When Allah created material things from absolute nothingness, does it mean that His Power was converted into material power and material form?

When Allah created material things from absolute nothingness, does it mean that His Power was converted into material power and material form?
Concise answer
If you mean conversion of divine power into material power, there is no doubt that such a notion is false and it is never true with God. If you mean by the word "conversion" reflection of God's power, indeed creation from absolute nothingness gives such a meaning because ‘nothing' was not something to be created. The narrations also state that when God, Whose power is united with other divine powers and which we cannot comprehend, created the creatures out of nothing, the creatures were in fact like mirrors which reflected (manifested) His absolute power.
The term "reflection"[1] has been referred to with the expression "extension of attribute" in the narrations: "God was our Lord from eternity, and knowledge was His essence. He was knowing when there was nothing to be known. Hearing was His Essence when there was nothing to be heard. Seeing was His essence when there was nothing to be seen. Power was His essence when there was no affordable thing. When He created things and those things became known, God's knowledge extended to the known, His hearing to the heard and His seeing to the seen and His power to the afforded."[2]
That is to say, God is absolute and there is no distinction in His essence in terms of the attributes. So we cannot know the attributes unless God creates something. It is only after creation of something that we know that God's creature bears the attributes of the Creator and manifests those of His. That is why God is known through His creatures or ayāt (signs). It has been narrated in a Qudsi tradition that God, the Exalted, said:
«کنت کنزاً مخفیاً فاحببت أن أعرف فخلقت الخلق لکی أعرف»
"I was a hidden treasure, so I loved to I be known, so I created the creatures so as to be known."[3]

[1] Reflection in reality refers to manifestation or epiphany [tajalli] in mystical terminology.
[2] The Arabic version of the hadith is the following:
«عَنْ أَبِی بَصِیرٍ قَالَ سَمِعْتُ أَبَا عَبْدِ اللَّهِ ع یَقُولُ لَمْ یَزَلِ اللَّهُ عَزَّ وَ جَلَّ رَبَّنَا وَ الْعِلْمُ ذَاتُهُ وَ لَا مَعْلُومَ وَ السَّمْعُ ذَاتُهُ وَ لَا مَسْمُوعَ وَ الْبَصَرُ ذَاتُهُ وَ لَا مُبْصَرَ وَ الْقُدْرَةُ ذَاتُهُ وَ لَا مَقْدُورَ فَلَمَّا أَحْدَثَ الْأَشْیَاءَ وَ کَانَ الْمَعْلُومُ وَقَعَ الْعِلْمُ مِنْهُ عَلَى الْمَعْلُومِ وَ السَّمْعُ عَلَى الْمَسْمُوعِ وَ الْبَصَرُ عَلَى الْمُبْصَرِ وَ الْقُدْرَةُ عَلَى الْمَقْدُورِ»
Kulayni, al-Kafi, vol.1, p. 107, Dar al-Kutub al-Islamiyah, Tehran, 1365 (1986).
[3] Qazi Noorullah Shushtari, Ihqaq al-Haqq, vol.1, p. 431, Ayatollah Marashi Najafi Library, qom, 1409 A.H.