 188 mAh g-1 at 1 A g-1 . The energy density of the asymmetric supercapacitor (Fe-MOF@Ni(OH)2-20//AC) reaches 67.1 Wh kg-1. During the oxygen evolution reaction, the overpotential of the material is 280 mV at 10 mA cm-2, and the Tafel slope is 37.6 mV dec-1. The electrochemical sensing tests showed the detection limit of BPA is 5 μM. Hence, these results provide key insights into the design of multifunctional electrode materials.

Converting wood waste into thermoplastic materials is an attractive means of increasing its utilization. A promising method for imparting thermoplasticity to wood is chemical modification, in which the hydroxyl groups in wood are substituted with benzyl groups. In the common method, wood powder is first treated with a highly concentrated aqueous NaOH solution, and then reacted with a benzylation reagent by heating for a long time under stirring. In this study, a 50% aqueous tetra-n-butylphosphonium hydroxide solution was used for the pretreatment of wood powder. This modified alkaline treatment enhanced the efficiency of the subsequent benzylation reaction, which could be conducted without heating over a shorter time. The effects of various conditions on the efficiency of the benzylation reaction were evaluated. Both the alkali pretreatment and the subsequent benzylation required only ~5-10 min of stirring without heating to obtain benzylated wood with a similar degree of benzylation as that achieved by the common method. The chemical structure of the benzylated wood powder was characterized by Fourier-transform infrared and solid-state NMR spectroscopies, and its thermal softening characteristics were evaluated by thermomechanical analysis. Finally, a translucent film could be obtained by hot-pressing the benzylated wood powder.

A dip-coating technique is designed for deposition of poly(methyl methacrylate) (PMMA) from water/2-propanol mixture, avoiding the use of traditional toxic solvents. Solutions of PMMA macromolecules with high molecular weight (MW) are obtained for a water/2-propanol ratio of 0.15-0.33 and the solubilization mechanism is discussed. The ability to use concentrated PMMA solutions and high MW of the polymer are the key factors for the successful dip coating deposition. The coating mass for 10 g L-1 polymer solutions shows a maximum at a water/2-propanol ratio of 0.25. The deposition yield increases with the polymer concentration increase and with an increasing number of the deposited layers. PMMA deposits protect stainless steel from aqueous corrosion. The coating technique allows for the fabrication of composite coatings, containing flame-retardant materials (FRMs), such as commercial halloysite, huntite, hydrotalcite, and synthesized Al(OH)3, in the PMMA matrix. The FRM content in the coatings is modified by variation of the FRM content in colloidal suspensions. A fundamentally new method is developed, which is based on the salting out aided dispersive extraction of Al(OH)3 from the aqueous synthesis medium to 2-propanol. It is based on the use of hexadecylphosphonic acid molecules as extractors. The method offers advantages of reduced agglomeration.

The unsatisfactory cycle life of nickel-based cathodes hinders the widespread commercial usage of nickel-zinc (Ni-Zn) batteries. The most frequently used methods to improve the cycle life of Ni-based cathodes are usually complicated and/or involve using organic solvents and high energy consumption. A facile process based on the hydrolysis-induced exchange of the cobalt-based metal-organic framework (Co-MOF) was developed to prepare aluminum (Al)-doped cobalt-nickel double hydroxides (Al-CoNiDH) on a carbon cloth (CC). The entire synthesis process is highly efficient, energy-saving, and has a low negative impact on the environment. Compared to undoped cobalt-nickel double hydroxide (Al-CoNiDH-0%), the as-prepared Al-CoNiDH as the electrode material displays a remarkably improved cycling stability because the Al-doping successfully depresses the transition in the crystal phase and microstructure during the long cycling. Benefiting from the improved performance of the optimal Al-CoNiDH electrode (Al-CoNiDH-5% electrode), the as-constructed aqueous Ni-Zn battery with Al-CoNiDH-5% as the cathode (Al-CoNiDH-5%//Zn) displays more than 14% improvement in the cycle life relative to the Al-CoNiDH-0%//Zn battery. Moreover, this Al-CoNiDH-5%//Zn battery achieves a high specific capacity (264 mAh g-1), good rate capability (72.4% retention at a 30-fold higher current), high electrochemical energy conversion efficiency, superior fast-charging ability, and strong capability of reversible switching between fast charging and slow charging. Furthermore, the as-assembled quasi-solid-state Al-CoNiDH-5%//Zn battery exhibits a decent electrochemical performance and satisfactory flexibility.