In this study, zinc borate (ZB) was synthesized by reacting zinc oxide and boric acid in the presence of standard ZB (w/w, in terms of boric acid) in order to promote crystallization. The effects of seed, H₃BO₃/ZnO (boric acid/zinc oxide) ratio, reaction time, water volume, reaction temperature and cooling temperature on yield were investigated for pilot-scale equipment. The results indicated that the addition of seed (w/w) to a saturated solution of reactants increased the yield of the reaction. The results of reaction yields obtained from either magnetically or mechanically stirred systems were compared. At various reaction times, the optimal yield was 86.78 % in a saturated aqueous solution. The products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Thermogravimetric / Differential Thermal Analysis (TG/DTA). The results displayed that ZB was successfully produced under the optimized reaction conditions and the product synthesized had high thermal stability.

DOI: http://dx.doi.org/10.5755/j01.ms.19.2.4432

No abstract

Streszczenie Celem tego artykułu jest synteza boranu cynku przy użyciu węglanu cynku, kwasu borowego, referencyjnego boranu cynku (ZB) jako substancji aktywnej oraz badanie efektywności tego procesu modyfikowanego odczynnikami i parametrami reakcji na hydrofobowość i wydajność syntezy boranu cynku. Dotyczy to działania różnych czynników modyfikujących hydrofobowość i parametry reakcji: glikol propylenowy (PG) (0−6%, kerozyna 1−6%, kwas oleinowy (OA) 1−6% oraz rozpuszczalniki: alkohol izopropylowy (IPA), etanol i metanol. Po pierwsze, badano jak wpływają następujące parametry reakcji na uzysk boranu cynku: czas reakcji (1−5 h), wskaźnik reaktywacji (H3BO3 : ZnO), (2−5), udział zarodków krystalizacji (0−1,5%) w odniesieniu do kwasu borowego, temperatura reakcji (50−120°C), temperatura chłodzenia (10−80 °C), szybkość mieszania (400−700 obr./min). Ponadto, reakcje były przeprowadzone w określonych warunkach mieszania mechanicznego i magnetycznego. Wytwarzany boran cynku ze względu na hydrofobowość badano metodami: dyfrakcji rentgenowskiej XRD, spektroskopii FT-IR oraz pomiarami kąta zwilżania. Reasumując, stwierdzono, że boran cynku można otrzymać z powodzeniem z różnymi rozpuszczalnikami wpływającymi na jego hydrofobowość.

In general, zinc oxide and boric acid are used to produce zinc borate. In this study, zinc carbonate was used instead of zinc oxide as the novel zinc source. The purpose of this study was to synthesize hydrophobic, nanostructured zinc borate (3ZnOÁ3B 2 O 3 Á3.5H 2 O) by reaction of zinc carbonate, instead of zinc oxide, with boric acid reference material, and with zinc borate reference material as seed. The modifying agents propylene glycol, kerosene, and oleic acid were used to produce hydrophobic zinc borate. Different solvents (isopropyl alcohol, ethanol, and methanol) were used to obtain a homogeneous phase. The effects of different modifying agents and solvents on the hydrophobicity and nanostructure of the product were investigated. The synthesized zinc borate was characterized by X-ray diffraction and Fourier-transform infrared spectroscopy. Contact angles were measured to determine the hydrophobicity of the products and scanning electron microscopy was used to study both the morphology and nanostructure of the products. Hydrophobic, nanostructured zinc borate was successfully produced by use of zinc carbonate instead of zinc oxide as the novel zinc source. Use of different modifying agents and solvents affected both hydrophobicity and nanostructure.