The application of a technique to eliminate the latent period during crystallization of sucrose by high intensity ultrasound (HIU) was investigated in this paper. Employing HIU (20 kHz, 750 W) to crystallization of sucrose, latent period was eliminated and it was found to obey first order kinetics (K ∼10s) in the temperature range of 30-50 °C. Employing Arrhenius equation, the average energy of activation (E) estimated as 5.0 kcal mol. Traditional knowledge indicates that crystallization is sufficiently spontaneous; however, the magnitude of "K" and other thermodynamic quantities of the process indicate that crystallization is actually a slow process. Generally, chemical reactions which posses low rate constants, need the high energy of activation. On the contrary, the energy of activation is appreciably less. The energy of activation with a rate constant of the order of 10s could be predicted of the order of 20 kcal mol at 27 °C. The low energy of activation for crystallization of sucrose is of interest. A very interesting elucidation can be had from neutron diffraction data and transport property of the sucrose which is discussed in details in this paper.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ultsonch.2018.05.030DOI Listing

Publication Analysis

Top Keywords

energy activation
20
crystallization sucrose
16
latent period
12
high intensity
8
intensity ultrasound
8
ultrasound hiu
8
crystallization
6
sucrose
5
energy
5
activation
5

Similar Publications

Unraveling the Trade-Off Effect of Pyrogenic Carbons Between Biopseudocapacitors and Bioconductors During Anaerobic Methanogenesis.

Environ Sci Technol

January 2025

State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, PR China.

Pyrogenic carbons (PCs), with varying structures depending on the materials and thermal treatment conditions, have been extensively used to enhance anaerobic digestion by mediating electron transfer. However, the underlying mechanism has yet to be explored. Herein, the redirection and enhancement of the direct interspecies electron transfer (DIET) pathway were evidenced, along with the upregulated electrochemical properties and structural proteins in the methanogenic consortia.

View Article and Find Full Text PDF

In this study, a novel hybrid nanostructure consisting of acid-decorated chitosan and magnetic AlFeO nanoparticles was fabricated. The acid-decorated chitosan provided a stable and biocompatible matrix for the magnetic AlFeO nanoparticles. Various techniques including Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction patterns (XRD), thermogravimetric analysis (TGA), vibrating sample magnetometry (VSM), specific surface area (BET), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS) were used to characterize and confirm the successful synthesis of the hybrid nanostructure.

View Article and Find Full Text PDF

Polycyclic aromatic compounds (PACs) are pervasive environmental contaminants derived from diverse sources including pyrogenic (e.g., combustion processes), petrogenic (e.

View Article and Find Full Text PDF

In the manufacturing of some sectors, such as marble and brick, certain byproducts, such as sludge, powder, and pieces containing valuable chemical compounds, emerge. Some concrete plants utilize these byproducts as mineralogical additives in Turkey. The objective of the experimental study is to ascertain whether the incorporation of waste from the marble and brick industries, in powder form, into cement manufacturing as a mineralogical additive or substitute is a viable option.

View Article and Find Full Text PDF

Piezoelectric catalysis possesses the potential to convert ocean wave energy into and holds broad prospects for extracting uranium from seawater. Herein, the Z-type ZnO@COF heterostructure composite with excellent piezoelectric properties was synthesized through in situ growth of covalent organic frameworks (COFs) on the surface of ZnO and used for efficient uranium extraction. The designed COFs shell enables ZnO with stability, abundant active sites and high-speed electron transport channels.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!