Vpliv diskretne razporeditve naboja na silo med nabitimi nanodelci

Štefanič, Zala (author), Reščič, Jurij (mentor)

V diplomski nalogi smo izvedli Monte Carlo (MC) simulacije na ionskih sistemih med dvema zporednima zvezno in diskretno nabitima površinama. Tak sistem je približek, ki nam omogoča vpogled v interakcije med nabitimi delci. S simulacijami smo želeli ugotoviti, kako diskretizacija naboja na površinah vpliva na silo med dvema delcema v primerjavi s silo pri zvezni nabitosti. Preverili smo tudi, ali imajo različne vrste diskretizacije različen vpliv na silo. Pri diskretni razporeditvi naboja se na površini delcev gosto naberejo protiioni, zaradi česar bi pričakovali manjši odboj med delcema. Izračun osmotskega tlaka na podlagi kontaktnih vredosti koncentracijskih profilov protiionov pa je namesto tega prikazal močno odbojno silo. Na podlagi tega lahko sklepamo o neustreznosti te enačbe pri opisovanju modelov, kjer se na površini delca nahaja diskretno razporejen naboj. Med zvezno nabitimi stenami smo v skladu s teorijo pri ustreznih pogojih opazili efektivno privlačno silo. Za manjše diskretne naboje, ki so po površini razpršeni tako, da posnemajo zvezno razporeditev, smo opazili veliko ujemanje z zvezno razporeditvijo med tlaki in koncentracijskimi profili. Večjih razlik med mrežno in naključno mobilno razporeditvijo nismo opazili.

• Language: Slovenian
• Keywords: MC simulacije, diskretizacija naboja, DLVO teorija
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2020
• PID: 20.500.12556/RUL-119658
• COBISS.SI-ID: 30002691
• Publication date in RUL: 10.09.2020

ŠTEFANIČ, Zala, 2020, Vpliv diskretne razporeditve naboja na silo med nabitimi nanodelci [online]. Bachelor’s thesis. [Accessed 1 June 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=119658

Secondary language

• Language: English
• Title: The influence of discrete charges on the force between charged nanoparticles

Abstract

In this diploma thesis, Monte Carlo (MC) simulations for an ionic system between two parallel uniformly and discretely charged plates were performed. This model system is an approximation which enables the study of interactions between same charged particles. The simulations were used to illustrate the differences that occur when discrete charge is introduced in place of a uniform charge. It was our aim to also test how different patterns of discrete charge influence the force. With discrete charge, counterions concentrate more towards the charged walls inducing a weaker repulsive force compared to the one observed for uniform charge. Calculations of pressure, based on the contact concentrations of counterions, however, predicted an even stronger repulsion. We must therefore conclude that for discretely charged particles this approach is unsuitable for the prediction of particle interactions. At suitable conditions, however, the same method was successful in predicting an effective attractive force for uniformly charged particles. When compared, smaller dispersed discrete charge (resembling the uniform charge) produced a strong similarity for both pressure and the concentration profiles to that of the uniform charge. We found no significant difference between the different discrete patterns of charge.

• Keywords: MC simulations, discrete charge, DLVO theory