Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
The development of gas-flow modulation for high-frequency MTDSC measurements
Autore:
Royall, PG; Craig, DQM; Reading, M; Lever, TJ;
Indirizzi:
Queens Univ Belfast, Sch Pharm, Belfast BT9 7BL, Antrim, North Ireland Queens Univ Belfast Belfast Antrim North Ireland BT9 7BL m, North Ireland Univ Loughborough, ITPME, Loughborough LE11 3TU, Leics, England Univ Loughborough Loughborough Leics England LE11 3TU 3TU, Leics, England TA Instruments Ltd, Leatherhead KT22 7UQ, Surrey, England TA Instruments Ltd Leatherhead Surrey England KT22 7UQ Q, Surrey, England
Titolo Testata:
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
fascicolo: 3, volume: 60, anno: 2000,
pagine: 795 - 805
SICI:
1388-6150(2000)60:3<795:TDOGMF>2.0.ZU;2-F
Fonte:
ISI
Lingua:
ENG
Soggetto:
DIFFERENTIAL SCANNING CALORIMETRY; GLASS-TRANSITION; SYSTEMS; DSC;
Keywords:
forced gas-flow accessory; gas-flow modulation; high-frequency temperature modulation; MTDSC; PET and Saquinavir;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
13
Recensione:
Indirizzi per estratti:
Indirizzo: Royall, PG Queens Univ Belfast, Sch Pharm, 97 Lisburn Rd, Belfast BT9 7BL,Antrim, North Ireland Queens Univ Belfast 97 Lisburn Rd Belfast Antrim North Ireland BT9 7BL
Citazione:
P.G. Royall et al., "The development of gas-flow modulation for high-frequency MTDSC measurements", J THERM ANA, 60(3), 2000, pp. 795-805

Abstract

The purpose of this study was to investigate the feasibility of modulatingthe temperature programme of a conventional DSC by use of an alternating gas-flow system. Modulated temperature differential scanning calorimetry (MTDSC) is an important thermal analysis technique but suffers from a limited applicable frequency range due to the mass of the sample and DSC cell leading to the impingement of thermal conductivity effects. We suggest that the frequency limit can be increased by replacing the cell as the source of temperature modulation with an external gaseous source, directed towards the sample and reference pans. In this evaluation, an alternating gas-flow was passed through a line to a forced gas-flow accessory (FGFA). The FGFA consisted of two matched cylinders containing chambers that allowed pre-temperature-equilibration of the stream of gas before it was passed over the sample and reference pans. The development of this device revealed the essential practical requirements of gas-flow modulation for high-frequency temperaturemodulation. These include the following: an appropriately sealed tunable gas supply to both sample and reference pans, an effective method for high-frequency cycling of the gas-flow rate, a small aperture to deliver the flowing gas directly over the pan and a temperature equilibration chamber. The results from samples of quenched PET and amorphous Saquinavir indicate thatgas-flow modulation is indeed feasible, with the FGFA able to raise the attainable temperature modulation frequency by an order of magnitude comparedto conventional MTDSC.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 07/04/20 alle ore 04:18:32