This review summarizes the recent research in preparing pharmaceutical formulations (co-amorphous, co-crystals, and polymorphs) through ball milling to enhance the …
tion has been observed by Richards et al. [17] in Cu-Ag alloys with a positive heat of mixing, as well as in a slow diffusing system V29Zr71 by Weeber et al. [18]. Amorphization of intermetallic ...
DOI: 10.1016/J.JNONCRYSOL.2006.09.021 Corpus ID: 94287931; Thermodynamic model for solid-state amorphization of pure elements by mechanical-milling @article{Zhao2006ThermodynamicMF, title={Thermodynamic model for solid-state amorphization of pure elements by mechanical-milling}, author={Yonghao Zhao}, …
Amorphous alloys prepared by milling following different reaction types are compared to each other and to the corresponding melt-spun alloys. Furthermore, criteria …
From the value of the enthalpy crystallization at the melting temperature determined from ACp andresults [9], we assume that the sample, after quenching treatment, is fully amorphous. 20 2 THETA /degree FIG. 4 Sucrose XRD patterns: a = crystalline, b = amorphous obtained by quenching, and c amorphous obtained by ball …
Abstract Amorphization via high energy ball milling is a solid state processing technique in which continuously moving balls transfer kinetic/impact energy to the powder ... [1–4]. In this review, the role of total milling energy and various milling parame-ters which inuences the milling energy have been discussed
1 Amorphization of different furosemide polymorphic forms during ball milling: tracking solid-to-solid phase transformations Mengwei Wang1,2, Junbo Gong2, Thomas Rades1*, Inês C. B. Martins1* 1 Department of Pharmacy, University of Copenhagen, Copenhagen, Denmark 2 State Key Laboratory of Chemical Engineering, School of Chemical …
Ball milling induced the formation of nanocrystalline and amorphization phase in Fe–25.68% Dy_2O_3 powder mixtures (mass fraction, %). The microstructure was investigated by using X-ray diffraction and transmission electron microscopy. The transformation of Dy_2O_3 from cubic to monoclinic crystal structure and then to the …
Semantic Scholar extracted view of "Amorphization of single composition powders by mechanical milling" by C. Koch. ... fracturing, and rewelding of powder particles in a high-energy ball mill. Originally developed to … Expand. 39. ... Amorphization by ball milling. A review. A. Weeber H. Bakker. Materials Science. 1988; 536.
The transformation of crystalline silicon to amorphous silicon during ball milling was quantitatively measured by x-ray diffraction and electrochemical methods. Amorphous silicon was found to form rapidly from the very initial stages of ball milling. Simultaneously, the grain size of the crystalline silicon phase decreased.
Three amorphization pathways were observed: i) crystalline form Ⅰ converts directly to an amorphous form; ii) crystalline form II converts into crystalline form I after 5 min of ball milling while at the same time form I and possibly form II (a small portion that did not convert to form I) progress towards complete amorphization during ball ...
Upon facile amorphisation by ball milling, the guest retention is greatly enhanced. Abstract The I 2 -sorption and -retention properties of several existing zeolitic imidazolate frameworks (ZIF-4, -8, -69) and a novel framework, ZIF-mnIm ([Zn(mnIm) 2 ]; mnIm=4-methyl-5-nitroimidazolate), have been characterised using microanalysis ...
Structural changes occurring in the crystalline element selenium upon high-energy ball milling has been studied. Milling experiments have been performed at the ambient temperature and at a cryogenic temperature of -100 ifmmode^circelsetextdegreefi{}C, respectively. The final milling products under both …
In this review, our focus is on amorphization induced by mechanical deformation which can be imparted by a variety of means, prominent among which are …
The microstructure of NiZr2 in the course of amorphization by ball-milling is studied by transmission electron microscopy (TEM) and x-ray diffraction (XRD). The evolution from the initial fully crystalline alloy to a fully amorphized material is described. It is shown that prior to amorphization, the powder aggregates achieve a …
Amorphization via high energy ball milling is a solid state processing technique in which continuously moving balls transfer kinetic/impact energy to the powder particles. It leads …
Amorphization of the FBZ by the Ball-mill Process (BM) A mixer mill (Retsch) model MM400, two 1.5-mL steel crushing vessels, and 3-mm diameter steel spheres were used for the FBZ amorphization. The proportion of 1/3 of the sample, 1/3 of spheres (around 25 spheres), and 1/3 of empty volumetric capacity were maintained.
It is found that Ni x Zr y compounds become fully amorphized provided the specific milling intensity is greater than a temperature- and composition-dependent threshold value. A vibrating frame grinder has been instrumented for evaluating the amplitude and frequency of ball oscillation, as a function of the amplitude of vibration of …
An intermetallic compound c –NiZr and a mixture of elemental powders of nickel and zirconium [Ni 50 Zr 50 (at. %)] have been mechanically ground (MG) and mechanically alloyed (MA), respectively, using a high-energy ball mill in various atmospheres. The products were characterized by x-ray diffraction, transmission electron microscopy, …
The kinetics of amorphization during ball milling is generally analyzed using two different approaches: the classical Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory and Delogu and Cocco's …
3. Emerging Pharmaceutical Techniques for Amorphization of Poorly Water-Soluble Drugs . In various attempts to overcome the limitations of PASDs, novel techniques such as co-amorphization, mesoporous particle-based amorphization, and in situ amorphization have been introduced (Figure 1).There are several reviews that …
The transformation of crystalline silicon to amorphous silicon during ball milling was quantitatively measured by x-ray diffraction and electrochemical methods. Amorphous silicon was found to form rapidly from the very initial stages of ball milling. Simultaneously, the grain size of the crystalline silicon phase decreased. Under …
We present a new approach, namely ball milling, to synthesize amorphous boron nitride (a-BN), The amorphization kinetics are revealed by X-ray diffractometry (XRD), high-resolution transmission electron microscopy (HRTEM), and electron energy loss spectroscopy (EELS), HRTEM investigations indicate that, in the early stage of …
Almost half of the oral administered commercial drugs have low solubility, which affects their bioavailability [1,2].Several alternatives to modify the supramolecular structure of APIs have been proposed to overcome their low solubility; these strategies include amorphization [3,4,5], solid dispersion [6,7,8,9], preparation of co-crystals [10,11], and polymorphs …
In addition to previously reported techniques for making amorphous ices, ball milling is an established technique for making amorphous materials in general ().This method is widely used for …
Mechanical Activation by Ball Milling as a Strategy to Prepare Highly Soluble Pharmaceutical Formulations in the Form of Co-Amorphous, Co-Crystals, or Polymorphs ... such as the amorphization and preparation of co-crystals or polymorphs. Since many APIs are thermosensitive, non-thermal emerging alternative techniques, …
The ordered fcc intermetallic compound Ni_3Al was mechanically milled in a high energy ball mill. The severe plastic deformation produced by milling induced transformations with increasing milling time as follows: ordered fcc → 2; disordered fcc → 2; nanocrystalline fcc + amorphous. The milling time for complete disordering occurred at 5 h for …
The present review provides a comprehensive understanding of various HEAs produced by MA so far, with the aim to bring out the governing aspects of phase evolution, thermal stability, and properties achieved. The limitations and challenges of the process are also critically assessed with a possible way forward.
Effect of Milling Parameters and Milling Energy on Amorphization: A Review. A. Sahu L. Singh R. S. Maurya. Materials Science, Engineering. Transactions of the Indian Institute of Metals. 2023; Amorphization via high energy ball milling is a solid state processing technique in which continuously moving balls transfer kinetic/impact …
Amorphization of metallic titanium by ball milling was presented. With the introduction of continuous pickup of impurities, hexagonally close-packed (hcp) titanium transformed gradually into an amorphous phase without experiencing any intermediate stage of forming a detectable metastable compound phase. The crystallization …
In this review, our focus is on amorphization induced by mechanical deformation which can be imparted by a variety of means, prominent among which are tribological processes, severe plastic deformation, nanoindentation, shock compression, diamond anvil cell and ball milling/mechanical alloying. The deformation introduces …
