Ib pawg kws tshawb fawb los ntawm Brown University tau kawm txog qhov teeb meem uas tau nyob ntev yam tsis muaj kev daws teeb meem. Yog li, nyob rau hauv ib lub sij hawm, ib tug tsis tshua muaj zog polymer PBO (polybenzoxazole) tau npaj rau lub cev armor. Raws li polybenzoxazole, serial lub cev armor tau tsim rau US Army, tab sis tom qab qee lub sij hawm lawv raug tshem tawm. Nws muab tawm hais tias cov khoom ntawm lub cev armor yog raug rau unpredictable kev puas tsuaj nyob rau hauv tus ntawm ya raws. Qhov no tsis tiv thaiv kev tsim thiab muag khoom ntawm lub cev armor los ntawm ntau yam kev hloov kho ntawm PBO raws li Zylon hom, tab sis kev ntseeg siab ntawm cov ntaub ntawv tseem tshuav ntau yam xav tau.
Qhov teeb meem nrog PBO qhov kev ntseeg tau yog tias nws siv cov corrosive polyphosphoric acid (PPA) tsis tshua muaj zog los rhuav tshem cov saw hlau polymer thaum lub sij hawm tsim khoom. Cov kua qaub ua haujlwm raws li cov kuab tshuaj thiab ua cov catalyst. Cov kua qaub molecules nyob rau hauv lub polymer molecules tom qab ua rau lawv tus kheej hnov ββthaum lub sij hawm ua hauj lwm ntawm lub cev armor los ntawm kev npaj txhij txog kev puas tsuaj ntawm cov khoom. Yog tias koj hloov PPA nrog qee yam tsis zoo, kev ua haujlwm ntawm PBO polymers tuaj yeem txhim kho tau zoo, tab sis yog dab tsi?
Cov kws tshawb fawb los ntawm Brown University siv PBO ua lub zog rau kev tsim cov saw hlau molecular ib qho alloy ntawm kub (Au) thiab palladium (Pd) nanoparticles. Thaum lub sij hawm kev sim, qhov pom kev sib piv ntawm ib qho thiab lwm qhov tau txheeb xyuas - 40% kub thiab 60% palladium - uas ua rau kom nrawm tshaj plaws ntawm cov khoom siv polymer. Hauv qhov no, cov kuab tshuaj yog formic acid, ib puag ncig tus phooj ywg thiab cov khoom siv txuas ntxiv dua tshiab. Feem ntau, cov txheej txheem thev naus laus zis tshiab tsis tshua muaj zog-intensive thiab tsis kim li siv polyphosphoric acid.
Tom qab tsim cov ntim txaus ntawm PBO polymer siv txoj kev tshiab, nws tau sim los ntawm boiling hauv dej thiab kua qaub rau ntau hnub. Cov khoom siv tsis tau degradation, uas ua rau muaj kev cia siab rau qhov ua tau zoo ntawm lub cev armor vests siv nws. Ib tsab xov xwm mob siab rau qhov kev tshawb fawb no tau luam tawm hauv phau ntawv journal .
Tau qhov twg los: 3d xov.ru