TY  - JOUR
AU  - Trifunović, Saša
AU  - Miličević, Dejan
AU  - Mićić, Maja
AU  - Mudrinić, Tihana
AU  - Suljovrujić, Edin
PY  - 2011
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/7024
AB  - U ovom radu ispitivan je uticaj prirodnog starenja na morfološke i optičke karakteristikeTPD (N,N’-bis(3-metilfenil)-N,N’-difenilbenzidin) tankih filmova. Inicijalno, filmovi su pripremljeni fizičkom vakuumskom depozicijom pare, sa kosinusnom raspodelom debljine duž monokristalne SiO2 podloge. Morfologija tankih filmova proučavana je optičkom (OM) i „atomic force“ (AFM) mikroskopijom. Prostorno korelisana morfološka (AFM i OM) i optička (apsorbanca i fotoluminescencija) merenja primenjena su za određivanje uzajamne veze optičkih osobina i različitih morfologija filma. Promene u apsorpcionim i fotoluminescentnim spektrima čvrsto su povezane sa promenama u mikrostrukturi nastalim starenjem filmova. Bez obzira na morfološke i razlike u debljini filma (za dva reda veličine) svi filmovi neposredno nakon deponovanja pokazuju amorfno uređenje. Odležavanjem ovih filmova u normalnim atmosferskim uslovima (prirodno starenje) uočavaju se kako morfološke tako i promene u optičkim osobinama izazvane kristalizacijom. Svojstvo amorfnih TPD filmova da kristališu je takođe potvrđeno i diferencijalnom skanirajućom kalorimetrijom (DSC). Svi rezultati ukazuju na ograničenu mogućnost upotrebe TPD filmova u organskim elektroluminescentnim uređajima.
AB  - This paper presents the influence of ageing on the morphological and optical properties of TPD (N,N’-bis(3-methylphenil)-N,N’- diphenylbenzidine) thin films. Understanding of the nucleation mechanism and growth dynamics of molecular thin films is pivotal for controlling their morphology and the film interfacial properties, while the influence of ageing is essential for the potential commercial utilization. Initially, thin films were prepared using a combinatorial physical vapour deposition (CPVD) method, following a cosine-like distribution profile of thickness along monocrystal silica substrate. Morphology of thin films was investigated by using optical (OM) and atomic force microscopy (AFM). The link between optical properties and the resulting thin film morphology was made by spatially correlated morphological (AFM and OM) and optical (absorption and photoluminescence) measurements. The changes in the absorption and photoluminescence spectra are strongly connected to the ageing-induced changes in the microstructure of thin films. Regardless of morphological and differences in the film thickness (two orders of magnitude), all films show amorphous arrangement just after the deposition. Ageing of these films in regular atmosphere conditions results in morphological and changes in optical properties induced by the crystallization. The crystallization of initially amorphous samples was also confirmed by the differentional scanning calorimetry (DSC) measurements. All results indicate the limited possibility of using TPD films in organic electroluminescent devices.
PB  - Association of Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Uticaj starenja na morfološke i optičke karakteristike tankih filmova
T1  - The Influence of Ageing on the Morphological and Optical Properties of Thin Tpd Films
VL  - 65
IS  - 1
SP  - 9
EP  - 13
DO  - 10.2298/HEMIND100519062T
ER  - 

@article{
author = "Trifunović, Saša and Miličević, Dejan and Mićić, Maja and Mudrinić, Tihana and Suljovrujić, Edin",
year = "2011",
abstract = "U ovom radu ispitivan je uticaj prirodnog starenja na morfološke i optičke karakteristikeTPD (N,N’-bis(3-metilfenil)-N,N’-difenilbenzidin) tankih filmova. Inicijalno, filmovi su pripremljeni fizičkom vakuumskom depozicijom pare, sa kosinusnom raspodelom debljine duž monokristalne SiO2 podloge. Morfologija tankih filmova proučavana je optičkom (OM) i „atomic force“ (AFM) mikroskopijom. Prostorno korelisana morfološka (AFM i OM) i optička (apsorbanca i fotoluminescencija) merenja primenjena su za određivanje uzajamne veze optičkih osobina i različitih morfologija filma. Promene u apsorpcionim i fotoluminescentnim spektrima čvrsto su povezane sa promenama u mikrostrukturi nastalim starenjem filmova. Bez obzira na morfološke i razlike u debljini filma (za dva reda veličine) svi filmovi neposredno nakon deponovanja pokazuju amorfno uređenje. Odležavanjem ovih filmova u normalnim atmosferskim uslovima (prirodno starenje) uočavaju se kako morfološke tako i promene u optičkim osobinama izazvane kristalizacijom. Svojstvo amorfnih TPD filmova da kristališu je takođe potvrđeno i diferencijalnom skanirajućom kalorimetrijom (DSC). Svi rezultati ukazuju na ograničenu mogućnost upotrebe TPD filmova u organskim elektroluminescentnim uređajima., This paper presents the influence of ageing on the morphological and optical properties of TPD (N,N’-bis(3-methylphenil)-N,N’- diphenylbenzidine) thin films. Understanding of the nucleation mechanism and growth dynamics of molecular thin films is pivotal for controlling their morphology and the film interfacial properties, while the influence of ageing is essential for the potential commercial utilization. Initially, thin films were prepared using a combinatorial physical vapour deposition (CPVD) method, following a cosine-like distribution profile of thickness along monocrystal silica substrate. Morphology of thin films was investigated by using optical (OM) and atomic force microscopy (AFM). The link between optical properties and the resulting thin film morphology was made by spatially correlated morphological (AFM and OM) and optical (absorption and photoluminescence) measurements. The changes in the absorption and photoluminescence spectra are strongly connected to the ageing-induced changes in the microstructure of thin films. Regardless of morphological and differences in the film thickness (two orders of magnitude), all films show amorphous arrangement just after the deposition. Ageing of these films in regular atmosphere conditions results in morphological and changes in optical properties induced by the crystallization. The crystallization of initially amorphous samples was also confirmed by the differentional scanning calorimetry (DSC) measurements. All results indicate the limited possibility of using TPD films in organic electroluminescent devices.",
publisher = "Association of Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Uticaj starenja na morfološke i optičke karakteristike tankih filmova, The Influence of Ageing on the Morphological and Optical Properties of Thin Tpd Films",
volume = "65",
number = "1",
pages = "9-13",
doi = "10.2298/HEMIND100519062T"
}

Trifunović, S., Miličević, D., Mićić, M., Mudrinić, T.,& Suljovrujić, E.. (2011). Uticaj starenja na morfološke i optičke karakteristike tankih filmova. in Hemijska industrija
Association of Chemical Engineers of Serbia., 65(1), 9-13.
https://doi.org/10.2298/HEMIND100519062T

Trifunović S, Miličević D, Mićić M, Mudrinić T, Suljovrujić E. Uticaj starenja na morfološke i optičke karakteristike tankih filmova. in Hemijska industrija. 2011;65(1):9-13.
doi:10.2298/HEMIND100519062T .

Trifunović, Saša, Miličević, Dejan, Mićić, Maja, Mudrinić, Tihana, Suljovrujić, Edin, "Uticaj starenja na morfološke i optičke karakteristike tankih filmova" in Hemijska industrija, 65, no. 1 (2011):9-13,
https://doi.org/10.2298/HEMIND100519062T . .

TY  - JOUR
AU  - Miličević, Dejan
AU  - Trifunović, Saša
AU  - Mudrinić, Tihana
AU  - Leskovac, Andreja
AU  - Ignjatović, Nenad
AU  - Dojčilović, Jablan
AU  - Suljovrujić, Edin
PY  - 2010
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/7023
AB  - U ovom radu ispitivan je uticaj gama zračenja na molekulsku masu i staklasti prelaz poli-L-laktida (PLLA). S obzirom da je PLLA pri izlaganju visokoenergijskom zračenju sklon kidanju lanaca i velikoj degradaciji, promene u molekulskoj masi su određene primenom gel propusne hromatografije (GPC). Radijaciono-indukovane promene u staklastom prelazu su ispitane pomoću diferencijalno skenirajuće kalorimetrije (DSC). Prividna aktivaciona energija za staklasti prelaz, ΔH*, određena je na osnovu zavisnosti temperature staklastog prelaza, Tg, od brzine zagrevanja. Kidanje lanaca, uzrokovano zračenjem, glavni je razlog opadanja Tg i ΔH* sa apsorbovanom dozom. Izazvane promene u molekulskoj masi i temperaturi staklastog prelaza odigravaju se na predvidljiv i prilično precizan način. Stoga, gama zračenje može biti korišćeno nesamo za sterilizaciju nego i za dobijanje ovog biomaterijala poželjnih karakteristika.
AB  - The influence of gamma radiation on the structure and glass transition behaviour of poly-L-lactide (PLLA) has been studied. Since PLLA exposed to high-energy radiation in the presence of air is prone to chain scission reactions and large degradation, changes in molecular weight were obtained by the gel permeation chromatography (GPC). Alterations in the glass transition behaviour were investigated by differential scanning calorimetry (DSC). The apparent activation energy, ΔH*, for the glass transition was determined on the basis of the heating rate dependence of the glass transition temperature, Tg. Our findings support the fact that chain scission is the main reason for the decrease of Tg and ΔH* with the absorbed dose. At low doses, despite large changes in molecular weight, only small alterations are observed in the glass transition temperature and apparent activation energy. Further increase in the absorbed dose introduces not only significant changes in the molecular weight but also in the glass transition temperature and the activation energy. Such glass transition behavior is a manifestation of a well-known effect of molecular weight on Tg, postulated by the Fox–Flory equation. However, all the observed alterations are small and tolerable at absorbed doses required for sterilization (up to 25 kGy in most circumstances). Furthermore, this study reveals that the radiation-induced changes in the molecular weight and the glass transition temperature occur in a predictable and fairly accurate manner. Therefore, gamma radiation can be used not only for sterilization but also for tailoring desirable end-use properties of PLLA based implants.
PB  - Association of Chemical Engineers of Serbia
T2  - Hemijska industrija
T1  - Uticaj gama zračenja na molekulsku masu i staklasti prelaz PLLA
T1  - The Structure and Glass Transition Behaviour of PLLA under the Influence of Gamma Radiation
VL  - 64
IS  - 4
SP  - 275
EP  - 281
DO  - 10.2298/HEMIND100329020M
ER  - 

@article{
author = "Miličević, Dejan and Trifunović, Saša and Mudrinić, Tihana and Leskovac, Andreja and Ignjatović, Nenad and Dojčilović, Jablan and Suljovrujić, Edin",
year = "2010",
abstract = "U ovom radu ispitivan je uticaj gama zračenja na molekulsku masu i staklasti prelaz poli-L-laktida (PLLA). S obzirom da je PLLA pri izlaganju visokoenergijskom zračenju sklon kidanju lanaca i velikoj degradaciji, promene u molekulskoj masi su određene primenom gel propusne hromatografije (GPC). Radijaciono-indukovane promene u staklastom prelazu su ispitane pomoću diferencijalno skenirajuće kalorimetrije (DSC). Prividna aktivaciona energija za staklasti prelaz, ΔH*, određena je na osnovu zavisnosti temperature staklastog prelaza, Tg, od brzine zagrevanja. Kidanje lanaca, uzrokovano zračenjem, glavni je razlog opadanja Tg i ΔH* sa apsorbovanom dozom. Izazvane promene u molekulskoj masi i temperaturi staklastog prelaza odigravaju se na predvidljiv i prilično precizan način. Stoga, gama zračenje može biti korišćeno nesamo za sterilizaciju nego i za dobijanje ovog biomaterijala poželjnih karakteristika., The influence of gamma radiation on the structure and glass transition behaviour of poly-L-lactide (PLLA) has been studied. Since PLLA exposed to high-energy radiation in the presence of air is prone to chain scission reactions and large degradation, changes in molecular weight were obtained by the gel permeation chromatography (GPC). Alterations in the glass transition behaviour were investigated by differential scanning calorimetry (DSC). The apparent activation energy, ΔH*, for the glass transition was determined on the basis of the heating rate dependence of the glass transition temperature, Tg. Our findings support the fact that chain scission is the main reason for the decrease of Tg and ΔH* with the absorbed dose. At low doses, despite large changes in molecular weight, only small alterations are observed in the glass transition temperature and apparent activation energy. Further increase in the absorbed dose introduces not only significant changes in the molecular weight but also in the glass transition temperature and the activation energy. Such glass transition behavior is a manifestation of a well-known effect of molecular weight on Tg, postulated by the Fox–Flory equation. However, all the observed alterations are small and tolerable at absorbed doses required for sterilization (up to 25 kGy in most circumstances). Furthermore, this study reveals that the radiation-induced changes in the molecular weight and the glass transition temperature occur in a predictable and fairly accurate manner. Therefore, gamma radiation can be used not only for sterilization but also for tailoring desirable end-use properties of PLLA based implants.",
publisher = "Association of Chemical Engineers of Serbia",
journal = "Hemijska industrija",
title = "Uticaj gama zračenja na molekulsku masu i staklasti prelaz PLLA, The Structure and Glass Transition Behaviour of PLLA under the Influence of Gamma Radiation",
volume = "64",
number = "4",
pages = "275-281",
doi = "10.2298/HEMIND100329020M"
}

Miličević, D., Trifunović, S., Mudrinić, T., Leskovac, A., Ignjatović, N., Dojčilović, J.,& Suljovrujić, E.. (2010). Uticaj gama zračenja na molekulsku masu i staklasti prelaz PLLA. in Hemijska industrija
Association of Chemical Engineers of Serbia., 64(4), 275-281.
https://doi.org/10.2298/HEMIND100329020M

Miličević D, Trifunović S, Mudrinić T, Leskovac A, Ignjatović N, Dojčilović J, Suljovrujić E. Uticaj gama zračenja na molekulsku masu i staklasti prelaz PLLA. in Hemijska industrija. 2010;64(4):275-281.
doi:10.2298/HEMIND100329020M .

Miličević, Dejan, Trifunović, Saša, Mudrinić, Tihana, Leskovac, Andreja, Ignjatović, Nenad, Dojčilović, Jablan, Suljovrujić, Edin, "Uticaj gama zračenja na molekulsku masu i staklasti prelaz PLLA" in Hemijska industrija, 64, no. 4 (2010):275-281,
https://doi.org/10.2298/HEMIND100329020M . .